Ethyl 2-oxocyclopentanecarboxylate → 2-(Cyclobutylmethyl-amino)-cyclopentanecarboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

2-Oxo-cyclopentanecarboxylic acid ethyl ester (0.24 mL, 1.64 mmol) and C-cyclobutyl-methylamine hydrochloride (0.20 g, 1.64 mmol) were dissolved in methanol (8 mL). Sodium acetate (0.27 g, 3.28 mmol) was added followed by 4 Å powdered molecular sieves (0.20 g) and sodium cyanoborohydride (0.21 g, 3.28 mmol). The reaction was stirred at 25° C. for 16 h. The mixture was poured into a mixture of saturated aqueous sodium bicarbonate solution (20 mL) and ethyl acetate (30 mL). After shaking, both layers were passed through a plug of Celite. The organic layer was further washed with saturated aqueous sodium bicarbonate solution (10 mL), saturated aqueous brine solution (10 mL), dried over magnesium sulfate, filtered, and concentrated in vacuo to afford the crude product, 2-(cyclobutylmethyl-amino)-cyclopentanecarboxylic acid ethyl ester (0.29 g, 1.30 mmol, 79%) as a clear oil. LC-MS (ESI) calcd for C13H23NO2 225.33, found 226.2 [M+H+].

Provenance & Evidence