A Convenient Method for the Preparation of Primary and Symmetrical N,N′-Disubstituted Thioureas

All articles of this category A convenient process for the preparation of both primary thioureas 2 and symmetrical N , N ′-disubstituted thioureas 6 based on the condensation of amine hydrohalides 5 with potassium thiocyanate has been developed. This approach tolerates sterically bulky primary amine substrates (both chiral and achiral), and the products can usually be isolated by a simple filtration of the reaction mixture. This method is an especially attractive alternative for the synthesis of thioureas when the corresponding isothiocyanates are unavailable, or difficult to prepare. It is also worth noting that a wide variety of amine hydrohalides, which are used in this procedure, are commercially available. primary thioureas - symmetrical thioureas - potassium thiocyanate - amine hydrohalide