（1School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China;
2Shandong Weifang Kemai Chemical Coporation, Weifang 262700, China）
Abstract The synthesis of adipic acid dihydrazide by two steps was investigated in this paper. Adipic acid was first esterified with methanol under the catalysis of KHSO4 to give dimethyl adipate, which was further reacted with hydrazine hydrate to produce adipic acid dihydrazide (ADH) with a high purity. The optimal conditions for the esterification reaction were determined as catalyst amount was 5.5% of the weight amount of adipic acid, molar ratio of methanol to adipic acid was 4.0, reaction time was 1.0 h. Under these conditions, the purity of dimethyl adipate was as high as 998% and the yield was 77%. For the hydrazide reaction, the optimal conditions were: molar ratio of both hydrazine hydrate and methanol to dimethyl adipate was 4.0, reaction time was 1.5 h. Under these conditions, the yield of adipic acid dihydrazide reached 99% and the purity was 99.5%.
2014, Vol. 31 
