AQUEOUS HIGH-TEMPERATURE CHEMISTRY OF CARBOCYCLE AND HETEROCYCLE .29.REACTIONS OF ARYL HYDROCARBONS, ARYL N-OXIDES, AND ARYL CARBONYL-COMPOUNDS IN SUPERCRITICAL WATER AT 460-DEGREES-C

A series of aryl hydrocarbons, aryl N-oxides, and aryl carbonyl compou nds were subjected to thermolysis at 460 degrees C in water alone, in 15% aqueous formic acid, in 15% aqueous sodium formate, and, for compa rison of purely thermal reactions, in cyclohexane. The runs were carri ed out initially for 7 min and, in most cases, also for 1 h. The aryl carbonyl substrates underwent mainly carbonyl reduction mainly under r educing conditions, with ring opening only observed in significant amo unts for 1,4-naphthoquinone and 3,4-benzocoumarin. The arenes produced mainly reduction products with only low yields of ring-opened product s observed. Aryl oximes underwent significant denitrogenation and subs equent reduction with only very little cleavage to simpler aromatic sy stems. The N-oxides underwent deoxygenation, and in the case of isoqui noline, ring opening of the heterocycle was prevalent. 2-Aminobiphenyl was denitrogenated and cleaved to simpler systems in cyclohexane, but in the aqueous systems it underwent mainly cyclization to yield carba zole with only low yields of denitrogenated products. 2-Phenylphenol w as unreactive under aqueous conditions with only low yields of deoxyge nated products observed.