Abstract
Various 1-or 3- (substituted 3-amino) indazoles with anti-inflammatory effects were synthesized by means of three methods, as follows. 1) Reactions of 3-aminoindazole (1) with acrylamides (2a and 2b) gave amide derivatives (3a and 3b) having a carbamoylethylamino group at the 3-position of 3a and 3b. The amide derivatives (3a and 3b) were converted to thioamide derivatives (4a and 4b) by treatment with P2S5. Electrode reduction of 4a and 4b gave 3- (substituted 3-amino) indazoles (5a and 5b). 2) The reaction of 1 with aminoalkyl. halides (6c-r) gave 3- (substituted 3-amino) indazoles (5c-r) and 1- (substituted 3-amino) indazoles (7c-r) in a ratio of 3 : 1. 3) The reaction of 1 with phthalic anhydride (8) gave 3-phthalimidoindazole (9). Compound 9 was allowed to react with aminoalkyl halides (6o-r) to give 1-substituted derivatives (10s-z) of 9, Reactions of 10a-z with hydrazine hydrate gave 1- (substituted 3-amino) indazole derivatives (5s-z).
