1990 年 110 巻 6 号 p. 449-452
The Friedel-Crafts reactions of N-alkyl-2(1H)-pyridone and its derivatives with acid anhydride were carried out. In the cases of N-benzyl-2(1H)-pyridone(1a) and N-benzyl-2(1H)-pyridone(1b), reaction with benzoic anhydride (2a) gave 5-benzoyl compounds (3a, b) and 3, 5-dibenzoyl compounds (4a, b), respectively, in good yields. Reactions of 1a, b with acetic anhydride (2b) gave only 5-acetyl compounds (5a, b). Reactions of dimethyl-2(1H)-pyridone(6a-d) bearing the methyl group on the pyridone ring with 2a were carried out. Only 6a gave 5-benzoyl-1, 3-dimethyl compound (7) and 6b-d gave no benzoyl compound. Reactions of 6a, b and 6d with 2b gave 5-acetyl compounds (8a, b, d), but reaction of 6c with 2b gave no acetyl compound. The result that reactions of 6b and 6d with 2a gave no benzoyl compound may be attributed to the steric hindrance between one methyl group on the pyridone ring and the reagent. Reactions of thiolactam compounds (thiopyridone, thioquinolone) with 2a gave 5-benzoylpyridone (3c) and 6-benzoylquinolone (11) in poor yields, respectively.