【摘要】 以水合肼和亚磷酸二甲酯为起始原料合成甲基肼,再直接和硫氰酸铵反应两步制取2-甲基氨基硫脲。详细研究并得到两步反应的优化条件:甲基化反应以四丁基溴化铵为催化剂,反应温度为110-120℃,反应时间为2h;后一步反应原料配比n(甲基肼)∶n(硫氰酸铵)=1∶1.2,热重排温度为120℃左右,热重排时间为2h。在此条件下总收率达45.5%(以水合肼计)。更多还原

【Abstract】 2-methylthiosemicarbazide was synthesized via two steps. Methyl hydrazine was synthesized from hydrazine and dimethyl phosphite,and then directly reacted with ammonium thiocyanate to obtain the target material. The optimal conditions were obtained as follows: methylated reaction was carried out in the presence of n-Bu4NBr as catalyst,the reaction temperature 110~120 ℃,and reaction time 2 h. The molar ratio of methyl hydrazine to ammonium thiocyanate was 1 ∶ 1.2 in the next step,the heat rearrangement temperature 120 ℃,and the time 2 h. The total yield of 2-methyl-thiosemicarbazide was 45.5% based on hydrazine.更多还原