The major metabolites of the physiologically active compound dimethylthiourea (DMTU), dimethylaminoiminomethansesulfinic acid (DMAIMSA), and dimethylaminoiminomethanesulfonic acid (DMAIMSOA) were synthesized, and their kinetics and mechanisms of oxidation by acidic bromate and aqueous bromine was determined. The oxidation of DMAIMSA is much more facile and rapid as compared to a comparable oxidation by the same reagents of the parent compound, DMTU. The stoichiometry of the bromate-DMABBA reaction was determined to be 2BrO(3)(-) + 3NHCH(3)(=NCH3)CSO2H + 3H(2)O -> 3SO(4)(2-) + 2Br(-) + 3CO(NHCH3)(2) + 6H(+), with quantitative formation of sulfate. In excess bromate conditions, the stoichiometry was 4BrO(3)(-) + 5NHCH(3)(=NCH3)CSO2H + 3H(2)O -> 5SO(4)(2-) + 2Br(2) + 5CO(NHCH3)(2) + 6H(+). The direct bromine-DMAIMSA reaction gave an expected stoichiometric ratio of 2:1 with no further oxidation of product dimethylurea (DMU) by aqueous bromine. The bromine-DMAIMSA reaction was so fast that it was close to diffusion-control led. Excess bromate conditions delivered a clock reaction behavior with the formation of bromine after an initial quiescent period. DMAIMSOA, on the other hand, was extremely inert to further oxidation in the acidic conditions used for this study. Rate of consumption of DMAIMSA showed a sigmoidal autocatalytic decay. The postulated mechanism involves an initial autocatalytic build-up of bromide that fuels the formation of the reactive oxidizing species HBrO2 and HCBr through standard oxybromine reactions. The long and weak C-S bond in DMAIMSA ensures that its oxidation goes directly to DMU and sulfate, bypassing inert DMAIMSOA.