English

• 1. INTRODUCTION

  Herbicide safeners are special purpose compounds that protect crops from herbicides without reducing the herbicide activity on target weeds^[1]. The successful development and application of safeners provide an effective way to solve the problem of phytotoxicity and selectivity in the weed control process. Since the first safener, 1, 8-naphthalic anhydride, was introduced in 1971^{[2, 3]}, hundreds of compounds with protective activity have been developed, and more than 30 species have been commercialized^[4-6]. They have been widely used in crops such as maize^[7], soybean^[8], cereal^{[9, 10]} and so on to protect them from herbicides.

  It is of great significance to study the mechanism of safeners for the development of new safeners and to explore the physiological and biochemical selection mechanisms of herbicides^{[11, 12]}. According to the existing research results, the mechanism of safeners can be roughly attributed to the following four aspects: (1) Safeners can affect the activity of herbicide target enzymes; (2) Safener interfere with the absorption and conduction of herbicides; (3) Safeners promote the metabolism of herbicides in crops^[13]; (4) Competition between safeners and herbicide receptors and target sites^{[14, 15]}. The most widely accepted mechanism is that safeners enhance crop tolerance by inducing the expression of proteins involved in herbicide metabolism, thus accelerating their detoxification.

  As part of our ongoing synthesis of nitrogen-containing heterocyclic herbicide safeners^[16-19], two novel compounds have been synthesized by nucleophilic addition and FriedelCrafts acylation reactions. 5-Methyl-3-substituted phenylisoxazole-4-carboxylic acid, ethanolamine, and 3-methyl butanone or butanone were used as the starting materials. The substituted 1, 3-oxazolidine was synthesized by microwave assistant technology^[20-22], then the target compounds were synthesized by acylation of 5-methyl-3-phenylisoxazole-4-carbonyl chloride with the intermediates oxazolidine. The synthetic route of compounds 6a and 6b is shown in Scheme 1. The single-crystal structure was confirmed by X-ray diffraction analysis in order to further investigate the relationship between the substituted phenyl oxazole carboxamides isoxazole molecular structure and the bioactivity when chlorsulfuron was 2 μg/kg.

  Scheme 1

  

  Scheme 1.  Synthetic route of the compounds 6a and 6b

  DownLoad: Full-Size Img PowerPoint

  2. EXPERIMENTAL

  2.1 Materials and characterization

  All the solvents and reactants were analytical pure and applied without purification. The melting point was gauged on a Beijing Taike point instrument (X-4) and uncorrected. The IR spectra were collected on a Bruker ALPHA-T spectrometer (in KBr pallets). The NMR spectrum was collected on a Bruker AV-300 spectrometer using CDCl₃ as solvent and TMS as an internal standard. The high-resolution mass spectrum (HRMS) was collected on FTICR-MS. Crystallographic data of the compound were measured on a Rigaku R-AXIS RAPID area-detector diffractometer.

  2.2 Preparation of 5-methyl-3-phenylisoxazole-4-carbonyl chloride (2)

  5-Methyl-3-substituted phenylisoxazole-4-carboxylic acids 1 (40 mmol) and SOCl₂ (10 mL) were mixed in toluene (15 mL) and refluxed for 2 h at 70 ℃. After cooling to room temperature, the mixture was concentrated under vacuum to obtain 5-methyl-3-phenylisoxazole-4-carbonyl chloride 2 as yellow oil without purification.

  2.3 Preparation of the substituted 1, 3-oxazolidine (5)

  Ethanolamine 4 (36 mmol) and 3-methyl butanone (or butanone) 3 (30 mmol) were added in toluene (15 mL). The mixture was preheated for 6 min under microwave irradiation (33 ℃, 500 W). Then it was continued to be stirred for another 8 min (85 ℃, 800 W)^[23] to obtain the key intermediate compound 5.

  2.4 Preparation of substituted phenyl oxazole isoxazole carboxamides (6)

  The 5-methyl-3-phenylisoxazole-4-carbonyl chloride 2 (36 mmol) in 20 mL toluene was added dropwise to the 1, 3-oxazolidines 5 (30 mmol) with anhydrous K₂CO₃ as the attaching acid agent at 20~25 ℃, and the mixture was stirred for 2 h. When the progress was finished (TLC monitored), the reaction mixture was filtered, washed with water and concentrated. The residue was purified by column chromatography on silica gel using 1:1 (v/v) petroleum ether/EtOAc as eluent to obtain the target compounds 6.

