Dimethylformamide → N,N'-Dicyclohexylurea

Participants

Reaction Steps

Into 100 ml of dimethylformamide, 23.8 g of Compound (A), 30.1 g of Compound (B) and 0.8 g of 4-dimethylamino-pyridine were dissolved, and thereto an ethyl acetate 20 ml solution containing 20.6 g of dicyclohexylcarbodiimide was added dropwise in an ice bath. After the dropwise addition, the solution was allowed to react at room temperature over night. Into the reaction solution, 200 ml of ethyl acetate was poured, and dicyclohexylurea obtained was separated by filtration. Into the filtrate, 300 ml of water was poured to perform liquid separation operation. Water washing was performed twice, the organic layer was dried over anhydrous magnesium sulfate, the solvent was distilled off under reduced pressure, and the oily product obtained was subjected to silica gel column chromatography. As a result, from the methylene chloride/ethyl acetate=10/3 fraction, 43 g of Compound (C) was obtained as a pale yellow oily product. ##STR16## Synthesis of Compound (D):

Provenance & Evidence