Abstract
Radical bromination of 4,5-dimethylthiazole 1 with different stoichiometries of N-bromosuccinimide in the presence of 2,2'-azobisisobutyronitrile afforded regioselectively mono-, tri- and tetra-bromo compounds 2, 5 and 6 in good yields while the dibromo derivatives 3 and 4 were formed without any apparent selectivity. Computational approaches are developed in order to rationalize the observed regiochemistry, showing that the whole reaction process involves some regioselectivity. (C) 2000 Elsevier Science B.V. All rights reserved.