The method of preparation of o-methylphenol

The present invention discloses a method of preparation of o-methyl phenol, comprising the steps of: diazonium salt solution (1) was prepared; (2) hydrolysis reaction kettle, adding an organic solvent, under reflux conditions, with stirring, a solution of the diazonium salt solution addition was completed, the reaction was refluxed for 4-7 min, cooled to 50 ℃, allowed to stand and the organic layer was separated spent acid; (3) 5% solution of sodium hydroxide or sodium carbonate, the organic layer was neutralized to pH 5 1-6, layer of water, the organic layer was distilled at atmospheric pressure to a temperature of 186 deg.] C to the liquid phase, recovery of the solvent, removing light components, and then distilled at atmospheric pressure to collect 186 ℃ ~ 190 ℃ distillate product, i.e. raffinate heavies; crystallization spent acid, sodium sulfate was removed for reuse. The method of the present invention, high product yield, has reached 89%; the amount of sulfuric acid required in the reaction system is less than 30% of the original, reducing the amount of waste acid; reduces energy consumption, little spent acid tar, without decoking can be recycled and reused, crystalline sodium sulfate from the prior art color brown to white, significantly improved the quality.