Benzaldehyde → 2-acetamido-2-(1-benzylpiperidin-4-yl)-N-tert-butyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanamide

Participants

Reaction Steps

A solution of 2-acetamido-N-tert-butyl-2-(piperidin-4-yl)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanamide (480 mg, 1.10 mmol) and benzaldehyde (138 mg, 131 jut, 1.30 mmol) in 1,2-dichloroethane (1 mL) was stirred for 20 minutes then treated with sodium triacetoxyborohydride (420 mg, 2.20 mmol). After 5 hours, the reaction mixture was quenched with saturated aqueous sodium bicarbonate (10 mL), diluted with saturated aqueous sodium chloride (50 mL) and extracted with dichloromethane (3×40 mL). Organic layers were collected, dried over MgSO4, filtered and concentrated. MPLC purification (25 g column, 1-10% methanol in dichloromethane) gave 2-acetamido-2-(1-benzylpiperidin-4-yl)-N-tert-butyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanamide as a colorless oil (538 mg, 93%), which was used immediately in the subsequent step (approximately 10% of the product had the boronic acid deprotected).

Provenance & Evidence