Login In
2007 Volume 24 Issue 7
2007, 24(7): 729-736
Abstract:
As important organic photochromic compounds,spirooxazines exhibit excellent chemical stability,photosensitivity and photofatigue resistance,and have potential applications in the fields of light filters,camouflage and optical data recording & storage.The design & synthesis of spirooxazines has been a focus in the field in order to obtain photochromic spirooxazines with the better performance.Based on the basic synthetic methods of photochromic spirooxazines compounds,the typical synthetic methods and photochromic properties of spirooxazines,including biphotochromic spirooxazines and photochromic siprooxazine polymers,are reviewed.The influence of main structure of spirooxazine on the photochromic properties is briefly discussed.The introduction of ultrasound and microwave in the synthesis of spirooxazine is presented.The important study direction in the synthesis of spirooxazines is suggested.
As important organic photochromic compounds,spirooxazines exhibit excellent chemical stability,photosensitivity and photofatigue resistance,and have potential applications in the fields of light filters,camouflage and optical data recording & storage.The design & synthesis of spirooxazines has been a focus in the field in order to obtain photochromic spirooxazines with the better performance.Based on the basic synthetic methods of photochromic spirooxazines compounds,the typical synthetic methods and photochromic properties of spirooxazines,including biphotochromic spirooxazines and photochromic siprooxazine polymers,are reviewed.The influence of main structure of spirooxazine on the photochromic properties is briefly discussed.The introduction of ultrasound and microwave in the synthesis of spirooxazine is presented.The important study direction in the synthesis of spirooxazines is suggested.
2007, 24(7): 737-741
Abstract:
Polypropylenes grafted with AA were prepared by reactive extrusion with pre-irradiated PP (rPP) as the homogeneous initiator.The effect of pre-irradiated dose,fraction of rPP and concentration of acrylic acid on grafting reaction was studied,and the grafted PP was characterized by means of Fourier transition infrared spectroscopy (FTIR),differential scanning calorimetry (DSC) and polarized light microscopy (PLM).The results show that the degradation of PP was suppressed effectively with this novel method for preparing PP-g-AA copolymers,and grafted copolymers with good mechanical properties were obtained.It was found that the product with higher Gd (0.19%) and relatively excellent mechanical properties can be produced if the mass ratio of PP/rPP/AA is 90:10:0.8,where selected preirradiation dose of rPP is 4 kGy.Moreover,an adhesive strength of 4.88 kN/m was reached in the PP-g-AA/aluminium laminate.
Polypropylenes grafted with AA were prepared by reactive extrusion with pre-irradiated PP (rPP) as the homogeneous initiator.The effect of pre-irradiated dose,fraction of rPP and concentration of acrylic acid on grafting reaction was studied,and the grafted PP was characterized by means of Fourier transition infrared spectroscopy (FTIR),differential scanning calorimetry (DSC) and polarized light microscopy (PLM).The results show that the degradation of PP was suppressed effectively with this novel method for preparing PP-g-AA copolymers,and grafted copolymers with good mechanical properties were obtained.It was found that the product with higher Gd (0.19%) and relatively excellent mechanical properties can be produced if the mass ratio of PP/rPP/AA is 90:10:0.8,where selected preirradiation dose of rPP is 4 kGy.Moreover,an adhesive strength of 4.88 kN/m was reached in the PP-g-AA/aluminium laminate.
2007, 24(7): 742-746
Abstract:
4-(5-Methyl-oxadiazole)-phenyl-1,3 butyl diketonate was synthesized via dehydration reaction of 4-acetyl phenylformic ester and hydrazine hydrate,and characterized by IR and 1H NMR.UV-Vis spectra and electrochemical characteristics of the compound were investigated.In addition,the energy gap (Eg) was evaluated to be 2.72 eV from the onset absorption wavelength (λonset/nm) of the UV-Vis spectra,and the energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) were calculated by cyclic voltammetry (CV) and UV-Vis spectrometry.The measurement results of the energy levels indicate that the electron affinity of the compound is higher than that of PBD which is the normal electron-transporting material.Thus it could improve the efficiency of the electroluminescent device when it is used as electron transport layer.
4-(5-Methyl-oxadiazole)-phenyl-1,3 butyl diketonate was synthesized via dehydration reaction of 4-acetyl phenylformic ester and hydrazine hydrate,and characterized by IR and 1H NMR.UV-Vis spectra and electrochemical characteristics of the compound were investigated.In addition,the energy gap (Eg) was evaluated to be 2.72 eV from the onset absorption wavelength (λonset/nm) of the UV-Vis spectra,and the energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) were calculated by cyclic voltammetry (CV) and UV-Vis spectrometry.The measurement results of the energy levels indicate that the electron affinity of the compound is higher than that of PBD which is the normal electron-transporting material.Thus it could improve the efficiency of the electroluminescent device when it is used as electron transport layer.
2007, 24(7): 747-751
Abstract:
The stabilities of the adsorption films of the o/w emulsions were investigated with a home made drop stability apparatus in which isopropyl myristate (IPM) was used as the oil and Pluronic copolymers (L61,L64,F68 and F108),lecithin (PC) and their mixture were used as the emulsifier,respectively.The results show that Pluronic molecule with a long PEO block benefited the stabilization of the film.When single Pluronic copolymer was used as the emulsifier,however,the limited length of the PPO blocks restricted their bending to insert the oil drop,resulting in the reduction of the compactness of the molecules arranging at the oil/water interface because of the repulsion between the long PEO blocks.The addition of PC improved the arrangement of the emulsifier molecules at the oil/water interface and promoted them to pack tightly.Thus the long PEO blocks wrapped on the surface of oil drop stabilized the oil-drops in water.The present work has demonstrated that the mixed emulsifiers of F68+PC or F108+PC with 0.012 5 g/mL Pluronics and 0.016 7 g/mL PC can form a stable adsorption film at the oil/water interface.
The stabilities of the adsorption films of the o/w emulsions were investigated with a home made drop stability apparatus in which isopropyl myristate (IPM) was used as the oil and Pluronic copolymers (L61,L64,F68 and F108),lecithin (PC) and their mixture were used as the emulsifier,respectively.The results show that Pluronic molecule with a long PEO block benefited the stabilization of the film.When single Pluronic copolymer was used as the emulsifier,however,the limited length of the PPO blocks restricted their bending to insert the oil drop,resulting in the reduction of the compactness of the molecules arranging at the oil/water interface because of the repulsion between the long PEO blocks.The addition of PC improved the arrangement of the emulsifier molecules at the oil/water interface and promoted them to pack tightly.Thus the long PEO blocks wrapped on the surface of oil drop stabilized the oil-drops in water.The present work has demonstrated that the mixed emulsifiers of F68+PC or F108+PC with 0.012 5 g/mL Pluronics and 0.016 7 g/mL PC can form a stable adsorption film at the oil/water interface.
