摘要
以水合肼、尿素和苯甲醛为原料 ,一锅法合成苯甲醛缩氨基脲 ,该工艺中间产物氨基脲不以氨基脲盐酸盐形式分离 ,直接与苯甲醛进行缩合反应 ,且不产生含肼废水。适宜的反应条件为 :n (H2 NNH2 ·H2 O)∶n (H2 NCONH2 )∶n (C6H5CHO) =1 0∶2 0∶0 8,氨基脲合成反应温度 98～ 10 1℃ ,反应时间 3～ 4h ;缩合反应pH =3～ 4 ,滴加时间 1 5h ,室温搅拌 2h ,回流 1h ,产物收率为 98.0 %。
Benzaldehyde semicarbazone was prepared from hydrazine hydrate,urea and benzaldehyde by one pot synthesis .According to this process, the intermediate semicarbazide was not isolated from the reaction mixture as semicarbazide HCl but directly reacted with benzaldehyde to give semicarbazone,and the waste liquid containing hydrazine was not formed.Thus, at optimum operation conditions, hydrazine hydrate(50%),urea and benzaldehyde in mole ratio 1 0∶2 0∶0 8 were used,hydrazine hydrate and ure reacted at 98-101 ℃for 3-4 h to form semicarbazide, then,at pH 3-4 and room temperature,benzaldehyde was dropped in during 1.5h,the mixture was further stirred for 2h and finally refluxed for 1h. Yield of the semicarbazone was 98.0%.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2002年第2期112-113,117,共3页
Fine Chemicals
