Dimethylformamide → tert-Butyl 4-carbamoyl-4-isopropylpiperidine-1-carboxylate

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Reaction Steps

To a solution of 1-(tert-butoxycarbonyl)-4-isopropylpiperidine-4-carboxylic acid (500 mg, 1.843 mmol) in dichloromethane (5 ml) were added oxalyl chloride (2.76 ml, 5.53 mmol) and a drop (ca. 10 μl) of dimethylformamide. After stirring 1 h at room temperature, the mixture was concentrated and then dissolved in tetrahydrofuran (5 ml). Concentrated ammonium hydroxide (5 ml, 36.0 mmol) was added and the mixture was stirred overnight at room temperature, and then concentrated to a small volume, poured into 50 ml of 1 M NaOH, and diluted with 50 ml of ethyl acetate. The phases were separated, the aqueous was extracted with 2×25 ml of ethyl acetate, and then the combined organics were washed with 25 ml of brine, dried (Na2SO4), and concentrated to provide the title compound (411 mg, 1.520 mmol, 82% yield). Mass spectrum (ESI) 174.0 (M-Boc).

Provenance & Evidence