2007, 24(7): 752-756
Abstract:
A series of La0.67Sr0.33MnO3 perovskite oxides was prepared by the sol-gel method.The grain sizes increase abnormally and the grain boundary effects are very prominent for the samples sintered at above 1 573 K.The magnetic strength increases with the sintering temperature.However,the Curie temperatures of all the samples keep constant.The metal-semiconductor behavior can be observed for the samples sintered at 1 173 K and 1 573 K.At proper sintering temperature,both tunneling magnetoresistance (TMR) and colossal magnetoresistance (CMR) can be observed.It indicates the transport of spintronics is related not only to the particle size and the density of the sample,but also to the microstructure of grain boundary.
A series of La0.67Sr0.33MnO3 perovskite oxides was prepared by the sol-gel method.The grain sizes increase abnormally and the grain boundary effects are very prominent for the samples sintered at above 1 573 K.The magnetic strength increases with the sintering temperature.However,the Curie temperatures of all the samples keep constant.The metal-semiconductor behavior can be observed for the samples sintered at 1 173 K and 1 573 K.At proper sintering temperature,both tunneling magnetoresistance (TMR) and colossal magnetoresistance (CMR) can be observed.It indicates the transport of spintronics is related not only to the particle size and the density of the sample,but also to the microstructure of grain boundary.
2007, 24(7): 757-760
Abstract:
Cobalt doped MCM-41 was used to catalyze the oxidation of diphenylmethane to benzophenone.The effect of solvent,amount of acetic acid glacial,reaction time,catalyst concentration,and reaction temperature on the catalyst performance were examined in order to optimize the conversion of diphenylmethane and the selectivity of benzophenone.A 95.8% selectivity to benzophenone was obtained at 21% conversion of diphenylmethane under the optimum reaction conditions:m(diphenylmethane):m(catalyst)=1:10,V(diphenylmethane):V(acetic acid glacial)=1:10,reaction temperature=100℃ and reaction time=10 h.
Cobalt doped MCM-41 was used to catalyze the oxidation of diphenylmethane to benzophenone.The effect of solvent,amount of acetic acid glacial,reaction time,catalyst concentration,and reaction temperature on the catalyst performance were examined in order to optimize the conversion of diphenylmethane and the selectivity of benzophenone.A 95.8% selectivity to benzophenone was obtained at 21% conversion of diphenylmethane under the optimum reaction conditions:m(diphenylmethane):m(catalyst)=1:10,V(diphenylmethane):V(acetic acid glacial)=1:10,reaction temperature=100℃ and reaction time=10 h.
2007, 24(7): 761-764
Abstract:
The interaction between alpha-lipoic acid (ALA) and bovine serum albumin (BSA) was studied via fluorescence and ultraviolet-visible absorption spectra in buffer at different temperatures.The results indicate that static quenching was involved in added ALA in BSA solution and the quenching constant (KSV) was 4.65×103 L/mol (26℃) and 4.46×103 L/mol (37℃) respectively.The energy transfer efficiency E is 5% and the distance r is 2.90 nm between drug and serum albumin according to Förster's non-radiation energy transfer.The binding constants is 4.31×103 L/mol (26℃) and 4.27×103 L/mol (37℃) respectively and they react at a molar ratio of 1:1.The interaction between alpha-lipoic acid and bovine serum albumin is driven mainly by eletro-static force according to thermodynamic parameters.
The interaction between alpha-lipoic acid (ALA) and bovine serum albumin (BSA) was studied via fluorescence and ultraviolet-visible absorption spectra in buffer at different temperatures.The results indicate that static quenching was involved in added ALA in BSA solution and the quenching constant (KSV) was 4.65×103 L/mol (26℃) and 4.46×103 L/mol (37℃) respectively.The energy transfer efficiency E is 5% and the distance r is 2.90 nm between drug and serum albumin according to Förster's non-radiation energy transfer.The binding constants is 4.31×103 L/mol (26℃) and 4.27×103 L/mol (37℃) respectively and they react at a molar ratio of 1:1.The interaction between alpha-lipoic acid and bovine serum albumin is driven mainly by eletro-static force according to thermodynamic parameters.
2007, 24(7): 765-769
Abstract:
Five chalcones were synthesized via the aldol condensation reaction of acetophenone or para-substituted acetophenones with 1-phenyl-3-methyl-5-phenoxyl-pyrazol-4-aldehyde,which reacted with two kinds of hydrazine in glacial acetic acid under refluxing to give a series of bipyrazoline derivatives.In this synthetic course,glacial acetic acid is not only a solvent,but also a catalyzer.An optimal yield of 72% was achieved when the reaction was carried out in refluxing.The structures of the compounds were confirmed by means of IR spectrum,1H NMR and elemental analysis.The fluorescent spectra of the prepared compounds show that compounds 3a~3e emits blue fluorescence,the emission wavelength was at about 377 nm.Compounds 4a~4e emits purple fluorescence,the emission wavelength was at about 480 nm.In the fluorescence spectrum,the bipyrazoline compounds of different substituents have diferent fluorescence intensity,compound 4e shows a maximum fluorescence intensity of 4 694.The results show that the compounds may be better fluorescence materials.
Five chalcones were synthesized via the aldol condensation reaction of acetophenone or para-substituted acetophenones with 1-phenyl-3-methyl-5-phenoxyl-pyrazol-4-aldehyde,which reacted with two kinds of hydrazine in glacial acetic acid under refluxing to give a series of bipyrazoline derivatives.In this synthetic course,glacial acetic acid is not only a solvent,but also a catalyzer.An optimal yield of 72% was achieved when the reaction was carried out in refluxing.The structures of the compounds were confirmed by means of IR spectrum,1H NMR and elemental analysis.The fluorescent spectra of the prepared compounds show that compounds 3a~3e emits blue fluorescence,the emission wavelength was at about 377 nm.Compounds 4a~4e emits purple fluorescence,the emission wavelength was at about 480 nm.In the fluorescence spectrum,the bipyrazoline compounds of different substituents have diferent fluorescence intensity,compound 4e shows a maximum fluorescence intensity of 4 694.The results show that the compounds may be better fluorescence materials.
