Abstract N-Bromosuccinimide reacts with o-tolyl isothiocyanate to afford 2- isothiocyanatobenzyl bromide, a new type of bifunctional synthon. Nucleophiles I-, SCN-, 4- CH 3 C 6 H 4 SO 2-and hexamethylenetetramine yield substitution products of bromine. Amines and phenols react exclusively with the NCS grouping under formation of unstable thioureas, which in turn cyclize to the corresponding 4H-benzo [d][1, 3] thiazines. Structure ...