  3-Phenyl-4-(2΄-methyl-2΄-isopropyl-1΄, 3΄-oxazole)-5-methyl isoxazole carboxamide (6a) White crystal; m.p. 113~114 ℃; yield, 21.4%; IR (KBr, cm^-1) ν: 2973~2872 (C–H), 1637 (C=O). ¹H NMR (300 MHz, CDCl₃, ppm) δ: 7.74~7.44 (m, 5H, Ar–H), 3.84~3.81, 3.64~3.60 (m, 2H, C–CH₂–O), 3.20~3.07 (m, 2H, N–CH₂–C), 2.89~2.82 (m, 1H, C–CH–C), 2.52 (s, 3H, CH₃–C–O), 1.63 (s, 3H, N–C–CH₃), 1.03~0.86 (dd, J = 48.0Hz, 6H, CH₃–C–CH₃). ¹³C NMR (75MHz, CDCl₃, ppm) δ: 168.45, 160.11, 159.30, 130.38, 129.04, 129.04, 128.60, 127.42, 127.42, 114.04, 99.45, 63.63, 48.00, 33.60, 20.62, 17.14, 16.63, 11.80. HRMS (ESI): C₁₈H₂₂N₂O₃ calcd. for [M+H]⁺ 315.1703, found 315.1695.

  3-(2΄-Fluoro-6΄-chloro-phenyl)-4-(2΄-methyl-2΄-ethyl-1΄, 3΄-oxazole)-5-methyl isoxazole carboxamide (6b) White crystal; m.p. 132~133 ℃; yield, 37.9%; IR (KBr, cm^-1) ν: 3088~2879 (C–H), 1645 (C=O). ¹H NMR (300 MHz, CDCl₃, ppm) δ: 7.38~7.06 (m, 3H, Ar–H), 3.90~3.81 (m, 2H, C–CH₂–O), 3.45~3.29 (m, 2H, N–CH₂–C), 2.56 (s, 3H, CH₃–C–O), 2.16~1.82 (m, 2H, C–CH₂–C), 1.49 (s, 3H, N–C–CH₃), 0.78~0.73 (t, J=9.0Hz, 3H, C–CH₃). ¹³C NMR (75MHz, CDCl₃, ppm) δ: 168.01, 162.45, 159.10, 153.89, 134.90, 132.07, 125.85, 117.10, 115.93, 114.68, 97.44, 63.46, 47.71, 29.58, 22.30, 12.47, 7.49. HRMS (ESI): C₁₇H₁₈ClFN₂O₃ calcd. for [M+H]⁺ 353.1069, found 353.1063.

  2.5 Crystal data and structure determination

  Crystals (6a and 6b) suitable for X-ray analysis were obtained by the slow evaporation method with EtOAc as the solvent at room temperature. The X-ray data were collected on a Rigaku RAXIS-RAPID diffractometer (Japan) with MoKα radiation (λ = 0.71073 Å) at 293(2) K. Crystal 6a with dimensions of 0.52mm × 0.48mm × 0.42mm crystallizes in monoclinic system, M_r = 314.38, total reflections collected in the range of 3.14≤θ≤25.00º, R_int = 0.0298, –7≤h≤7, –23≤k≤23 and –16≤l≤16. Crystal 6b (0.17mm × 0.13mm × 0.12mm) is of triclinic system, M_r = 352.78, total reflections collected in the range of 3.20≤θ≤24.99º, R_int = 0.0237, –8≤h≤9, –12≤k≤12 and –13≤l≤13.

  The structure was solved by direct method using SHELXS-97^[24] and refined with SHELXL-97^[25]. The hydrogen atoms were included in calculated positions, and refined in terms of riding model (U_iso(H) = 1.5U_eq(C) for the atoms of the methyl and U_iso(H) = 1.2U_eq(C) for others). Selected bond lengths and bond angles for compounds 6a and 6b are listed in Table 1, and hydrogen bond parameters are summarized in Table 2.

