Hydrochloric Acid → 2-Chloro-4,5-bis-(p-methoxyphenyl)-thiazole

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Reaction Steps

10 g of the 1,2-bis-(p-methoxyphenyl)-2-isothiocyanoethanone so obtained are suspended in 150 ml of diethyl ether and, while stirring, the suspension is cooled to 15°-20°. Gaseous hydrogen chloride is then introduced slowly at such a rate that the reaction temperature does not exceed 20°. After about 45 minutes a clear, yellowish solution is obtained. It is maintained at 15° and a little hydrogen chloride is introduced for a further 7 hours, the solution is left to stand overnight at 15°, poured onto 300 ml of ice, the diethyl ether is removed by distillation, and the crystalline precipitate is filtered with suction, then washed twice with water and sucked dry on a suction filter. The crude product is recrystallised from 100 ml of hexane. 2-Chloro-4,5-bis-(p-methoxyphenyl)-thiazole having a melting point of 92°-94° is obtained.

Provenance & Evidence