2007, 24(7): 770-773
Abstract:
The electrochemical behavior of Dopamine (DA) and Ascorbic Acid (AA) at both carbon paste electrode (CPE) and in situ CPB modified carbon paste electrode (CPB/CPE) was investigated.On the surface of CPB/CPE electrode,owing to the electrostatic interaction of CPB and negatively charged AA,the oxidation peak potential shifted more negatively and the peak current increased.On the other hand,the positively charged DA was repelled from the electrode surface and the oxidation peak potential shifted more positively and the peak current decreased.The anodic potential difference between AA and DA is about 340 mV,and AA does not interfere with the electroanalytical determination of DA at CPB/CPE.Linear calibration curves were obtained for both AA and DA in a concentration range of 1.0×10-5~5.0×10-3 mol/L.The detection limit of DA in the presence of AA 100- fold that of DA was 2.0×10-6 mol/L.The CPB/CPE was used to determine DA in dopamine injection samples spiked with AA.
The electrochemical behavior of Dopamine (DA) and Ascorbic Acid (AA) at both carbon paste electrode (CPE) and in situ CPB modified carbon paste electrode (CPB/CPE) was investigated.On the surface of CPB/CPE electrode,owing to the electrostatic interaction of CPB and negatively charged AA,the oxidation peak potential shifted more negatively and the peak current increased.On the other hand,the positively charged DA was repelled from the electrode surface and the oxidation peak potential shifted more positively and the peak current decreased.The anodic potential difference between AA and DA is about 340 mV,and AA does not interfere with the electroanalytical determination of DA at CPB/CPE.Linear calibration curves were obtained for both AA and DA in a concentration range of 1.0×10-5~5.0×10-3 mol/L.The detection limit of DA in the presence of AA 100- fold that of DA was 2.0×10-6 mol/L.The CPB/CPE was used to determine DA in dopamine injection samples spiked with AA.
2007, 24(7): 774-777
Abstract:
A new greeen chemosynthesis of 4-hydroxyphenyl-1'-O-D-glucopyrano-side,arbutin and its anomer α-arbutin,is reported.With solid acid,montmorillonite K-10 or 4A molecular sieves as catalysts,benzyl-protected donor (2) or α-trichloroacetimidate (3) was glycosylated with hydroquinone to obtain intermediate (4) in a yield of 86%,and then compound (1) was quantitatively obtained after the deprotection.This method is very benign to environment.The structure of compound (4) was confirmed by IR,MS,1H NMR and elemental analysis,and the data of target compound (1) are the same as those from references.
A new greeen chemosynthesis of 4-hydroxyphenyl-1'-O-D-glucopyrano-side,arbutin and its anomer α-arbutin,is reported.With solid acid,montmorillonite K-10 or 4A molecular sieves as catalysts,benzyl-protected donor (2) or α-trichloroacetimidate (3) was glycosylated with hydroquinone to obtain intermediate (4) in a yield of 86%,and then compound (1) was quantitatively obtained after the deprotection.This method is very benign to environment.The structure of compound (4) was confirmed by IR,MS,1H NMR and elemental analysis,and the data of target compound (1) are the same as those from references.
2007, 24(7): 778-781
Abstract:
Enzymatic esterification of glycerol and n-caprylic acid was studied under the catalysis of Novozyme 435 by means of microwave irradiation and conventional heating.Microwave irradiation increased initial reaction rate more than conventional heating did,and the initial reaction rate increased with increasing reaction temperature for both heating modes at 50~75℃.The contents of 2-monoglyceride and 1,2-diglyceride in the microwaved reaction mixture were higher than those in thermo heated reaction mixture,but the irradiation didn't change the lipase's 1,3-specificity.In general the microwave irradiation weakens the 1,3-specificity of enzymatic glycerol esterification of Novozyme 435 and the weakening effect is related to the reaction conditions.By conventional heating,the molar ratios of 1-monoglyceride to 2-monoglyceride (1-MG/2-MG) in the product were 26.9~43.4,and the ratio of 1,3-diglyceride to 1,2-diglyceride (1,3-DG/1,2-DG) were 10.5~19.6;whereas by microwave irradiation,the 1-MG/2-MG were decreased to 16.2~40.4 and the 1,3-DG/1,2-DG became 7.6~15.3.
Enzymatic esterification of glycerol and n-caprylic acid was studied under the catalysis of Novozyme 435 by means of microwave irradiation and conventional heating.Microwave irradiation increased initial reaction rate more than conventional heating did,and the initial reaction rate increased with increasing reaction temperature for both heating modes at 50~75℃.The contents of 2-monoglyceride and 1,2-diglyceride in the microwaved reaction mixture were higher than those in thermo heated reaction mixture,but the irradiation didn't change the lipase's 1,3-specificity.In general the microwave irradiation weakens the 1,3-specificity of enzymatic glycerol esterification of Novozyme 435 and the weakening effect is related to the reaction conditions.By conventional heating,the molar ratios of 1-monoglyceride to 2-monoglyceride (1-MG/2-MG) in the product were 26.9~43.4,and the ratio of 1,3-diglyceride to 1,2-diglyceride (1,3-DG/1,2-DG) were 10.5~19.6;whereas by microwave irradiation,the 1-MG/2-MG were decreased to 16.2~40.4 and the 1,3-DG/1,2-DG became 7.6~15.3.
2007, 24(7): 782-785
Abstract:
The solid-liquid surface reaction method was employed for the preparation of diallyl trisulfide-bonded silica gel (DTS).The γ-mercaptopropyl-bonded silica gel (MPS) was firstly obtained with coupling reagent and silica gel.Then diallyl trisulfide-bonded silica gel (DTS) was prepared by the mercapto-alkylene addition reaction between coupling reagent silica gel and diallyl trisulfide in the presence of initiator.The surface structure of DTS was characterized by elemental analysis,FT-IR,thermal analysis and electrospray mass spectrometry.The bonded amounts of MPS and DTS were 1.73 mmol/g and 0.27 mmol/g,respectively.The antibacterial property of prepared material DTS was investigated via antibacterium-circle.The antibacterium-circles of DTS to Staphylococcus aureus,Escherichia coli,Bacillus subtilis,Aerobacter aerogenes and Proteus vulgaris were 9.0 mm,8.1 mm,10.1 mm,9.2 mm and 8.9 mm,respectively.The influence of the content of DTS in beef extract peptone medium on the inhibition effect to Staphylococcus aureus and Escherichia coli by mixing-smearing plate cultivate method was also investigated.The results showed that DTS exhibits a good inhibition effect on these five bacteria.After chemically bonding,not only elimination of the strong odour of Allium Sativum L,but also preservation of the antibacterial activity were found on the surface of DTS.Meanwhile,the antibacterial mechanism of DTS was proposed based on the experimental result analysis.A mixing-smearing plate culture method can be provided for the antibacterial test of the hydrophobic particle samples.
