PRODUCTION OF 3-METHYL-4-NITROPHENOL

PURPOSE:To improve selectivity and yield in short time, by carrying out the reaction of 3-methylphenol with a nitrous acid salt in the presence of a sulfuric acid when 3-methylphenol is reacted with the nitrous acid to provide the titled compound which is a raw material of compound useful as an organic phosphorus insecticide having low toxicity. CONSTITUTION:3-Methylphenol is reacted with a nitrous acid salt in the presence of sulfuric acid at -30-50 deg.C, preferably, -20-30 deg.C to provide the aimed compound which is a raw material of 0,0-dialkyl-3-(3-methyl-4-nitrophenol) thiophoshate useful as an insecticide. The sulfuric acid is used in concentration of range of 20-100%, especially preferably 50-100% and in an amount of 1-20 times weight range based on 3-methylphenol which is a raw material and preferably charged by dropping it into a mixed system of 3-methylphenol and nitrous acid salt. The nitrous acid salt (preferably sodium nitrite) is used in an amount of 1-5 times mol based on 3-methylphenol.