Metabolism of the dyestuff intermediate 2,4-diaminoanisole in the rat.

1. 2,4-Diamino[ring-U-14C]anisole.2HCl administered intraperitoneally to rats is excreted chiefly via the urine (79 and 85% of the dose in 24 and 48 h, respectively). The isotope in the faeces was 2.1 and 8.9% of the dose at 24 and 48 h. 2. The major metabolic pathway was acetylation of the amine groups(s), resulting in 4-acetylamino-2-aminoanisole and 2,4-diacetylaminoanisole. 3. Oxidate pathways yielded 2,4-diacetylaminophenol (O-demethylation), 5-hydroxy-2,4-diacetylaminoanisole (ring hydroxylation), and 2-methoxy-5-(glycol-amido)acetanilide or its isomer (omega-oxidation). 4. These major metabolites were excreted in the urine both as free and glucuronic acid conjugates.