The solid-liquid surface reaction method was employed for the preparation of diallyl trisulfide-bonded silica gel (DTS).The γ-mercaptopropyl-bonded silica gel (MPS) was firstly obtained with coupling reagent and silica gel.Then diallyl trisulfide-bonded silica gel (DTS) was prepared by the mercapto-alkylene addition reaction between coupling reagent silica gel and diallyl trisulfide in the presence of initiator.The surface structure of DTS was characterized by elemental analysis,FT-IR,thermal analysis and electrospray mass spectrometry.The bonded amounts of MPS and DTS were 1.73 mmol/g and 0.27 mmol/g,respectively.The antibacterial property of prepared material DTS was investigated via antibacterium-circle.The antibacterium-circles of DTS to Staphylococcus aureus,Escherichia coli,Bacillus subtilis,Aerobacter aerogenes and Proteus vulgaris were 9.0 mm,8.1 mm,10.1 mm,9.2 mm and 8.9 mm,respectively.The influence of the content of DTS in beef extract peptone medium on the inhibition effect to Staphylococcus aureus and Escherichia coli by mixing-smearing plate cultivate method was also investigated.The results showed that DTS exhibits a good inhibition effect on these five bacteria.After chemically bonding,not only elimination of the strong odour of Allium Sativum L,but also preservation of the antibacterial activity were found on the surface of DTS.Meanwhile,the antibacterial mechanism of DTS was proposed based on the experimental result analysis.A mixing-smearing plate culture method can be provided for the antibacterial test of the hydrophobic particle samples.
2007, 24(7): 786-789
Abstract:
Gold nanoparticles were prepared via a simple photoreduction technique in the presence of Keggin heteropolyacid doped with different transition metals (PW11M),in which the Keggin heteropolyacid acted as reducing agent,photocatalyst and stabilizer.The results indicate that formation rate and morphology of the particles strongly depend on the kind of transition metal doped in the heteropolyacid and the preparing conditions such as irradiation time and propan-2-ol amount.The photoreduction rates of PW11Zn and PW11Fe are faster than those of PW11Ni and PW11Cu.The shapes of the nanoparticles synthesized in the presence of PW11Fe and PW11Zn are nearly uniform spheres,while the morphologies of the nanoparticles synthesized in the presence of PW11Ni and PW11Cu are found to contain a mixture of flat triangular/hexagonal structures as well as spheres.The increases of irradiation time and propan-2-ol amount can make the morphology of the nanoparticles more uniform and shorten the formation time of the nanoparticles.
Gold nanoparticles were prepared via a simple photoreduction technique in the presence of Keggin heteropolyacid doped with different transition metals (PW11M),in which the Keggin heteropolyacid acted as reducing agent,photocatalyst and stabilizer.The results indicate that formation rate and morphology of the particles strongly depend on the kind of transition metal doped in the heteropolyacid and the preparing conditions such as irradiation time and propan-2-ol amount.The photoreduction rates of PW11Zn and PW11Fe are faster than those of PW11Ni and PW11Cu.The shapes of the nanoparticles synthesized in the presence of PW11Fe and PW11Zn are nearly uniform spheres,while the morphologies of the nanoparticles synthesized in the presence of PW11Ni and PW11Cu are found to contain a mixture of flat triangular/hexagonal structures as well as spheres.The increases of irradiation time and propan-2-ol amount can make the morphology of the nanoparticles more uniform and shorten the formation time of the nanoparticles.
2007, 24(7): 790-795
Abstract:
All-Si-β zeolites (Si/Al>1 200) were synthesized under hydrothermal conditions with fumed silica (SiO2) as the silica source,tetraethyl ammonium hydroxide (TEAOH) as the template and sodium fluoride (NaF) as the mineral agent.The effects of the chemical composition of the starting materials on the crystallization of All-Si-β zeolites were investigated.The structural characteristics of the products were determined by means of XRD,IR,TG/DTA and SEM.The results indicate that all-Si-β zeolites can be synthesized from the mixture at a ratio of n(SiO2):n((TEA)2O):n(H2O):n(NaF)=60:(17~18):(480~660):(5~40);the gels obtained were then transferred to a 20 mL tetrafluoroethylene-lined stainless-steel autoclave and kept in oven at 140℃ for 12 d.All-Si-β zeolites were used as catalysts in the hydroxylation of phenol with H2O2 as the oxidant.The results show that all-Si-β zeolites have high catalytic activity.When reaction temperature was 80℃,reaction time 6 h,m(Catalyst):m(Phenol)=1:20,m(Phenol)/m(H2O)=0.6 and n(Phenol)/n(H2O2)=2,the final conversion of phenol was 34.6%,the effective conversion of H2O2 was 61.2%,the yield selectivities for CAT and HQ were 69.8% and 27.0% respectively.
All-Si-β zeolites (Si/Al>1 200) were synthesized under hydrothermal conditions with fumed silica (SiO2) as the silica source,tetraethyl ammonium hydroxide (TEAOH) as the template and sodium fluoride (NaF) as the mineral agent.The effects of the chemical composition of the starting materials on the crystallization of All-Si-β zeolites were investigated.The structural characteristics of the products were determined by means of XRD,IR,TG/DTA and SEM.The results indicate that all-Si-β zeolites can be synthesized from the mixture at a ratio of n(SiO2):n((TEA)2O):n(H2O):n(NaF)=60:(17~18):(480~660):(5~40);the gels obtained were then transferred to a 20 mL tetrafluoroethylene-lined stainless-steel autoclave and kept in oven at 140℃ for 12 d.All-Si-β zeolites were used as catalysts in the hydroxylation of phenol with H2O2 as the oxidant.The results show that all-Si-β zeolites have high catalytic activity.When reaction temperature was 80℃,reaction time 6 h,m(Catalyst):m(Phenol)=1:20,m(Phenol)/m(H2O)=0.6 and n(Phenol)/n(H2O2)=2,the final conversion of phenol was 34.6%,the effective conversion of H2O2 was 61.2%,the yield selectivities for CAT and HQ were 69.8% and 27.0% respectively.
2007, 24(7): 796-800
Abstract:
The backing sand can affect oil production by entering the borehole with formation fluid during the development of unconsolidated sandstone.In view of the backing sand problem,we developed a new antiswe-lling and sand inhibiting agent NTW-1.In-door evaluation of the performance indicated that it had both antiswelling and sand inhibiting abilities and a better effect than other common sand inhibiting agents and clay inhibitors by 10.5% and 65.6% in average,and it could be used easily and economically in the field.A new idea of deep sand firming was proposed according to reservoir sanding mechanism,and a new formula developed on the basis of the composite agent NTW-1.The system could enhance the binding force between backing sand and framework sand,and inhibit the migration of deep backing sand,and reduce sanding room.The success rate and life of sand controlling were enhanced by 8.8% and 37.3%,respectively,and the oil production rate was increased by 46.2%.
