Isobutyl chloroformate → HCID 54284655, compound

Participants

Reaction Conditions

Reaction Steps

A solution of (R)-(+)-piperidine-1,2-dicarboxylic acid 1-tert-butyl ester (1.00 g, 4.4 mmol) in dry tetrahydrofuran (9.6 mL) was cooled to 0° C. and treated with diisopropylethylamine (0.95 g, 1.3 mL) and isobutyl chloroformate (0.89 g, 0.86 mL, 6.5 mmol). A white suspension formed, which was stirred at 0° C. for 4 h. The mixture was then diluted with acetonitrile (6.6 mL) until a clear solution was obtained. A cooled (0° C.) solution of trimethylsilyl diazomethane (2N in hexanes, 4.4 mL, 8.7 mmol) in dry tetrahydrofuran (3 mL) and acetonitrile (3 mL) was added to the reaction mixture during 3 min. The mixture was then stirred at 0° C. for 3 h, and at room temperature for 16 h. The volatiles were evaporated and the residue purified by flash chromatography (heptane/ethyl acetate gradient) to yield 2-(2-diazo-acetyl)-piperidine-1-carboxylic acid tert-butyl ester as a yellow oil (0.26 g, 23%), MS (ISP): 254.14 (M+H)+..

Provenance & Evidence