2-Chlorobenzoxazole → Tert-butyl 4-[1-(1,3-benzoxazol-2-yl)-2-methoxy-2-oxoethyl]benzoate

反応式

[CH3:1][O:2][C:3](=[O:18])[CH2:4][C:5]1[CH:17]=[CH:16][C:8]([C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])=[CH:7][CH:6]=1.C[Si]([N-][Si](C)(C)C)(C)C.[Na+].Cl[C:30]1[O:31][C:32]2[CH:38]=[CH:37][CH:36]=[CH:35][C:33]=2[N:34]=1>C1COCC1>[O:31]1[C:32]2[CH:38]=[CH:37][CH:36]=[CH:35][C:33]=2[N:34]=[C:30]1[CH:4]([C:5]1[CH:17]=[CH:16][C:8]([C:9]([O:11][C:12]([CH3:14])([CH3:15])[CH3:13])=[O:10])=[CH:7][CH:6]=1)[C:3]([O:2][CH3:1])=[O:18]

参加物

実験手順

A solution of tert-butyl 4-(2-methoxy-2-oxoethyl)benzoate (0.6 g, 2.4 mmol) in THF (10 mL) was cooled to −78° C. and treated with sodium bis(trimethylsilyl)amide (0.44 g, 2.4 mmol) and stirred at this temperature for 15 minutes. To this solution was added 2-chlorobenzoxazole (2.4 mmol, 2.4 mL of a 1.0M solution). The reaction was warmed to ambient temperature and stirred for 16 hours. The reaction was evaporated and purified by flash chromatography (0-15% ethyl acetate/hexanes) to give tert-butyl 4-[1-(1,3-benzoxazol-2-yl)-2-methoxy-2-oxoethyl]benzoate as a yellow oil. 1H NMR (600 MHz, DMSO-d6) δ 7.91 (d, J=8.21 Hz, 2H), 7.71 (m, 2H), 7.60 (d, J=8.21 Hz, 2H), 7.37 (m, 2H), 5.94 (s, 1H), 3.70 (s, 3H), 1.51 (s, 9H); ESIMS calcd 368.1 (M++H), found 368.1 (M++H).