The backing sand can affect oil production by entering the borehole with formation fluid during the development of unconsolidated sandstone.In view of the backing sand problem,we developed a new antiswe-lling and sand inhibiting agent NTW-1.In-door evaluation of the performance indicated that it had both antiswelling and sand inhibiting abilities and a better effect than other common sand inhibiting agents and clay inhibitors by 10.5% and 65.6% in average,and it could be used easily and economically in the field.A new idea of deep sand firming was proposed according to reservoir sanding mechanism,and a new formula developed on the basis of the composite agent NTW-1.The system could enhance the binding force between backing sand and framework sand,and inhibit the migration of deep backing sand,and reduce sanding room.The success rate and life of sand controlling were enhanced by 8.8% and 37.3%,respectively,and the oil production rate was increased by 46.2%.
2007, 24(7): 801-805
Abstract:
Both alkyl halides promoted atom transfer radical polymerization and peroxide initiated conventional polymerization of methacrylate/dimethacrylate were carried out in an attempt to explore the reaction mechanism of atom transfer radical polymerization in crosslinking systems.The kinetics of the two systems were investigated by DSC.The development of the networks was monitored based on the measurements of gel fraction and swelling ratio.The molecular mass of the primary chains before and after gelation were determined using GPC and an Ubbelohde viscometer.It was found that the polymerization rate of the ATRP system was much lower than that of the BPO system,and the molecular mass of the primary chains increased with vinyl group conversion before and after gelation,but leveled off at a higher conversion.For the three ATRP crosslinking systems with 2.5%,5%,7.5% of PEGDMA as the crosslinking monomer,respectively,the increase in molecular mass leveled off at the conversions of 70%,60%,45% in turn.These results suggest that the ATRP of methacrylate/dimethacrylate crosslinking system had "living"/controlled character,but this character would disappear when the network density arrived at a certain level.
Both alkyl halides promoted atom transfer radical polymerization and peroxide initiated conventional polymerization of methacrylate/dimethacrylate were carried out in an attempt to explore the reaction mechanism of atom transfer radical polymerization in crosslinking systems.The kinetics of the two systems were investigated by DSC.The development of the networks was monitored based on the measurements of gel fraction and swelling ratio.The molecular mass of the primary chains before and after gelation were determined using GPC and an Ubbelohde viscometer.It was found that the polymerization rate of the ATRP system was much lower than that of the BPO system,and the molecular mass of the primary chains increased with vinyl group conversion before and after gelation,but leveled off at a higher conversion.For the three ATRP crosslinking systems with 2.5%,5%,7.5% of PEGDMA as the crosslinking monomer,respectively,the increase in molecular mass leveled off at the conversions of 70%,60%,45% in turn.These results suggest that the ATRP of methacrylate/dimethacrylate crosslinking system had "living"/controlled character,but this character would disappear when the network density arrived at a certain level.
2007, 24(7): 806-809
Abstract:
An optical chemical sensor was developed for the determination of Lead (Ⅱ) based on the reversible fluorescence quenching of Meso-(4-MethyloxypHenyl) PorpHyrin (TMOPP) immobilized in a plasticized poly (vinyl chloride)(PVC) membrane.The optimum membrane of the sensor is composed of 50 mg of PVC,100 mg of bis (2-ethytbexyl) sebacate (DOS) and 3.0 mg of TMOPP.The maximum response of the optode membrane for Lead (Ⅱ) was obtained in a Tris/HCl buffer solution of pH=9.0.Under the optimum conditions described,the proposed sensor responds linearly in a concentration range of 7.90×10-6~6.30×10-4 mol/L,with a detection limit of 2.50×10-7 mol/L.The response time of the sensor is less than 1 min.The sensing membrane has the advantages of high reproducibility,reversibility of the fluorescence signal and good selectivity.Common anions and cations do not interfere.It was applied to the direct determination of micromount of Lead (Ⅱ) in environmental water with satisfactory result.
An optical chemical sensor was developed for the determination of Lead (Ⅱ) based on the reversible fluorescence quenching of Meso-(4-MethyloxypHenyl) PorpHyrin (TMOPP) immobilized in a plasticized poly (vinyl chloride)(PVC) membrane.The optimum membrane of the sensor is composed of 50 mg of PVC,100 mg of bis (2-ethytbexyl) sebacate (DOS) and 3.0 mg of TMOPP.The maximum response of the optode membrane for Lead (Ⅱ) was obtained in a Tris/HCl buffer solution of pH=9.0.Under the optimum conditions described,the proposed sensor responds linearly in a concentration range of 7.90×10-6~6.30×10-4 mol/L,with a detection limit of 2.50×10-7 mol/L.The response time of the sensor is less than 1 min.The sensing membrane has the advantages of high reproducibility,reversibility of the fluorescence signal and good selectivity.Common anions and cations do not interfere.It was applied to the direct determination of micromount of Lead (Ⅱ) in environmental water with satisfactory result.
2007, 24(7): 810-817
Abstract:
A series of poly phenyl glycidyl ethers with different molecular mass (PPGE) was synthesized via the polymeration of phenyl glycidyl ether in the presence of n-BuLi.Sodium poly phenyl glycidyl ether sulfonate was synthesized via the sulfonation of the poly phenyl glycidyl ether with sulfuric acid.We studied the relationship between the performance of the Polymer surfactant and its structure.The result shows that the range of molecular mass of PPGE is from 1 000 to 3 000 and its sulfonation degree is from 150% to 250%,as well as the increase of the dynamic surface activity with the SPPGE concentration increase from 2.5 g/L to 20.0 g/L,while the time of the DST achieving interface equilibrium is shorted,and the DST curve becomes lower.Within the scope of the SPPGE concentration under the study,in the beginning period,the adsorption is under diffusion control regime,while in the later period,it belongs to mixed kinetic adsorption,and the higher the SPPGE concentration,the bigger the adsorption barrier εa and the smaller the effective diffusion coefficient Deff.The SPPGE has a high critic micelle concentration and its CMC is about 11.0 g/L,and is less affected by the change of sulfonation degree.The change of the molecular mass can affect the surface activity effectively,among three different SPPGE samples,the one the molecular mass of 1 595 has the lowest DST curve with CMC being 10.9 g/L and γmin being 48.93 mN/m.
