tert-Butyl N-allyl-N-[2-(methoxy(methyl)amino)-2-oxo-ethyl]carbamate → tert-Butyl N-allyl-N-[2-oxo-2-(2-thienyl)ethyl]carbamate
Reaction equation
[CH2:1]([N:4]([CH2:12][C:13](N(OC)C)=[O:14])[C:5](=[O:11])[O:6][C:7]([CH3:10])([CH3:9])[CH3:8])[CH:2]=[CH2:3].[S:19]1[CH:23]=[CH:22][CH:21]=[C:20]1[Li]>O1CCCC1>[CH2:1]([N:4]([CH2:12][C:13](=[O:14])[C:20]1[S:19][CH:23]=[CH:22][CH:21]=1)[C:5](=[O:11])[O:6][C:7]([CH3:8])([CH3:9])[CH3:10])[CH:2]=[CH2:3]Participants
4
Procedure
To a solution of tert-butyl N-allyl-N-[2-(methoxy(methyl)amino)-2-oxo-ethyl]carbamate (25 g, 96.8 mmol) in tetrahydrofuran (339 mL) at −78° C. is added drop wise 2-thienyllithium (145 ml, 1 M in tetrahydrofuran) over 20 min. The reaction is carefully quenched with aqueous ammonium chloride (20 mL), diluted with water (100 mL), and extracted with dichloromethane. The organic layers are combined, dried over sodium sulfate, filtered, and concentrated to give a residue. The residue is purified by silica gel flash chromatography, eluting with hexane/ethyl acetate (1:0) to hexane/ethyl acetate (5:1) to give the title compound (15.2 g, 56%). ES/MS (m/e): 182 (M+H-100).