1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → Benzyl 3-(2-hydroxy-3-(methoxycarbonyl)phenylcarbamoyl)azetidine-1-carboxylate

Participants

Reaction Steps

To a solution of 1-(benzyloxycarbonyl)azetidine-3-carboxylic acid (2.4 g) in dichloride methane (15 ml) was added 1-hydroxybenzotriazole (1.48 mg, 11 mmol), diisopropylethylamine (4 g, 30 mmol) and 1-ethly-3-(3-dimethylaminopropyl)carbodiimide hydrochloric (2 g, 11 mmol). The mixture was stirred at room temperature for 30 min. Then ethyl 3-amino-2-hydroxybenzoate (700 mg, 4 mmol) was added. The mixture was stirred at room temperature for 2 h. To the resulting mixture, water (10 ml) was added and hydrochloride acid (1N) to pH=3, then extracted with ethyl acetate (100 ml×4). The organic phase was washed with sodium bicarbonate (saturated) and brine and concentrated, dried with sodium sulfate. The crude was purified by column chromatography (silica gel, petroleum ether/ethyl acetate=20:1). 820 mg of benzyl 3-(2-hydroxy-3-(methoxycarbonyl)phenylcarbamoyl)azetidine-1-carboxylate was obtained. Yield 52%. LC-MS (ESI) m/z: 385 (M+1)+.

Provenance & Evidence