A series of poly phenyl glycidyl ethers with different molecular mass (PPGE) was synthesized via the polymeration of phenyl glycidyl ether in the presence of n-BuLi.Sodium poly phenyl glycidyl ether sulfonate was synthesized via the sulfonation of the poly phenyl glycidyl ether with sulfuric acid.We studied the relationship between the performance of the Polymer surfactant and its structure.The result shows that the range of molecular mass of PPGE is from 1 000 to 3 000 and its sulfonation degree is from 150% to 250%,as well as the increase of the dynamic surface activity with the SPPGE concentration increase from 2.5 g/L to 20.0 g/L,while the time of the DST achieving interface equilibrium is shorted,and the DST curve becomes lower.Within the scope of the SPPGE concentration under the study,in the beginning period,the adsorption is under diffusion control regime,while in the later period,it belongs to mixed kinetic adsorption,and the higher the SPPGE concentration,the bigger the adsorption barrier εa and the smaller the effective diffusion coefficient Deff.The SPPGE has a high critic micelle concentration and its CMC is about 11.0 g/L,and is less affected by the change of sulfonation degree.The change of the molecular mass can affect the surface activity effectively,among three different SPPGE samples,the one the molecular mass of 1 595 has the lowest DST curve with CMC being 10.9 g/L and γmin being 48.93 mN/m.
2007, 24(7): 818-822
Abstract:
Spirocyclic pentaerythritol di (phosphate monochloride)(SPDPC) containing acid source and carbon source was prepared from phosphorus oxychloride and pentaerythritol.A new series of 2,4,8,10-tetraoxa-3,9-diphosphorus spirocyclic[5,5]undecane-3,9-dioxa-3,9-disubstituted benzoylhydrazone derivatives was synthesized from SPDPC,hydrazine hydrate (85%) and substitution benzaldehyde.Their structures were confirmed by elemental analysis,FTIR,1H NMR and MS.TG and DSC results show that the target compounds have certain thermal stability due to their higher symmetry structure,heavier molecular mass,more arylgeometry carbon and phosphorus heterocycle carbon.All the compounds are self-extinguish,when the addition amount of the compound was 10% in epoxy resin (E-44),the combustion length was about 10~20 mm in the level combustion test.The LOI was improved to 28.7% when 10% the target compound was added to epoxy E-44.These synthesized compounds have a good flame retardance.
Spirocyclic pentaerythritol di (phosphate monochloride)(SPDPC) containing acid source and carbon source was prepared from phosphorus oxychloride and pentaerythritol.A new series of 2,4,8,10-tetraoxa-3,9-diphosphorus spirocyclic[5,5]undecane-3,9-dioxa-3,9-disubstituted benzoylhydrazone derivatives was synthesized from SPDPC,hydrazine hydrate (85%) and substitution benzaldehyde.Their structures were confirmed by elemental analysis,FTIR,1H NMR and MS.TG and DSC results show that the target compounds have certain thermal stability due to their higher symmetry structure,heavier molecular mass,more arylgeometry carbon and phosphorus heterocycle carbon.All the compounds are self-extinguish,when the addition amount of the compound was 10% in epoxy resin (E-44),the combustion length was about 10~20 mm in the level combustion test.The LOI was improved to 28.7% when 10% the target compound was added to epoxy E-44.These synthesized compounds have a good flame retardance.
2007, 24(7): 823-827
Abstract:
Carbon encapsulated Fe and Ni nano particles were respectively prepared by pyrolysis of Fe and Ni-loaded cation exchange resin (Fe-Ni/D113) at 400℃,500℃,600℃ and 700℃.TG results show that the thermal stability of Fe-Ni/D113 was better than that of pure D113 resin.X-ray diffraction (XRD) and transmission electron microscopy (TEM) results show that the nano particle size increased with the pyrolysis temperature.Magnetic test result shows that the pyrolyzate obtained at 400℃ was superparamagnetic.The coercivities (Hc) at room temperature of the pyrolyzates obtained at 500℃,600℃,and 700℃ were much higher than that of the corresponding bulk materials,and the Hc value was influenced by the size of the nano particles.The saturation magnetizations (Ms) of all the pyrolyzates were lower than that of the corresponding bulk materials and increased with the pyrolysis temperature.
Carbon encapsulated Fe and Ni nano particles were respectively prepared by pyrolysis of Fe and Ni-loaded cation exchange resin (Fe-Ni/D113) at 400℃,500℃,600℃ and 700℃.TG results show that the thermal stability of Fe-Ni/D113 was better than that of pure D113 resin.X-ray diffraction (XRD) and transmission electron microscopy (TEM) results show that the nano particle size increased with the pyrolysis temperature.Magnetic test result shows that the pyrolyzate obtained at 400℃ was superparamagnetic.The coercivities (Hc) at room temperature of the pyrolyzates obtained at 500℃,600℃,and 700℃ were much higher than that of the corresponding bulk materials,and the Hc value was influenced by the size of the nano particles.The saturation magnetizations (Ms) of all the pyrolyzates were lower than that of the corresponding bulk materials and increased with the pyrolysis temperature.
2007, 24(7): 828-831
Abstract:
Multiwall carbon nanotubes (MWNT) functionalized with H20 and H40 hyperbranched polyesters were synthesized.MWNT was first purified by a 3:1 concentrated H2SO4:HNO3 mixture and further acidified in a mixture of concentrated H2SO4:30% aqueous H2O2 of 4:1 for oxidizing into carboxylate group,then the carboxyl terminated MWNT reacted with SOCl2 to form MWNT-COCl.The MWNT-COCl was reacted with the hydroxyl of hyperbranched polymer to obtain the hyperbranched polymer functionalized MWNT.The characterized results of FTIR,Raman,TEM and TG proved the existence of covalently chemical bond between nanotube and hyperbranched polymerester.The coating density of H20 was that every 321 carbon atoms were connected with one polymer chain,while the coating density of H40 was that every 842 carbon atoms were connected with one polymer chain.The dispersion of MWNT in solvent after modification was better than the dispersion of MWNT in solvent before modification.
Multiwall carbon nanotubes (MWNT) functionalized with H20 and H40 hyperbranched polyesters were synthesized.MWNT was first purified by a 3:1 concentrated H2SO4:HNO3 mixture and further acidified in a mixture of concentrated H2SO4:30% aqueous H2O2 of 4:1 for oxidizing into carboxylate group,then the carboxyl terminated MWNT reacted with SOCl2 to form MWNT-COCl.The MWNT-COCl was reacted with the hydroxyl of hyperbranched polymer to obtain the hyperbranched polymer functionalized MWNT.The characterized results of FTIR,Raman,TEM and TG proved the existence of covalently chemical bond between nanotube and hyperbranched polymerester.The coating density of H20 was that every 321 carbon atoms were connected with one polymer chain,while the coating density of H40 was that every 842 carbon atoms were connected with one polymer chain.The dispersion of MWNT in solvent after modification was better than the dispersion of MWNT in solvent before modification.
