The new title compound, chiral 2-(3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl)- 2-oxoethyl acetate, has been synthesized via reduction, cyclization and acylation reaction. The structure of the product has been conf...The new title compound, chiral 2-(3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl)- 2-oxoethyl acetate, has been synthesized via reduction, cyclization and acylation reaction. The structure of the product has been confirmed by IR, 1H NMR, 13C NMR, LC-MS (ESI) and single-crystal X-ray diffraction. (R)-2-(3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl)-2-oxoethyl acetate crystallizes in monoclinic, space group P21/c with a = 11.867(2), b = 8.4087(2), c = 14.325(6) A^°, β = 117.59(2)°, Z = 4, V = 1266.9(6) A^°3, Dc = 1.307 g/cm^3, F(000) = 528, μ(MoKα) = 0.097 mm-1, R = 0.0453 and wR = 0.1237; (S)-2-(3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl)-2-oxoethyl acetate belongs to the triclinic system, space group P with a = 8.2647(17), b = 8.7034(17), c = 9.5479(19) A^°, α = 105.33(3), β = 100.95(3), γ = 105.14(3)°, Z = 2, V = 614.1(2) A^°3, Dc = 1.348 g/cm^3, F(000) = 264, μ(MoKα) = 0.10 mm-1, R = 0.0613 and wR = 0.1037. Both of the molecules prefer to form crystal packing through C–H…O hydrogen bonds.展开更多
The title compound, acetic acid-3,5-diacetoxy-2-acetoxymethyl-6-(4-quinoxalin- 2-yl-phenoxy)-tetrahydro-pyran-4-yl-ester 8 (C28H28N2O10, Mr = 552.54), has been synthesized and its crystal structure was determined ...The title compound, acetic acid-3,5-diacetoxy-2-acetoxymethyl-6-(4-quinoxalin- 2-yl-phenoxy)-tetrahydro-pyran-4-yl-ester 8 (C28H28N2O10, Mr = 552.54), has been synthesized and its crystal structure was determined by X-ray diffraction analysis. It crystallizes in monoclinic, space group P21, a = 10.060(8), b = 5.648(4), c = 24.11(2)A, β = 91.078(10)°, Z = 2, V= 1369.9(19)A^3, Dc = 1.339 g/cm^3,μ(MoKa) = 1.03 cm^-1, F(000) = 580.00, T =. 193.1 Kx-9 θmax = 25.03, (△/σ)max = 0.0000, Flack = -0.0(24), the final R = 0.0680 and wR = 0.140 (w = 1/[0.0016Fo^2 + 1.00000(Fo^2)]/(4Fo^2)) for 3126 observed reflections (1 〉 20(/)). The pyranoid ring adopts chair conformation in the sugar moiety, and all of the acetyl groups are in the e bond of the pyranoid ring, so the sugar moiety is very stable.展开更多
Sodium 3,5-bis(hydroxyimino)-1-methyl-2,4,6-trioxocyclohexanide C7H5N2NaO5 (I) has been isolated as the only product of the reaction of nitrosation of methylphloroglucinol. The structure of the titled compound has bee...Sodium 3,5-bis(hydroxyimino)-1-methyl-2,4,6-trioxocyclohexanide C7H5N2NaO5 (I) has been isolated as the only product of the reaction of nitrosation of methylphloroglucinol. The structure of the titled compound has been determined from single crystal X-ray diffraction data. The hydrated C7H5N2NaO52.5H2O crystallizes in the monoclinic space group C2/c, with a(?) 16.408(3);b(?) 12.446(3);c(?) 13.716(3);(o) 126.34(3). The planar organic anion exists in a triketo-dihydroxyimino form with the C–O and C–N distances from 1.220(2) to 1.271(2)?? and from 1.292(2) to 1.293?? respectively. In the IR spectrum of I, the sharp absorption band occurred at 1681 cm-1 due to C=O stretching indicating the strong H-interactions. The correlations of theoretical (DFT-B3LYP/aug-cc-pVDZ) and experimental UV-vis absorption spectra in neutral and alkaline ethanolic solutions showed the existence of hydroxyimino-nitroso tautomerism while ionization of I.展开更多
