FIELD: organic chemistry. SUBSTANCE: proposed method involves interaction of 2-nitroaniline with 2-hydroxytoluene, thus prepared 2-nitro-2′-hydroxy-5′-methylazobenzene is affected by reduction cyclization which is followed by recrystallization of desired product of organic solvent. Reprecipitation of desired product and vacuum distillation of high boiling oil (having vapor pressure not more 7 mm Hg at temperature not more 235 C) additionally take places after reduction cyclization. Said reprecipitation is carried out of alkaline solution (concentration of alkaline metal in it being not less 0.4 %) in the presence of activated coal (its concentration being not more 0.05 kg per 1 kg of product). Reduction cyclization is carried out with the help of hydrogen in binary solvent in the presence of highly dispersed heterogeneous catalyst and cocatalyst, ratio of 2-nitro-2′-hydroxy-5′-methylazobenzene, catalyst, cocatalyst and solvent being 1: 0.15-0.20:0.04-0.08:4.0-9.0 respectively. Raney nickel or Raney nickel being promoted by titanium (ratio of nickel and titanium being 1:0.15-0.25) is used as said heterogeneous catalyst. Lower alcohol and water (alcohol content in it being 0.25-0.4 weight parts) is used as said binary solvent, hydroxide of alkaline metal being used as said cocatalyst. Reduction cyclization takes place at pressure 1-15 atm, temperature being gradually increased from 40 C to 75 C at rate not more 2 C/min. Recrystallization is carried out in the presence of activated coal, its quantity being not more 0.05 kg per 1 kg of the product. EFFECT: improved efficiency of the method; increased yield of desired product; optically pure product is obtained; decreased amount of sewage and industrial slime. 2 tbl
