反应详情

Oxalyl chloride (0.208 ml) was added dropwise to a suspension prepared by adding 390 mg of 6-carboxy-1-(2-chlorobenzyl)-2-cyclopropylbenzimidazole to 10 ml of methylene chloride containing 1 drop of N,N-dimethylformamide at room temperature over a period of several minutes. The mixture was stirred at the same temperature for 2 hours, and was then concentrated under reduced pressure. Isopropyl ether was added to the residue, and the mixture was pulverized to give 450 mg of 1-(2-chlorobenzyl)-6-chlorocarbonyl-2-cyclopropylbenzimidazole hydrochloride (60) as a white powder. Since this product was unstable, it was used as a starting material in the subsequent step without being purified.

1. customprepared
2. concentrationwas then concentrated under reduced pressure
3. additionIsopropyl ether was added to the residue