Hydrochloric Acid → Thiazole, 2-chloro-5-(2-chloroethyl)-4-methyl-

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Reaction Conditions

Reaction Steps

A suspension of 177.6 g (1 mole) of 2-hydroxy-4-methyl-5-(2-chloroethyl)-thiazole in 530 cm3 of anhydrous chlorobenzene is heated to 100° C. under stirring. 306.6 g (2 moles) of phosphoryl chloride are flown into the solution in 30 minutes, then it is stirred at a temperature of 125°-130° C. until the formation of hydrogen chloride ceases (about 2 hours). The reaction mixture is cooled to 20° C., then it is poured onto 1.5 kg of ice. The phases are separated, the aqueous phase is extracted twice with 200 cm3 of chlorobenzene each. The combined phases containing the chlorobenzene are washed acid-free with water and then with a 5% sodium hydrogen carbonate solution and then evaporated under reduced pressure. The brown residue is fractionated in vacuo. 145 g (74%) of 2-chloro-4-methyl-5-(2-chloroethyl)-thiazole are obtained. The boiling point is 102° C. at a pressure of 53.2 Pa, n20D =1.5512, n30D =1.5468

Provenance & Evidence