摘要
本文以3,4-二氯苯胺为原料合成了3,4-二氯苯肼盐酸盐,再与乙酰乙酸乙酯环化,合成2-(3,4-二氯苯基)-2,4-二氢-5-甲基-3H-吡唑啉-3-酮。用红外光谱、熔点仪、高效液相色谱和核磁共振对产品进行了表征和检测。考察了盐酸用量、还原剂、反应温度、溶剂和后处理对转化率和纯度的影响。结果表明:选用氯化亚锡作还原剂,在低温和盐酸过量下有利于提高3,4-二氯苯肼盐酸盐的收率。选用V(乙醇)∶V(水)=6∶1为溶剂,75℃下反应4小时,以碳酸钠调节pH=7,2-(3,4-二氯苯基)-2,4-二氢-5-甲基-3H-吡唑啉-3-酮转化率为82.6%,熔点163～164℃,纯度达96%。
3,4-Dichlorophenylhydrazine hydrochloride was synthesized from 3,4-dichloroanilin,then 2-(3,4-dichlorophenyl)-2,4-dihydro-5-methyl-3H-pyrazol-3-one was prepared by cyclization of it with ethyl acetoacetate.Structures of products were characterized by elemental analysis,melting point,HPLC and 1H-NMR.The effects of amount of hydrochloric acid,reducing agents,reaction temperature,solvents and after treatment on the yield and purity of products were investigated.The yield of 3,4-dichloro phenylhydrazine hydrochloride was increased in the conditions of stannous chloride as reducing agent,low temperature and excess hydrochloric acid.With solvent V(ethanol):V(water)=6:1,reaction temperature 75℃,reaction time 4 hours and adjusting pH=7 with sodium carbonate,the yield of 2-(3,4-dichlorophenyl)-2,4-dihydro-5-methyl-3H-pyrazol-3-one was 82%,melting point 163～164℃,purity higher than 96%.
出处
《染料与染色》
CAS
2012年第1期40-42,47,共4页
Dyestuffs and Coloration
基金
广西青年科学基金(No:0991048)
关键词
苯胺
苯肼盐酸盐
吡唑啉酮
精细化工中间体
aniline
phenylhydrazine hydrochloride
pyrazolone
fine chemical intermediates
