Thionyl Chloride → 2-Chloro-4-methyl-1,3-thiazole-5-sulfonyl chloride

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Reaction Steps

At room temperature, 150 g (1.12 mol) of 2-chloro-4-methyl-1,3-thiazole are added dropwise to a solution of 331 g (2.81 mol) of thionyl chloride in 653 g (5.61 mol) of chlorosulphonic acid. The solution is heated at reflux for 48 h. The mixture is then poured into 3 l of ice-water and extracted with 4×400 ml of dichloromethane. The combined organic phases are washed with 2.5 l of water, dried over sodium sulphate and concentrated. Distillation of the crude product gives 233.7 g of product in the form of an oil. (Bp 87-96° C., 0.7 mbar, GC 98.1%, yield 89.6%).

Provenance & Evidence