Evidence is presented to indicate that the condensation of aromatic thiols, formaldehyde, and aromatic amines in the presence of strong acid results first in the formation of the intermediate products, N-arylaminomethyl aryl sulfides (I) which then rearrange intermolecularly to p-aminobenzyl aryl sulfides (11), a process resembling closely the acid- catalyzed rearrangement of diazoaminobenzenes to p-aminoazobenzenes, Two ...