3,5-Difluorobenzaldehyde 2-(6-chloro-5-cyclobutyl-3-pyridazinyl)hydrazone → 6-Chloro-7-cyclobutyl-3-(3,5-difluorophenyl)-1,2,4-triazolo[4,3-b]pyridazine

Participants

Reaction Conditions

Reaction Steps

Ferric chloride (3.423 g, 12.66 mmol) in ethanol (15 ml) was added dropwise to a solution of N-(6-chloro-5-cyclobutylpyridazin-3-yl)-N′-(3,5-difluorobenzylidene)hydrazine (0.816 g, 2.53 mmol) in ethanol (35 ml) and heated at 70° C. After 3 hours the reaction mixture was partitioned between dichloromethane (250 ml) and brine (250 ml). The organic phase was dried (MgSO4), filtered and evaporated. The residue was purified by chromatography on silica gel, eluting with ethyl acetate-hexane mixtures to afford the title pyridazine (0.51 g, 63%). 1H NMR (250 MHz, CDCl3) 1.84-2.08 (1H, m), 2.08-2.36 (3H, m), 2.42-2.68 (2H, m), 3.65-3.87 (1H, m), 6.88-7.06 (1H, m), 8.01 (1H, s), 8.04-8.21 (2H, m). MS (ES+) 321 [MH]+, 323 [MH]+.

Provenance & Evidence