反应详情

A mixture of 2.57 g of 1-bromocyclopropanecarboxylic acid 4 [H. M. R. Hoffmann et al. J. Org. Chem. 54, 6096 (1989)], 2.22 g of 1-amino-2-pentanone hydrochloride 5 [M. Jackman et al. J. Am. Chem. Soc. 70, 2884 (1948)] and 3.36 g of N,N′-dicyclohexylcarbodiimide in 234 ml of methylene chloride in the presence of 2.46 ml of triethylamine is stirred overnight at room temperature. Then, it is filtered, the filtrate is concentrated by evaporation, and the residue is chromatographed on silica gel with ethyl acetate/hexane. 2.74 g of 1-bromo-N-(2-oxopentyl)-cyclopropane-1-carbamide 6 is obtained as a crystallizing oil.

1. filtrationThen, it is filtered
2. concentrationthe filtrate is concentrated by evaporation
3. customthe residue is chromatographed on silica gel with ethyl acetate/hexane