  Table 1

  

  Table 1.  Selected Bond Lengths (Å) and Bond Angles (°) for Crystals of 6a and 6b

  DownLoad: CSV

  6a			6b
  Bond	Dist.		Bond	Dist.
  C(1)–N(1)	1.312(2)		C(1)–F(1)	1.402(4)
  C(1)–C(2)	1.478(2)		C(5)–Cl(1)	1.699(3)
  C(8)–C(11)	1.502(2)		C(6)–C(7)	1.481(4)
  C(9)–O(1)	1.353(2)		C(7)–N(1)	1.312(4)
  C(9)–C(10)	1.483(3)		C(8)–C(11)	1.486(4)
  C(11)–O(2)	1.2289(18)		C(9)–O(1)	1.350(4)
  C(11)–N(2)	1.334(2)		C(9)–C(10)	1.485(4)
  C(12)–N(2)	1.461(2)		C(11)–O(2)	1.228(3)
  C(13)–O(3)	1.425(2)		C(11)–N(2)	1.346(4)
  C(14)–O(3)	1.422(2)		C(12)–N(2)	1.475(4)
  C(14)–N(2)	1.497(2)		C(13)–O(3)	1.428(5)
  C(14)–C(15)	1.522(2)		C(14)–O(3)	1.434(4)
  C(14)–C(16)	1.532(2)		C(14)–N(2)	1.488(4)
  N(1)–O(1)	1.408(2)		C(14)–C(16)	1.501(6)
  			C(14)–C(15)	1.547(6)
  			N(1)–O(1)	1.406(3)
  Angle	(°)		Angle	(°)
  N(1)–C(1)–C(8)	111.49(14)		C(2)–C(1)–F(1)	118.0(3)
  N(1)–C(1)–C(2)	119.68(15)		C(6)–C(1)–F(1)	118.8(3)
  C(8)–C(1)–C(2)	128.71(14)		C(4)–C(5)–Cl(1)	118.7(3)
  C(3)–C(2)–C(1)	120.89(15)		C(6)–C(5)–Cl(1)	119.1(2)
  C(7)–C(2)–C(1)	120.27(15)		C(1)–C(6)–C(7)	121.9(3)
  O(1)–C(9)–C(8)	109.31(15)		C(5)–C(6)–C(7)	122.5(3)
  O(1)–C(9)–C(10)	116.60(15)		N(1)–C(7)–C(8)	112.1(3)
  O(2)–C(11)–N(2)	124.14(14)		N(1)–C(7)–C(6)	119.4(3)
  O(2)–C(11)–C(8)	119.19(14)		C(8)–C(7)–C(6)	128.5(3)
  N(2)–C(11)–C(8)	116.67(13)		O(1)–C(9)–C(8)	109.1(3)
  N(2)–C(12)–C(13)	100.25(14)		O(1)–C(9)–C(10)	116.2(3)
  O(3)–C(13)–C(12)	103.51(14)		O(2)–C(11)–N(2)	122.5(3)
  O(3)–C(14)–N(2)	102.06(13)		O(2)–C(11)–C(8)	119.2(3)
  O(3)–C(14)–C(15)	110.28(14)		N(2)–C(11)–C(8)	118.3(2)
  N(2)–C(14)–C(15)	110.31(14)		N(2)–C(12)–C(13)	100.3(3)
  O(3)–C(14)–C(16)	108.27(13)		O(3)–C(13)–C(12)	104.2(3)
  N(2)–C(14)–C(16)	112.11(13)		O(3)–C(14)–N(2)	101.6(3)
  C(1)–N(1)–O(1)	105.42(14)		O(3)–C(14)–C(16)	108.4(3)
  C(11)–N(2)–C(12)	125.30(13)		N(2)–C(14)–C(16)	113.1(3)
  C(11)–N(2)–C(14)	124.21(12)		O(3)–C(14)–C(15)	110.2(3)
  C(12)–N(2)–C(14)	110.16(13)		N(2)–C(14)–C(15)	111.1(3)
  C(9)–O(1)–N(1)	109.10(12)		C(7)–N(1)–O(1)	104.8(2)
  C(14)–O(3)–C(13)	107.97(13)		C(11)–N(2)–C(12)	126.2(3)
  			C(11)–N(2)–C(14)	122.3(2)
  			C(12)–N(2)–C(14)	110.7(3)
  			C(9)–O(1)–N(1)	109.6(2)
  			C(13)–O(3)–C(14)	107.4(3)

  Table 2

  

  Table 2.  Hydrogen Bond Parameters in Structures of 6a and 6b

  DownLoad: CSV

  D–H···A	d(D–H)	d(H···A)	d(D···A)	∠DHA
  C(12)–H(12A)···O(2)a C(3)–H(3)···O(2)b C(10)–H(10A)···O(2)c	0.97 0.93 0.96	2.56 2.54 2.54	3.49 3.2175(60) 3.4630(21)	162 130 170
  Symmetry codes: (a) 1+x, y, z; (b) 1–x, 1–y, 2–z; (c) 1–x, 1–y, 1–z

  3. RESULTS AND DISCUSSION

  The molecular structures of compounds 6a and 6b with atom-numbering are shown in Fig. 1. The crystal structure 6a crystallizes in monoclinic space group P2₁/c, and 6b crystallizes in the triclinic space group P$ \overline 1 $.

