Thermal decomposition of ibuproxam

The thermal behavior of ibuproxam was studied at several temperatures, and the degradation products were separated by column chromatography and ethereal extractions. The resulting products were ibuprofen [2-(4-isobutylphenyl)propionic acid], 1-(4-isobutylphenyl)-ethylamine, 4-isobutylacetophenone, and 4-isobutylacetophenone oxime. The compounds were identified by IR, UV, and NMR spectroscopy and elemental analyses. 4-Isobutylacetophenone was treated with hydrox-ylamine to give 4-isobutylacetophenone oxime.