Hydrochloric Acid → Tert-butyl(+/-)-4-(1-amino-3-methylbutyl)benzoate

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 4-(3-methylbutanoyl)benzoate (500 mg, 1.91 mmol) and ammonium acetate (1.50 g, 19.1 mmol) in methanol (9.5 mL) was added sodium cyanoborohydride (189 mg, 2.86 mmol). The mixture was heated to 60° C. for 21 hours, then cooled to room temperature. 1 N hydrochloric acid (7 mL) was added dropwise. After 1 hour, the mixture was concentrated under reduced pressure to remove methanol. 1 N sodium hydroxide (10 mL) was added, and the mixture was extracted with dichloromethane (3×25 mL). The combined organics were washed with sat. aq sodium chloride (15 mL), dried over anhydrous Na2SO4, and filtered, and the filtrate was concentrated. Purification by silica gel flash chromatography (methanol/dichloromethane) gave tert-butyl (+/−)-4-(1-amino-3-methylbutyl)benzoate as a colorless oil. 1H NMR (400 MHz, CDCl3) δ 7.99-7.94 (m, 2 H), 7.41-7.37 (m, 2 H), 4.08-4.01 (m, 1 H), 1.60 (s, 9 H), 1.59-1.43 (m, 3 H), 0.92 (d, J=6.5 Hz, 3 H), 0.90 (d, J=6.3 Hz, 3 H).

Provenance & Evidence