2-Thiazolylhydrazine and all three thiazole carbonyl peroxides have been synthesized and examined as radical precursors in solution in benzene, bromobenzene, and cumene. Silver oxide oxidation of the hydrazine or thermal decomposition of the 2-peroxide gives good yields of 2-arylthiazoles but negligible amounts of esters; in cumene a trace of bicumyl is formed. The isomer ratios in bromobenzene and cumene fully support the involvement of ...