Production of S-substituted isothioureas

摘要

A process for the production of an S-substituted isothiourea including the functional group <IMAGE> in which R1 is an alkyl, alkenyl, aryl or aralkyl radical, comprising reacting a thiourea including the functional group <IMAGE> with an alpha-activated etherifying agent of the formula X-A-Y in which X is a halogen atom, A is a direct bond or CH2, and Y is an electron withdrawing group, thereby to produce the ether <IMAGE> and in a second step reacting the ether with a compound of the formula R1SH. The process is particularly applicable to the production of the known herbicide <IMAGE> from the corresponding thiourea where in the first step chloroacetic acid is used to form the S- carboxymethyl isothiourea which is then interchanged with ethyl mercaptan. Higher overall yields and/or economies are thereby achieved.