Collect. Czech. Chem. Commun. 1980, 45, 263-268

Reactions of thiourea with chloro- and bromoacetic acids

Jaromír Kaválek, Said El-Bahaie and Vojeslav Štěrba

Organic Chemistry Department, Institute of Chemical Technology, 532 10 Pardubice


The reaction of chloroacetic acid with thiourea represents an SN2 substitution of chlorine by sulphur atom and is about two orders of magnitude slower than that of bromoacetic acid. Chloroacetate ion reacts slower than chloroacetic acid only about 30%. The acid catalyzed splitting off of hydroxyl group from the formed tetrahedral intermediate is rate-limiting in the cyclization of the S-carboxylatomethyleneisothiouronium salt, formation of the intermediate being rate-limiting below pH 2.