  Figure 1

  

  Figure 1.  Molecular diagram of compounds 6a and 6b

  DownLoad: Full-Size Img PowerPoint

  Both of the crystal structures consist of three rings: a five-membered isoxazole ring (A), a benzene ring (B) and a five-membered oxazole ring (C). For compound 6a, the molecule is not coplanar because the dihedral angles between rings A, B and C are 38.64° (A/B), 82.31° (A/C) and 83.99° (B/C), indicating rings A and B are almost perpendicular to ring C. For compound 6b, the molecule is also not coplanar because the dihedral angles between rings A, B and C are 61.19° (A/B), 70.19° (A/C) and 69.82° (B/C), but no perpendicular conformation is found. The bond distance of C(6)–C(7) (1.481(4) Å) is shorter than the typical C–C distance (1.54 Å)^[26] in compound 6b, which results from the π-π conjugated system between the benzene rings (Fig. 2). However, there is no π-π conjugated system in compound 6a. The possible reason lies in the steric hindrance of fluorine and chlorine atoms.

  Figure 2

  

  Figure 2.  Showing the π-π stacking interactions of 6b

  DownLoad: Full-Size Img PowerPoint

  Hydrogen bonding interactions play a significant role in the crystal packing of 6a and 6b. Crystal structure 6a forms crystal packing via hydrogen bonds C(12)–H(12A)···O(2), and the crystal packing of 6b is via the C(3)–H(3)···O(2) and C(10)–H(10A)···O(2) hydrogen bonds, as shown in Fig. 3. The presence of hydrogen bonds causes the target compounds to arrange in an ordered manner and form a single crystal structure with high symmetry and regularity.

  Figure 3

  

  Figure 3.  Molecular packing diagram of 6a and 6b. Hydrogen bonds are described as dashed lines

  DownLoad: Full-Size Img PowerPoint

  4. BIOLOGICAL ACTIVITIES

  The title compounds were evaluated for the recovery rate of various growth indicators of maize against the injury of chlorsulfuron being 2 μg/kg. The root fresh weight recovery rates of 6a, 6b and isoxadifen ethyl are 33.55%, 36.94% and 41.99%, respectively. The root length recovery rate of compound 6a is 36.59%, which is close to that of the safeners isoxadifen ethyl (46.38%). However, the corresponding value of compound 6b is only 12.12%, much lower than that of compound 6a.

  The bioassay results showed that compounds 6a and 6b showed detoxification effect on maize and could restore maize growth. But there are differences in detoxification effect, the main reason for which is that the introduction of electron with drawing group (F and Cl atoms) at benzene ring, which leads to the decreased activity of the compound.

  
  
• 1. [1]

     Riechers, D. E.; Kreuz, K.; Zhang, Q. Detoxification without intoxication: herbicide safeners activate plant defense gene expression. Plant Physiol. 2010, 153, 3−13. doi: 10.1104/pp.110.153601

  2. [2]

     Taylor, V. L.; Cummins, I.; Brazier-Hicks, M.; Edwards, R. Protective responses induced by herbicide safeners in wheat. Environ. Exp. Bot. 2013, 88, 93−99. doi: 10.1016/j.envexpbot.2011.12.030

  3. [3]

     Davies, J.; Caseley, J. C. Herbicide safeners: a review. Pestic. Sci. 1999, 55, 1043−1058. doi: 10.1002/(SICI)1096-9063(199911)55:11<1043::AID-PS60>3.0.CO;2-L

  4. [4]

     Bernasinska, J.; Duchnowicz, P.; Koter-Michalak, M.; Koceva-Chyla, A. Effect of safeners on damage of human erythrocytes treated with chloroacetamide herbicides. Environ. Toxicol. Pharmacol. 2013, 36, 368−377. doi: 10.1016/j.etap.2013.04.010

  5. [5]

     Davies, J. Herbicide safeners-commercial products and tools for agrochemical research. Pestic Outlook 2001, 12, 10−15. doi: 10.1039/b100799h

  6. [6]

     Samsidar, A.; Siddiquee, S.; Shaarani, S. M. A review of extraction, analytical and advanced methods for determination of pesticides in environment and foodstuffs. Trends Food Sci. Technol. 2017, 71, 188−201.

