Method for producing 5-methyl benzotriazole

This invention relates to a production method of 5-methyl benzotriazole. Its characteristic is that it includes following steps: (1)in reaction kettle, put 3,4 diaminotoluene in purified water, heat to dissolve; (2)add sodium nitrite of 3,4 diaminotoluene in the solution that is produced by step (1), progress reaction; (3)cool the solution produced by step (2); (4)drop sulphuric acid in the solution produced by step (3), appear a great quantity of crystal; (5)progress manipulation that takes off the liquid for mixture produced by step (4); (6) heat the crystal produced by step (5), dewater; (7)distill the crystal produced by step (6), produce the stated 5-methyl benzotriazole. The production method of this invention uses 3,4 diaminotoluene as raw material, through medium voltage synthesis, acidification, dehydration, distilling manipulation, to prepare 5-methyl benzotriazole. Technology is simple, preparation process is easy to control, yield is high, purity is high, production cost is low, and it is easy to organize industrialized production.