Benzylamine → tert-butyl 5-(benzylamino)-4-methylhexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate

Participants

Reaction Steps

A solution of tert-butyl 4-methyl-5-oxohexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate (10.7 g, 44.7 mmol) and benzyl amine (7.67 g, 71.5 mmol) in 1,2-dichloroethane (250 mL) was stirred at room temperature for 2 h. Anhydrous magnesium sulfate (20 g, 166 mmol) was added. The resultant suspension was stirred at room temperature for additional 2 h. Sodium triacetoxyborohydride (18.95 g, 89 mmol) was added. After 60 h at room temperature, the mixture was quenched with saturated sodium bicarbonate (100 mL) and extracted with ethyl acetate (3×150 mL). The combined organic extracts were washed with water, brine, dried (MgSO4) and concentrated. Silica gel chromatography, eluting with 0-8% methanol in dichloromethane, gave tert-butyl 5-(benzylamino)-4-methylhexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate as a mixture of stereoisomers (13.2 g), which was taken to the next reaction without separation.

Provenance & Evidence