Aminomethylation of Thiourea with Formaldehyde and Cyclic Amines
Three-component condensation of thiourea with equimolar amounts of formaldehyde and morpholine afforded N-(morpholin-4-ylmethyl) derivative, whereas analogous reaction with 2 equiv of formaldehyde and amine gave symmetrical N,N′-bis(morpholin-4-ylmethyl)thiourea. In the condensation of thiourea with piperidine and formaldehyde, only symmetrical N,N′-bis(piperidin-1-ylmethyl)thiourea was isolated, regardless of the reactant ratio.