2007, 24(7): 832-834
Abstract:
Diethylthiophosphoryl chloride (A) was synthesized by reacting phosphorus thiochloride with anhydrous alcohol in the presence of NaOH,and then a novel phosphorus-nitrogen-and sulfur-containing flame retardant,1,4-di(O,O-diethyl thiophosphoryl imine) benzene (B),was synthesized via the reaction of diethylthiophosphoryl chloride with p-phenylenediamine.Compound B was characterized by elemental analysis,IR,1H NMR and MS.The thermal properties of compound B were researched based on TG and DSC curves,and the influence factors such as the solvent and catalyst on the reaction rate and the yield of compound B were also studied.The thermal property studies indicate that the mass loss of compound B was 54.39% at 242.2~750℃,and when the temperature was 1 000℃,there was 25.11% char residue left,which showed that the title compound has a good thermal stability and char forming capability.Using acetonitrile as the solvent instead of trichloromethane or 1,2-dichloethane gave higher yield.During the synthesis,the yield was very low when triethylamine was used as acid acceptor alone,and when a little amount of 4-dimethylaminopyridine (DMAP) was added at the same time,the yield could be 81%.
Diethylthiophosphoryl chloride (A) was synthesized by reacting phosphorus thiochloride with anhydrous alcohol in the presence of NaOH,and then a novel phosphorus-nitrogen-and sulfur-containing flame retardant,1,4-di(O,O-diethyl thiophosphoryl imine) benzene (B),was synthesized via the reaction of diethylthiophosphoryl chloride with p-phenylenediamine.Compound B was characterized by elemental analysis,IR,1H NMR and MS.The thermal properties of compound B were researched based on TG and DSC curves,and the influence factors such as the solvent and catalyst on the reaction rate and the yield of compound B were also studied.The thermal property studies indicate that the mass loss of compound B was 54.39% at 242.2~750℃,and when the temperature was 1 000℃,there was 25.11% char residue left,which showed that the title compound has a good thermal stability and char forming capability.Using acetonitrile as the solvent instead of trichloromethane or 1,2-dichloethane gave higher yield.During the synthesis,the yield was very low when triethylamine was used as acid acceptor alone,and when a little amount of 4-dimethylaminopyridine (DMAP) was added at the same time,the yield could be 81%.
2007, 24(7): 835-837
Abstract:
(E)-3-(2-chlorophenyl)-1-(2,4-dichlorophenyl) prop-2-en-1-one was prepared from 2-chlorobenzal-dehyde followed by cyclization with hydrazine monohydrate.Eight new derivatives of 3-(2,4-dichlorophenyl)-5-(2-chlorophenyl)-4,5-dihydro-N-acylpyrazole were synthesized and characterized by elemental analysis,IR and 1H NMR.The experimental results show that the inhibition rates of compound 3f toward H.Oryzae and P.oryzae at 50 mg/L were 55.2% and 57.1%,respectively,and the inhibition rates of compound 3g toward H.Oryzae,P.oryza,and S.Sclerotiorum.at 50 mg/L were 52.3%,60.0% and 50.4%,respectively.
(E)-3-(2-chlorophenyl)-1-(2,4-dichlorophenyl) prop-2-en-1-one was prepared from 2-chlorobenzal-dehyde followed by cyclization with hydrazine monohydrate.Eight new derivatives of 3-(2,4-dichlorophenyl)-5-(2-chlorophenyl)-4,5-dihydro-N-acylpyrazole were synthesized and characterized by elemental analysis,IR and 1H NMR.The experimental results show that the inhibition rates of compound 3f toward H.Oryzae and P.oryzae at 50 mg/L were 55.2% and 57.1%,respectively,and the inhibition rates of compound 3g toward H.Oryzae,P.oryza,and S.Sclerotiorum.at 50 mg/L were 52.3%,60.0% and 50.4%,respectively.
2007, 24(7): 838-840
Abstract:
A new method of extracting and separating rutin in an aqueous two-phase system (ATPS) formed from water-soluble ionic liquid [Bmim] BF4 (1-butyl-3-methylimidazolium tetrafluoroborate) and phase-forming salt NaH2PO4 at room temperature was studied.The effect of concentrations of ionic liquid,salt added,rutin and solution acitity on the partition of rutin were investigated systematically.In a pH 2~7 ionic liquid-ATPS system of a total volume of 5 mL formed from 0.5~2.5 mL of 80% alcohol solution of rutin,1.0~2.5 mL [Bmim] BF4 and 1.0~2.0 g of NaH2PO4,the ionic liquid phase had the highest extraction efficiency of 90%.Moreover,a lot of foreign substances did not interfere with the phase ratio and the determination of rutin except for cationic surfactants.Compared to that for a ethanol-water solution,the maximum absorption wavelength of the rutin in ionic liquid shifts to lower wavelength,indicating the interaction of rutin and ionic liquid.This method can be applied to the determination of rutin in ginkgo leaves.
A new method of extracting and separating rutin in an aqueous two-phase system (ATPS) formed from water-soluble ionic liquid [Bmim] BF4 (1-butyl-3-methylimidazolium tetrafluoroborate) and phase-forming salt NaH2PO4 at room temperature was studied.The effect of concentrations of ionic liquid,salt added,rutin and solution acitity on the partition of rutin were investigated systematically.In a pH 2~7 ionic liquid-ATPS system of a total volume of 5 mL formed from 0.5~2.5 mL of 80% alcohol solution of rutin,1.0~2.5 mL [Bmim] BF4 and 1.0~2.0 g of NaH2PO4,the ionic liquid phase had the highest extraction efficiency of 90%.Moreover,a lot of foreign substances did not interfere with the phase ratio and the determination of rutin except for cationic surfactants.Compared to that for a ethanol-water solution,the maximum absorption wavelength of the rutin in ionic liquid shifts to lower wavelength,indicating the interaction of rutin and ionic liquid.This method can be applied to the determination of rutin in ginkgo leaves.
2007, 24(7): 841-843
Abstract:
To determine the Cu,Fe,Zn,K,and Na contents in Yin Zhi Huang injection and its four ingredients by FAAS,the samples were digested with concentrated nitric acid and hydrogen peroxide,and the experimental conditions such as wavelength,slit-width,lamp-current,air-acetylene discharge ratio,the height of burner and interference elimination reagent were optimized.2% HNO3,2% HCl and 6% CH3(CH2)3OH were respectively used as interference elimination reagents for Cu,K,Na,Fe and Zn.Thus,the interference was eliminated and the sensitivity was increased.The linear regression equations and the correlation coefficients were:ACu=0.087 4c+0.007 8,rCu=0.999 5;AZn=0.244 6c+0.072 4,rZn=0.999 6;AFe=0.065 9c+0.022 1,rFe=0.999 9;AK=0.224 2c+0.008 3,rK=0.999 5;ANa=0.613 0c+0.038 0,rNa=0.999 3.The recoveries of this method were in the range of 95.6%~111%,with a RSD' value of less than 4.0%.This method proved to be simple,rapid with high accuracy and satisfactory results,and it could provide basic data for the quality standard of Yin zhi huang injection.
