抗球虫药常山酮中间体7-溴-6-氯-4(3H)-喹唑啉酮的合成

7-溴-6-氯-4(3H)-喹唑啉酮是合成抗球虫药物常山酮的重要中间体。作者以硝基苯为起始原料,经溴化、还原、缩合、环化等7步反应,合成了题示物,总收率60%。在n(硝基苯)∶n(硫酸)∶n(溴酸钠)=1∶10∶1,硫酸质量分数为64%,反应温度为25℃,反应时间为1.5 h时,产率为95%。作者通过改变起始原料,降低了合成成本,使反应条件温和,为常山酮及其衍生物的合成提供了新的思路。

Synthesis of Anticoccidial Drug Halofuginone Intermediate of 7-Bromo-6-chloro-4(3H)-quinazolinone

7-Bromo-6-chloro-4(3H)-quinazolinone is an important intermediate of anticoccidial drug halofuginone,which was prepared from nitrobenzene by bromination,reduction,condensation,cyclization etc..The overall yield of the seven-step process is 60%.The optimum technology conditions of bromination was n(nitrobenzene):n(H_2SO_4):n(sodium bromate)=1:10:1,w(H_2SO_4)=64%,reaction temperature 25 ℃,reaction time 1.5 h,the yield 95%.The raw material was changed in order to reduce the cost of synthesis,which was cuted down and the synthetic condition was mild.This method is widely applicable to the synthesis of halofuginone and its derivatives.