Kinetics of desulphuration of ethylthiourea in sodium hydroxide studied by a radiochromatographic method

Abstract

Decomposition of ethylthiourea in aqueous sodium hydroxide has been studied by a radiochromatographic method. The main process is second-order desulphuration, EtNHCSNH₂+ OH^–→ C₂H₅NHCN + HS^–+ H₂O, but a small amount of thiocyanate is formed as a by-product. Rate constants at 90, 100, and 110° and derived activation parameters have been obtained. Possible mechanisms are discussed taking into account the fact that desulphuration is three times faster for thiourea than for ethylthiourea, under the same conditions.