Synthesis of 5-(<img src='/image/spc_char/delta.gif' border=0>²-5'-aryl-3'-isoxazolyl)-3,6-dimethylisoxazolo[4,5-<i>b</i>]pyridines

1927-1930Isoxazolopyridine-N-oxides 2 are deoxygenated to pyridines 3 by treatment with PCl3. 5-Acetyl-3,6-dimethylisoxazolo[4,5-b]­pyri­dine 3 is condensed with aromatic aldehydes to give , -unsaturated carbonyl moiety at position-5, which then cyclizes to isoxazole ring by reaction with hydroxylamine hydrochloride in sodium acetate-acetic acid to result in title compounds 7. All the new compounds 3-7 have been characterized by elemental analyses and spectral (IR, 1H NMR and mass) data.