Hydrochloric Acid → HCID 20211588, compound

Participants

Reaction Conditions

Reaction Steps

152 g (0.4 mol) of 2-(2-hydroxy-3-α-phenylethyl-5-methylphenyl)-6-chloro-benztriazole-1 oxide and 17.6 g (0.44 mol) of sodium hydroxide are introduced into 327 g of diethylene glycol dimethyl ether and the mixture is heated to 130° C, a little water distilling off azeotropically with the solvent. Exactly 12.0 g (0.24 mol) of hydrazine hydrate are passed in under the surface of the solution over the course of 11/2 hours while keeping the temperature between 133° and 135° C. In the course thereof, the water liberated is continuously removed by azeotropic distillation. After the addition is complete, the mixture is left to complete the reaction for about 1 hour at the same temperature and, as soon as the evolution of nitrogen stops, the resulting solution is cooled to 80° C and treated with 200 ml of cold water. About 53.7 g of 30% strength hydrochloric acid are then added dropwise at a regular rate until the mixture has a neutral reaction and it is cooled to about 40° C while stirring vigorously, whereupon the product crystallises out. The suspension is then diluted with 800 ml of water and filtered and the crude product is washed with a total of 300 ml of hot water. After drying in vacuo at 60°-70° C, 137.5 g of 2-(2-hydroxy-3-α-phenylethyl-5-methylphenyl)-5-chloro-benztriazole of 97% purity are obtained, which corresponds to a yield of 91.5% of theory. The melting point is 113°-115° C (the pure product melts between 115° and 119° C).

Provenance & Evidence