  7. [7]

     Ye, F.; Zhai, Y.; Guo, K. L.; Liu, Y. X.; Li, N.; Gao, S.; Zhao, L. X.; Fu, Y. Safeners improve maize tolerance under herbicide toxicity stress by increasing the activity of enzymes in Vivo. J. Agric. Food Chem. 2019, 67, 11568−11576. doi: 10.1021/acs.jafc.9b03587

  8. [8]

     Ni, Y.; Yang, H.; Zhang, H.; He, Q.; Huang, S.; Qin, M.; Chai, S.; Gao, H.; Ma, Y. Analysis of four sulfonylurea herbicides in cereals using modified quick, easy, cheap, effective, rugged, and safe sample preparation method coupled with liquid chromatography-tandem mass spectrometry. J. Chromatogr. A 2018, 1537, 27−34. doi: 10.1016/j.chroma.2018.01.017

  9. [9]

     Gao, S.; Jiang, J. Y.; Li, X. M.; Liu, Y. Y.; Zhao, L. X.; Fu, Y.; Ye, F. Enhanced physicochemical properties and herbicidal activity of an environment-friendly clathrate formed by β-cyclodextrin and herbicide cyanazine. J. Mol. Liq. 2020, 305, 112858. doi: 10.1016/j.molliq.2020.112858

  10. [10]

      Cheng, L.; Zhang, R. R.; Wu, H. K.; Liu, X. H.; Xu, T. M. The synthesis of 6-(tert-butyl)-8-fluoro-2, 3-dimethylquinoline carbonate derivatives and their antifungal activity against pyricularia oryzae. Front. Chem. Sci. Eng. 2019, 13, 369−376. doi: 10.1007/s11705-018-1734-7

  11. [11]

      Fu, Y.; Zhang, D.; Zhang, S. Q.; Liu, Y. X.; Guo, Y. Y.; Wang, M. X.; Gao, S.; Zhao, L. X.; Ye, F. Discovery of N-aroyl diketone/triketone derivatives as novel 4-hydroxyphenylpyruvate dioxygenase inhibiting-based herbicides. J. Agric. Food Chem. 2019, 67, 11839−11847. doi: 10.1021/acs.jafc.9b01412

  12. [12]

      Liu, X. H.; Zhao, W.; Shen, Z. H.; Xing, J. H.; Yuan, J.; Yang, G.; Xu, T. M.; Peng, W. L. Synthesis, nematocidal activity and docking study of novel chiral 1-(3-chloropyridin-2-yl)-3-(trifluoromethyl)-1H-pyrazole-4-carboxamide derivatives. Bioorg. Med. Chem. Lett. 2016, 26, 3626−3628. doi: 10.1016/j.bmcl.2016.06.004

  13. [13]

      Rowe, L. J. Efficacy and mode of action of CGA-15428, a protectant for corn(zea mays) from metolachlor injury. Weed Sci. 1991, 39, 78−82. doi: 10.1017/S004317450005791X

  14. [14]

      Yun, M. S.; Shim, S. I.; Usui, K. Involvement of cytochrome P450 enzyme activity in the selectivity and safening action of pyrazosulfuronethyl. Pest. Manag. Sci. 200l, 57, 283−288. doi: 10.1002/ps.298

  15. [15]

      Liu, X. H.; Fang, Y. M.; Xie, F.; Zhang, R. R.; Shen, Z. H.; Tan, C. X.; Weng, J. Q.; Xu, T. M.; Huang, H. Y. Synthesis and in vivo fungicidal activity of some new quinoline derivatives against rice blast. Pest. Manag. Sci. 2017, 73, 1900−1907. doi: 10.1002/ps.4556

  16. [16]

      Fu, Y.; Zhang, S. Q.; Liu, Y. X.; Wang, J. Y.; Gao, S.; Zhao, L. X.; Ye, F. Design, synthesis, SAR and molecular docking of novel green niacintriketone HPPD inhibitor. Ind. Crop. Prod. 2019, 137, 566−575. doi: 10.1016/j.indcrop.2019.05.070

