Isopropyl chloroformate → N-[5,8-dihydro-2-(4-formyl-1-piperazinyl)-5-oxopyrido[2,3-d]pyrimidine-6-carbonyloxy]succinimide

Participants

Reaction Steps

A suspension of 5,8-dihydro-2-(4-formyl-1-piperazinyl)-5-oxopyrido[2,3-d]pyrimidine-6-carboxylic acid (273 g) and triethylamine (299 ml) in dried dichloromethane (3500 ml) was stirred well at room temperature for one hour. To the suspension, isopropyl chloroformate (221 g) was added dropwise with cooling at 0°-10° C. and the reaction mixture was stirred for 2 hours. A solution of N-hydroxysuccinimide (207 g) in dimethylformamide (350 ml) was added to the mixture and the resulting mixture was kept at 5°-10° C. for an additional 2 hours. The crystalline product was collected by filtration and washed successively with water (2000 ml) and acetone (2000 ml) to give N-[5,8-dihydro-2-(4-formyl-1-piperazinyl)-5-oxopyrido[2,3-d]pyrimidine-6-carbonyloxy]succinimide (326 g). m.p. above 300° C.

Provenance & Evidence