Sodium Bicarbonate → (4S,9aS)-4-benzhydryl-8-benzyloxycarbonyl-2-[2-methoxy-5-[5-(trifluoromethyl)-1H-tetrazol-1-yl]benzyl]octahydro-2H-pyrazino[1,2-a]pyrazine

Participants

Reaction Steps

To a solution of 2-methoxy-5-[5-(trifluoromethyl)-1H-tetrazol-1-yl]benzaldehyde (582 mg) and (4S,9aS)-4-benzhydryl-8-(benzyloxycarbonyl)octahydro-2H-pyrazino[1,2-a]pyrazine dihydrochloride (1.0 g) in dichloromethane (10 ml) was added portionwise sodium tritacetoxyborohydride (824 mg) under ice-cooling, and then it was stirred at room temperature for 90 minutes. The mixture was poured into aqueous sodium hydrogen carbonate 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 (23 g) using a mixed solvent of hexane and ethyl acetate (2:1). The fractions containing the objective compound were collected and evaporated under reduced pressure to give (4S,9aS)-4-benzhydryl-8-benzyloxycarbonyl-2-[2-methoxy-5-[5-(trifluoromethyl)-1H-tetrazol-1-yl]benzyl]octahydro-2H-pyrazino[1,2-a]pyrazine (0.98 g) as a colorless foam.

Provenance & Evidence