基金supported by the National Natural Science Foundation of China(No.31572042)Natural Science Foundation of Heilongjiang Province(B201303)the Research Science Foundation in Technology Innovation of Harbin(No.2015RAYXJ010)
文摘The new title compound, chiral 2-(3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl)- 2-oxoethyl acetate, has been synthesized via reduction, cyclization and acylation reaction. The structure of the product has been confirmed by IR, 1H NMR, 13C NMR, LC-MS (ESI) and single-crystal X-ray diffraction. (R)-2-(3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl)-2-oxoethyl acetate crystallizes in monoclinic, space group P21/c with a = 11.867(2), b = 8.4087(2), c = 14.325(6) A^°, β = 117.59(2)°, Z = 4, V = 1266.9(6) A^°3, Dc = 1.307 g/cm^3, F(000) = 528, μ(MoKα) = 0.097 mm-1, R = 0.0453 and wR = 0.1237; (S)-2-(3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl)-2-oxoethyl acetate belongs to the triclinic system, space group P with a = 8.2647(17), b = 8.7034(17), c = 9.5479(19) A^°, α = 105.33(3), β = 100.95(3), γ = 105.14(3)°, Z = 2, V = 614.1(2) A^°3, Dc = 1.348 g/cm^3, F(000) = 264, μ(MoKα) = 0.10 mm-1, R = 0.0613 and wR = 0.1037. Both of the molecules prefer to form crystal packing through C–H…O hydrogen bonds.
基金This project was supported by the Key Laboratory of Organic Synthesis of Jiangsu Province
文摘The title compound, acetic acid-3,5-diacetoxy-2-acetoxymethyl-6-(4-quinoxalin- 2-yl-phenoxy)-tetrahydro-pyran-4-yl-ester 8 (C28H28N2O10, Mr = 552.54), has been synthesized and its crystal structure was determined by X-ray diffraction analysis. It crystallizes in monoclinic, space group P21, a = 10.060(8), b = 5.648(4), c = 24.11(2)A, β = 91.078(10)°, Z = 2, V= 1369.9(19)A^3, Dc = 1.339 g/cm^3,μ(MoKa) = 1.03 cm^-1, F(000) = 580.00, T =. 193.1 Kx-9 θmax = 25.03, (△/σ)max = 0.0000, Flack = -0.0(24), the final R = 0.0680 and wR = 0.140 (w = 1/[0.0016Fo^2 + 1.00000(Fo^2)]/(4Fo^2)) for 3126 observed reflections (1 〉 20(/)). The pyranoid ring adopts chair conformation in the sugar moiety, and all of the acetyl groups are in the e bond of the pyranoid ring, so the sugar moiety is very stable.
文摘Sodium 3,5-bis(hydroxyimino)-1-methyl-2,4,6-trioxocyclohexanide C7H5N2NaO5 (I) has been isolated as the only product of the reaction of nitrosation of methylphloroglucinol. The structure of the titled compound has been determined from single crystal X-ray diffraction data. The hydrated C7H5N2NaO52.5H2O crystallizes in the monoclinic space group C2/c, with a(?) 16.408(3);b(?) 12.446(3);c(?) 13.716(3);(o) 126.34(3). The planar organic anion exists in a triketo-dihydroxyimino form with the C–O and C–N distances from 1.220(2) to 1.271(2)?? and from 1.292(2) to 1.293?? respectively. In the IR spectrum of I, the sharp absorption band occurred at 1681 cm-1 due to C=O stretching indicating the strong H-interactions. The correlations of theoretical (DFT-B3LYP/aug-cc-pVDZ) and experimental UV-vis absorption spectra in neutral and alkaline ethanolic solutions showed the existence of hydroxyimino-nitroso tautomerism while ionization of I.