C(Cl)(=O)C(Cl)=O.CS(C)=O.[CH2:11]([O:18][C:19]([NH:21][CH2:22][CH:23]([OH:26])[CH2:24][CH3:25])=[O:20])[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1.C(N(CC)CC)C>C(Cl)Cl>[CH2:11]([O:18][C:19]([NH:21][CH2:22][C:23](=[O:26])[CH2:24][CH3:25])=[O:20])[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1
To methylene chloride (60 mL) at -78° C. under argon was added oxalyl chloride (37 mL of 2 M solution in methylene chloride, 74 mmol), followed by DMSO (7.8 g, 100 mmol). The mixture was stirred at 78° C. for 20 min. and to this mixture was added a solution of 1-benzyloxycarbonylamino-2-butanol (13.9 g, 61.8 mmol) in methylene chloride (40 mL). The mixture was stirred at -78° C. for 1 h and triethylamine (21 mL) was added to the mixture. It was warmed to room temperature (rt) and washed successively with 1 N hydrochloric acid and aqueous sodium bicarbonate solution. The methylene chloride solution was dried over MgSO4 and concentrated to afford 1-benzyloxycarbonylamino-2-butanone (11.2 g, 82%) as a solid, which was enough pure for the next reaction. 1H NMR (CDCl3) δ7.32 (m, 5 H), 5.50 (s, 1 H), 5.06 (s, 2 H), 4.07 (s, 2 H), 2.43 (q, J=7.6 Hz, 2 H), 1.06 (t, J=7.6 Hz, 3 H).
Wird geladen…
