Dimethylformamide → Methyl 2-chloro-1,3-benzoxazole-7-carboxylate

反応式

[CH3:1][O:2][C:3]([C:5]1[C:13]2[O:12][C:11](S)=[N:10][C:9]=2[CH:8]=[CH:7][CH:6]=1)=[O:4].S(Cl)([Cl:17])=O.CN(C=O)C>>[CH3:1][O:2][C:3]([C:5]1[C:13]2[O:12][C:11]([Cl:17])=[N:10][C:9]=2[CH:8]=[CH:7][CH:6]=1)=[O:4]

参加物

反応物 3

HCID 6228Dimethylformamide

HCID 24386Thionyl Chloride

HCID 178497587HCID 178497587、化合物

生成物 1

HCID 68406054Methyl 2-chloro-1,3-benzoxazole-7-carboxylate収率 81%

実験手順

To 2-mercapto-benzooxazole-7-carboxylic acid methyl ester (1.0 g, 4.78 mmol, 1.0 equiv) was added thionyl chloride (8.0 g, 4.9 mL, 67.6 mmol, 14.0 equiv) and anhydrous DMF (0.4 g, 0.4 mL, 5.19 mmol, 1.1 equiv) and the reaction mixture heated to reflux for 15 min. The solvent was removed under reduced pressure, the crude oil azeotroped twice with xylene and the crude material purified with column chromatography on silica eluting with ethyl acetate/hexane (1:1) to afford 0.81 g (81%) of the title compound. 1H NMR (300 MHz, CDCl3): δ 4.03 (s, 3H), 7.44 (t, J=7.9 Hz, 1H), 7.87 (dd, J=7.9 Hz, J=1.1 Hz, 1H), 8.01 (dd, J=7.9 Hz, J=1.1 Hz, 1H). 13C NMR (75 MHz, CDCl3): δ 52.46, 115.07, 124.36, 124.82, 127.54, 142.39, 150.35, 152.24, 163.88. MS (ISP): 212.0 [M+H]+.