用邻氰基氯苄的副产物合成盐酸肼屈嗪的研究

用生产邻氰基氯苄的副产物w(邻氰基甲苯)=10%、w(邻氰基氯苄)=30%和w(邻氰二氯苄)=50%]合成了盐酸肼屈嗪,探讨了反应温度、反应时间及投料比对邻氰基苯甲醛和盐酸肼屈嗪收率的影响。最佳合成条件:1)将邻氰基氯苄的副产物在引发剂作用下于150～155℃深度氯化,产物中邻氰二氯苄质量分数大于85%;2)n(邻氰二氯苄):n(甲醇钠)=1:2.05,回流反应20h,制得缩醛;3)n(缩醛):n(盐酸)=1:3.9,在0℃酸解反应3h,得到邻氰基苯甲醛,收率90.5%;4)n(邻氰基苯甲醛):n(85%的水合肼)=1:3.5,pH=3,回流时间8h,盐酸肼屈嗪收率75%。

SYNTHESIS OF HYDRALAZINE HYDROCHLORIDE WITH BY PRODUCTS IN MANUFACTURE OF o-CYANOBENZYLCHLORIDE

Hydralazine hydroehloride was synthesized from the by-products, containing o-cyanotolu- ene, o-cyanobenzylchloride and o-cyanobenzalchloride with the mass percentage of 10%,30% and 50%, respectively, generated from the manufacture of o-cyanobenzylchloride. The effects of reaction temperature and time and ratios of raw materials on the yield of o-cyanobenzaldehyde and hydralazine hydrochloride were investigated. The procedures and optimal conditions were found as follows:First- ly, the by-product reacted with chlorine at 150-155℃,in the presence of initiator,to give o-cyano- benzalchloride with purity of above 85% Secondly, o-cyanobenzalchloride and sodium methoxide, in molar ratio of 1:2.05, were refluxed for 20 h to produce the corresponding acetal;Thirdly,the pre- pared acetal was hydrolyzed with HC1, in n(acetal):n(HCl)=1:3.9, at 0℃for 3 h to obtain o- cyanobenzaldehyde with the yield of 90.5% Finally, hydralazine hydrochloride was synthesized with the yield of 75% by refluxing o-cyanobenzaldehyde and hydrazine for 8 h at the molar ratio of 1:3.5 in the presence of HC1 and methanol.