Synthesis And Condition Optimization Of 3-Hydroxy-4-methylbenzonitrile

3-hydroxy-4-methylbenzonitrile is an important intermediate of organic drugs,and no synthesis of 3-hydroxy-4-methyl phenylmethylcyanide has been reported in China.In this paper,P-tolunitrile as raw materials,mixed acid nitration obtained after the product 3-nitro-4-methylbenzonitrile.3-amino-4-methylbenzonitrile was obtained by hydrazine hydrate,and 10%FeO(OH)/C was used as catalyst in the reduction process.The target product 3-hydroxy-4-methylbenzonitrile was obtained by the Diazotization-hydrolysis reaction of 3-amino-4-methylphenylnitrile.The products and intermediates are characterized by FT-IR and 1H-NMR.The following conclusions are obtained:The nitrification method is determined by mixed acid nitration by the comparison experiment;The optimal reaction conditions of the nitrification method by orthogonal experiment are as follows: The ratio of raw material and nitric acid is 1: 1.2,sulfuric acid is 80 g,The reaction temperature is-10? and the reaction time is 6 hours;The yield of the optimum conditions for mixed acid nitration is 86.55%;The reduction method is hydrazine hydrate reduction determined by comparative experiments.The optimal conditions for hydrazine hydrate reduction are as follows:The ratio of raw material and hydrazine hydrate is 1: 2.4,the mass of catalyst is 1g,the reaction temperature is 80?,the reaction time is 3 hours;the yield of reduction optimum conditions for hydrazine hydrate is 79.64%;The optimal conditions for diazotization-hydrolysis reaction are as follows: The ratio of raw material and 50% sulfuric acid is 1: 3.5;The volume of toluene is 5 mL;the reaction temperature is 110 ?,and the reaction time is 40 min.The best yield of diazotization-hydrolysis is 77.23%.The total conversion of 3-hydroxy-4-methylbenzonitrile is 53.23%.