To determine the Cu,Fe,Zn,K,and Na contents in Yin Zhi Huang injection and its four ingredients by FAAS,the samples were digested with concentrated nitric acid and hydrogen peroxide,and the experimental conditions such as wavelength,slit-width,lamp-current,air-acetylene discharge ratio,the height of burner and interference elimination reagent were optimized.2% HNO3,2% HCl and 6% CH3(CH2)3OH were respectively used as interference elimination reagents for Cu,K,Na,Fe and Zn.Thus,the interference was eliminated and the sensitivity was increased.The linear regression equations and the correlation coefficients were:ACu=0.087 4c+0.007 8,rCu=0.999 5;AZn=0.244 6c+0.072 4,rZn=0.999 6;AFe=0.065 9c+0.022 1,rFe=0.999 9;AK=0.224 2c+0.008 3,rK=0.999 5;ANa=0.613 0c+0.038 0,rNa=0.999 3.The recoveries of this method were in the range of 95.6%~111%,with a RSD' value of less than 4.0%.This method proved to be simple,rapid with high accuracy and satisfactory results,and it could provide basic data for the quality standard of Yin zhi huang injection.
2007, 24(7): 844-846
Abstract:
A novel method for the synthesis of 2,2',4,4'-tetra carboxylic acid biphenyl with p-methyl aniline as raw material is described in this article.Firstly,2-amino-5-methylbenzoic acid was prepared from p-methyl aniline in three steps with a yield of 61.5%.The process was optimized and the quantities of the reactants were reduced remarkably.Then,4,4'-dimethyl-2,2'-diphenylic acid was obtained by the coupling of diazonium which was made by the diazotization of 2-amino-5-methylbenzoic acid.The effect of molar ratio of NaOH to NH2OH·HCl on the yield was researched.It was found that the maximum yield of 4,4'-dimethyl-2,2'-diphenylic acid was 88% when the molar ratio was 1:1.Finally,the target product 2,2',4,4'-tetra carboxylic acid biphenyl was prepared from the oxidation of 4,4'-dimethyl-2,2'-diphenylic acid by KMnO4 in an alkaline solution.Total yield based on p-methyl aniline was 43.3%.The structure of the product was characterized by 1H NMR and IR (KBr).By using benzoic diazonium as a reactant,this synthetic route for tetra carboxylic biphenyl uses mild reaction condition,with high yields and good industrial application potential.
A novel method for the synthesis of 2,2',4,4'-tetra carboxylic acid biphenyl with p-methyl aniline as raw material is described in this article.Firstly,2-amino-5-methylbenzoic acid was prepared from p-methyl aniline in three steps with a yield of 61.5%.The process was optimized and the quantities of the reactants were reduced remarkably.Then,4,4'-dimethyl-2,2'-diphenylic acid was obtained by the coupling of diazonium which was made by the diazotization of 2-amino-5-methylbenzoic acid.The effect of molar ratio of NaOH to NH2OH·HCl on the yield was researched.It was found that the maximum yield of 4,4'-dimethyl-2,2'-diphenylic acid was 88% when the molar ratio was 1:1.Finally,the target product 2,2',4,4'-tetra carboxylic acid biphenyl was prepared from the oxidation of 4,4'-dimethyl-2,2'-diphenylic acid by KMnO4 in an alkaline solution.Total yield based on p-methyl aniline was 43.3%.The structure of the product was characterized by 1H NMR and IR (KBr).By using benzoic diazonium as a reactant,this synthetic route for tetra carboxylic biphenyl uses mild reaction condition,with high yields and good industrial application potential.
2007, 24(7): 847-849
Abstract:
The present paper describes a direct one-step synthesis of various benzimidazoles from primary alcohols and o-phenylenediamine with good yields using iodine as the catalyst.The influence of reaction conditions such as the ratio of I2 and K2CO3,and temperature was studied.The yield of 2-(o-chlorophenyl) benzi-midazole was 86% via method A under the optimized reaction conditions,which were 70℃,n(o-ClC6H4CH2OH):n(o-phenylenediamine):n(I2):n(K2CO3)=1.0:1.1:5.0:5.0,and 5 h.The yield of 2-(o-chlorophenyl) benzimidazole was 69% via method B.In our work primary alcohols were used as the starting material instead of acids or aldehydes in the reported procedures.The present method is relatively simple and the reaction condition is mild.It is a new method for preparing benzimidazoles.A possible reaction mechanism is proposed as well.
The present paper describes a direct one-step synthesis of various benzimidazoles from primary alcohols and o-phenylenediamine with good yields using iodine as the catalyst.The influence of reaction conditions such as the ratio of I2 and K2CO3,and temperature was studied.The yield of 2-(o-chlorophenyl) benzi-midazole was 86% via method A under the optimized reaction conditions,which were 70℃,n(o-ClC6H4CH2OH):n(o-phenylenediamine):n(I2):n(K2CO3)=1.0:1.1:5.0:5.0,and 5 h.The yield of 2-(o-chlorophenyl) benzimidazole was 69% via method B.In our work primary alcohols were used as the starting material instead of acids or aldehydes in the reported procedures.The present method is relatively simple and the reaction condition is mild.It is a new method for preparing benzimidazoles.A possible reaction mechanism is proposed as well.
2007, 24(7): 850-852
Abstract:
Cyanoacetamide is an important intermediate.This paper reports a new preparation method for N-substituded cyanoacetamides from cyanoacetic acid and N-substituded amine via DCC coupling.Into equal mole of cyanoacetic acid and amine in solvent was added dropwise equal mole of DCC,refluxed,and the end of the reaction was determined with TLC.The crude product was recrystallized or chromatographed with proper solvent to afford the product in yield of 52%~90% and ≥95% purity.The product was characterized by mp,IR and 1H NMR.This procedure is convenient and gives higher yield,and is suitable for the preparation of cyanoacetamides from different amines.
Cyanoacetamide is an important intermediate.This paper reports a new preparation method for N-substituded cyanoacetamides from cyanoacetic acid and N-substituded amine via DCC coupling.Into equal mole of cyanoacetic acid and amine in solvent was added dropwise equal mole of DCC,refluxed,and the end of the reaction was determined with TLC.The crude product was recrystallized or chromatographed with proper solvent to afford the product in yield of 52%~90% and ≥95% purity.The product was characterized by mp,IR and 1H NMR.This procedure is convenient and gives higher yield,and is suitable for the preparation of cyanoacetamides from different amines.
