George H. Millet

N-oxides and related compounds. Part 60. Novel thermal and photochemical rearrangements of N-substituted 2-pyridones

Examples of four novel rearrangements of derivatives of 1-hydroxy-4,6-diphenyl-2-pyridone are reported: all involve N–O fission and formation of 3-substituted or both 3- and 5-substituted-4,6-diphenyl-2-pyridones. (a) 1-OCH2CH2R (R = vinyl or phenyl) compounds give 3-CH2R (R = vinyl or phenyl) derivatives with elimination of CH2O. (b) The 1-octyloxy-compound gives the 3-octyloxy-derivative by simple transposition. (c) 1-Acyloxy-compounds form the corresponding 3- and 5-acyloxy-2-pyridones. (d) 1-Imidoyloxy-compounds yield the rearranged 3-and 5-amido-2-pyridones. The mechanisms probably all involve homolytic N–O fission.

Heterocycles in organic synthesis. Part 25. Reagents for the conversion of halides into aldehydes and ketones

The sodium salts of 1-hydroxy-4,6-diphenyl-2-pyridone, 3-hydroxy-2-phenyl-4(3H)-quinazolinone, and 2-benzenesulphonamidopyridine 1-oxide react with alkyl and benzyl halides to give crystalline N-alkoxy- and N-benzyloxy-derivatives. The latter undergo thermolysis and photolysis to aromatic aldehydes and ketones in high yields. N-Alkoxy-analogues similarly yield aliphatic carbonyl compounds but these are contaminated by significant amounts of the corresponding alcohol.

Heterocycles in organic synthesis. Part 26. Conversion of primary amines into aldehydes

Triphenyipyridinium tetrafluoroborate derivatives, derived from alkyl, allyl, benzyl, and picolyl primary amines and triphenylpyrytium salts, react with sodium 1-oxido-4,6-diphenyl-2-pyridone to yield aldehydes, formed by thermolysis of intermediate 1-alkoxypyridones

Novel thermal and photochemical rearrangements of N-substituted 2-pyridones

Examples of four novel rearrangements of 1-substituted 4,6-diphenyl-2-pyridones are reported: (a) 1-phenethoxy and 1-but-3-enoxy give 3-benzyl and 3-prop-2-enyl derivatives, respectively, with elimination of CH2O; (b) 1-octyloxy gives 3-octyloxy; (c) 1-α-(p-tolylimino)benzyloxy gives 3- and 5-N-benzoyl-p-toluidino; (d) 1-p-toluoyloxy gives 3- and 5-p-toluoyloxy-derivatives.