  17. [17]

      Zhang, Y. Y.; Gao, S.; Liu, Y. X.; Wang, C.; Zhao, L. X.; Fu, Y.; Ye, F., Design, synthesis and biological activity of novel diazabicyclo derivatives as safeners. J. Agric. Food Chem. 2020, 68, 3403−3414. doi: 10.1021/acs.jafc.9b07449

  18. [18]

      Fu, Y.; Wang, K.; Wang, P.; Kang, J. X.; Gao, S.; Zhao, L. X.; Ye, F. Design, synthesis and herbicidal activity evaluation of novel aryl-naphthyl methanone derivatives. Front. Chem. 2019, 7, 2. doi: 10.3389/fchem.2019.00002

  19. [19]

      Ye, F.; Ma, P.; Zhang, Y. Y.; Li, P.; Yang, F.; Fu, Y. Herbicidal activity and molecular docking study of novel accase inhibitors. Front. Plant Sci. 2018, 9, 1850. doi: 10.3389/fpls.2018.01850

  20. [20]

      Shen, Z. H.; Sun, Z. H.; Becnel, J. J.; Estep, A.; Wedge, D. E.; Tan, C. X.; Weng, J. Q.; Han, L.; Liu, X. H. Synthesis and mosquiticidal activity of novel hydrazone containing pyrimidine derivatives against aedes aegypti. Lett. Drug Des. Discov. 2018, 15, 951−956. doi: 10.2174/1570180815666180102141640

  21. [21]

      Liu, X. H.; Qiao, L.; Zhai, Z. W.; Cai, P. P.; Cantrell, C. L.; Tan, C. X.; Weng, J. Q.; Han, L.; Wu, H. K. Novel 4-pyrazole carboxamide derivatives containing flexible chain motif: design, synthesis and antifungal activity. Pest. Manag. Sci. 2019, 75, 2892−2900. doi: 10.1002/ps.5463

  22. [22]

      Gao, S.; Liu, Y. Y.; Jiang, J. Y.; Li, X. M.; Zhao, L. X.; Fu, Y.; Ye, F. Encapsulation of thiabendazole in hydroxypropyl-beta-cyclodextrin nanofibers via polymer-free electrospinning and its characterization. Pest Manag. Sci. 2020, 76, 3264−3272. doi: 10.1002/ps.5885

  23. [23]

      Ye, F.; Zhai, Y.; Kang, T.; Wu, S. L.; Li, J. J.; Gao, S.; Zhao, L. X.; Fu, Y. Rational design, synthesis and structure-activity relationship of novel substituted oxazole isoxazole carboxamides as herbicide safener. Pest. Biochem. Physiol. 2019, 157, 60−68. doi: 10.1016/j.pestbp.2019.03.003

  24. [24]

      Sheldrick, G. M. SHELXS-97, Program for X-ray Crystal Structure Solution. University of Göttingen, Germany 1997.

  25. [25]

      Sheldrick, G. M. SHELXS-97, Program for X-ray Crystal Structure Refinement. University of Göttingen, Germany 1997.

  26. [26]

      Xing, Q. Y.; Pei, W. W.; Xu, R. Q.; Pei, J. Fundamental organic chemistry. Third Edition. Higher Education Press, China 2005, p17−18.

• 

  Scheme 1  Synthetic route of the compounds 6a and 6b

  下载: 全尺寸图片 幻灯片
  

  Figure 1  Molecular diagram of compounds 6a and 6b

  下载: 全尺寸图片 幻灯片
  

  Figure 2  Showing the π-π stacking interactions of 6b

  下载: 全尺寸图片 幻灯片
  

  Figure 3  Molecular packing diagram of 6a and 6b. Hydrogen bonds are described as dashed lines

  下载: 全尺寸图片 幻灯片

  Table 1.  Selected Bond Lengths (Å) and Bond Angles (°) for Crystals of 6a and 6b

