Triethylamine → N'-(6-Chloro-5-(trimethylsilyl)pyridazin-3-yl)-2-fluorobenzohydrazide

Participants

Reaction Conditions

Reaction Steps

To a stirred mixture of 3-chloro-6-hydrazino-4-(trimethylsilyl)pyridazine (6.34 g, 29.3 mmol) and anhydrous triethylamine (4.9 ml, 35.2 mmol) in anhydrous diethyl ether (100 ml), cooled under nitrogen to −4° C., was added dropwise, over 13 min, 2-fluorobenzoyl chloride (3.5 ml, 29.4 mmol) keeping the temperature below 5° C. The thick mixture was then stirred for 30 min at 0-5° C., then quenched with anhydrous methanol (1 ml). The mixture was diluted with hexane (100 ml) and filtered. The collected solid was washed with diethyl ether (2×25 ml), then water (100 ml), then dissolved in dichloromethane (300 ml) and methanol (20 ml), washed with saturated aqueous NaCl (100 ml), dried (Na2SO4), and evaporated in vacuo to leave 9.72 g (98%) of the title compound as a pale brown solid; 1H NMR (360 MHz, CDCl3) δ 0.36 (9H, s), 7.07 (1H, s), 7.20 (1H, dd, J=11.7 and 8.2 Hz), 7.30 (1H, t, J=7.6 Hz), 7.55 (1H, m), 8.00 (1H, br s), 8.07 (1H, td, J=7.7 and 1.8 Hz), 9.19 (1H, br s); MS (ES+) m/e 339/341 [MH]+, 217/219 [M-COC6H4F+2H]+.

Provenance & Evidence