Hydrazine hydrate (1:1) → 6-Chloro-5-(morpholin-4-yl)pyridazin-3-ylhydrazine

Participants

Reaction Steps

A mixture of 4-(3,6-dichloropyridazin-4-yl)morpholine (5 g, 21.3 mmol) and hydrazine hydrate (7.0 ml, 141 mmol) in 1,4-dioxane (100 ml) was stirred and heated at reflux for 20 hours. Upon cooling the 1,4-dioxane was removed in vacuo. The residue was then partitioned between dichloromethane and saturated aqueous sodium hydrogen carbonate. The aqueous layer was further extracted with dichloromethane (×2). The combined organic extracts were dried (Na2SO4), filtered and evaporated. The residue was purified by chromatography on silica gel, eluting with dichloromethane/methanol/aqueous ammonia (91:8:1) to give 6-chloro-5-(morpholin-4-yl)pyridazin-3-ylhydrazine (3.6 g, 74%): 1H NMR (250 MHz, d6-DMSO) δ3.17-3.37 (4H, m), 3.72-3.77 (4H, m), 4.31 (2H, br s), 6.58 (1H, s), 7.97 (1H, br s); MS (ES+) m/e 230, 232 [MH+].

Provenance & Evidence