  6a			6b
  Bond	Dist.		Bond	Dist.
  C(1)–N(1)	1.312(2)		C(1)–F(1)	1.402(4)
  C(1)–C(2)	1.478(2)		C(5)–Cl(1)	1.699(3)
  C(8)–C(11)	1.502(2)		C(6)–C(7)	1.481(4)
  C(9)–O(1)	1.353(2)		C(7)–N(1)	1.312(4)
  C(9)–C(10)	1.483(3)		C(8)–C(11)	1.486(4)
  C(11)–O(2)	1.2289(18)		C(9)–O(1)	1.350(4)
  C(11)–N(2)	1.334(2)		C(9)–C(10)	1.485(4)
  C(12)–N(2)	1.461(2)		C(11)–O(2)	1.228(3)
  C(13)–O(3)	1.425(2)		C(11)–N(2)	1.346(4)
  C(14)–O(3)	1.422(2)		C(12)–N(2)	1.475(4)
  C(14)–N(2)	1.497(2)		C(13)–O(3)	1.428(5)
  C(14)–C(15)	1.522(2)		C(14)–O(3)	1.434(4)
  C(14)–C(16)	1.532(2)		C(14)–N(2)	1.488(4)
  N(1)–O(1)	1.408(2)		C(14)–C(16)	1.501(6)
  			C(14)–C(15)	1.547(6)
  			N(1)–O(1)	1.406(3)
  Angle	(°)		Angle	(°)
  N(1)–C(1)–C(8)	111.49(14)		C(2)–C(1)–F(1)	118.0(3)
  N(1)–C(1)–C(2)	119.68(15)		C(6)–C(1)–F(1)	118.8(3)
  C(8)–C(1)–C(2)	128.71(14)		C(4)–C(5)–Cl(1)	118.7(3)
  C(3)–C(2)–C(1)	120.89(15)		C(6)–C(5)–Cl(1)	119.1(2)
  C(7)–C(2)–C(1)	120.27(15)		C(1)–C(6)–C(7)	121.9(3)
  O(1)–C(9)–C(8)	109.31(15)		C(5)–C(6)–C(7)	122.5(3)
  O(1)–C(9)–C(10)	116.60(15)		N(1)–C(7)–C(8)	112.1(3)
  O(2)–C(11)–N(2)	124.14(14)		N(1)–C(7)–C(6)	119.4(3)
  O(2)–C(11)–C(8)	119.19(14)		C(8)–C(7)–C(6)	128.5(3)
  N(2)–C(11)–C(8)	116.67(13)		O(1)–C(9)–C(8)	109.1(3)
  N(2)–C(12)–C(13)	100.25(14)		O(1)–C(9)–C(10)	116.2(3)
  O(3)–C(13)–C(12)	103.51(14)		O(2)–C(11)–N(2)	122.5(3)
  O(3)–C(14)–N(2)	102.06(13)		O(2)–C(11)–C(8)	119.2(3)
  O(3)–C(14)–C(15)	110.28(14)		N(2)–C(11)–C(8)	118.3(2)
  N(2)–C(14)–C(15)	110.31(14)		N(2)–C(12)–C(13)	100.3(3)
  O(3)–C(14)–C(16)	108.27(13)		O(3)–C(13)–C(12)	104.2(3)
  N(2)–C(14)–C(16)	112.11(13)		O(3)–C(14)–N(2)	101.6(3)
  C(1)–N(1)–O(1)	105.42(14)		O(3)–C(14)–C(16)	108.4(3)
  C(11)–N(2)–C(12)	125.30(13)		N(2)–C(14)–C(16)	113.1(3)
  C(11)–N(2)–C(14)	124.21(12)		O(3)–C(14)–C(15)	110.2(3)
  C(12)–N(2)–C(14)	110.16(13)		N(2)–C(14)–C(15)	111.1(3)
  C(9)–O(1)–N(1)	109.10(12)		C(7)–N(1)–O(1)	104.8(2)
  C(14)–O(3)–C(13)	107.97(13)		C(11)–N(2)–C(12)	126.2(3)
  			C(11)–N(2)–C(14)	122.3(2)
  			C(12)–N(2)–C(14)	110.7(3)
  			C(9)–O(1)–N(1)	109.6(2)
  			C(13)–O(3)–C(14)	107.4(3)

  下载: 导出CSV

  Table 2.  Hydrogen Bond Parameters in Structures of 6a and 6b

  D–H···A	d(D–H)	d(H···A)	d(D···A)	∠DHA
  C(12)–H(12A)···O(2)a C(3)–H(3)···O(2)b C(10)–H(10A)···O(2)c	0.97 0.93 0.96	2.56 2.54 2.54	3.49 3.2175(60) 3.4630(21)	162 130 170
  Symmetry codes: (a) 1+x, y, z; (b) 1–x, 1–y, 2–z; (c) 1–x, 1–y, 1–z

  下载: 导出CSV
•