PROCESS FOR THE PREPARATION OF 3-DIHALOBENZYL-2,4-QUINAZOLINEDIONE DERIVATIVES

摘要

A process for preparing 3-dihalobenzyl-2,4-quinazolinedione derivatives of general formula (V) (wherein X<1>, X<2>, and X<3> are each halogeno; and A is alkylene) by reacting a dihalobenzyl derivative of general formula (III) (wherein L is an acid residue; and X<2> and X<3> are each as defined above) with a carboxylalkylated 2,4-quinazolinedione derivative of general formula (I) (wherein X<1> and A are each as defined above) to selectively replace the imino hydrogen atom of the derivative (I). The above process enables the efficient preparation of the compounds of general formula (V) useful as inhibitors against aldose reductases, makes it possible to secure the safety and hygiene of workers, and can facilitate waste disposal to reduce the expenses, thus being industrially extremely advantageous.