Studies on 3,5-diaminopyrazole derivatives

Synthesis and tautomerism of aryl- and hetaryl-azo derivatives of bi- and tri-heterocycles

“…Similar reaction of N-phenyl benzenecarbohydrazonoyl chloride 1I with 3,5-diamino-4-phenylazopyrazole 51 was reported to yield 53 probably via elimination of ammonia from the intermediate amidrazone 52 (Scheme 17) [36,37]. However, reactions of the same diaminopyrazole 51 with 2-oxohydrazonoyl chlorides 1A and 1C were reported to give the respective amidrazones 54 (Scheme 17) [21,37].…”

“…However, reactions of the same diaminopyrazole 51 with 2-oxohydrazonoyl chlorides 1A and 1C were reported to give the respective amidrazones 54 (Scheme 17) [21,37]. No attempts to cyclize the latter, however, were reported.…”

Reactions of heterocyclic compounds with nitrilimines and their precursors

“…) react with 5-amino-4-bromo-3-phenylpyrazole (82c) and yield the pyrazolo[5,l-c]-1,2,4-triazoles 102 via elimination of ammonia from the intermediate 1,3-adducts 101.106107 l,3-Diphenyl-5-aminopyrazole (82f) reacts with nitrilimines of type le, lg, and lh and yields the 1,3addition products 108a, 108b, and 108c, respective-;CH3CO ; b, R =C2H5OCO ; c , R = CsH5NHCO 3,5-Diamino-4-phenylazopyrazole (82g) reacts with C-acetyl-and C-(phenylcarbamoyl)nitrilimines le and lh and yields the corresponding 1,3-addition products 109a and 109b, respectively.106'107'109 Contrary to this, -4-cyano-3-phenylpyrazole (82d) yielded the 1,3-addition products 103 and 104 when reacted with C-acetyl-and C-phenyl-iV-arylnitrilimines (leand la), respectively.107 Reactions of both la and le with that the reaction of diphenylnitrilimine (la) with 82g yielded the pyrazolo[5,l-c]-l,2,4-triazole111 probably via elimination of ammonia from the 1-3-methyl-4-phenylpyrazole (82e) were reported to give the corresponding pyrazolo[5,l-c]-l,2Diamino-3-(ethoxycarbonyl)pyrazole(…”