反应详情

Under nitrogen atmosphere, to a solution of (2R)-2-formylpiperazine-1,4-dicarboxylic acid 4-benzyl ester 1-tert-butyl ester (2.64 g) and 3-(2-methoxybenzylamino)-1,1-diphenylpropan-2-one (3.66 g) in dichloromethane (30 ml) was added acetic acid (0.607 ml) and sodium tritacetoxyborohydride (4.82 g) under ice-cooling, and then it was stirred at room temperature for 3 hours. The reaction mixture was poured into aqueous sodium hydrogen carbonate (100 ml) and extracted with dichloromethane. The organic layer was washed with brine, dried over sodium sulfate, and evaporated under reduced pressure. The resulting residue was purified by column chromatography on silica gel (82 g) using a mixed solvent of hexane and ethyl acetate (3:1). The fractions containing the objective compound were collected and evaporated under reduced pressure to give (2S)-2-[[N-(2-methoxybenzyl)-N-(2-oxo-3,3-diphenylpropyl)amino]methyl]piperazine-1,4-dicarboxylic acid 4-benzyl ester 1-tert-butyl ester (3.24 g) as a syrup.

1. temperaturecooling
2. extractionextracted with dichloromethane
3. washThe organic layer was washed with brine
4. dry with materialdried over sodium sulfate
5. customevaporated under reduced pressure
6. customThe resulting residue was purified by column chromatography on silica gel (82 g)
7. additionThe fractions containing the objective compound
8. customwere collected
9. customevaporated under reduced pressure