Triethylamine → Ethyl 6-chloro-(1,2,4)triazolo(4,3-b)pyridazine-3-carboxylate

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Reaction Steps

A mixture of compound ethyl 2-bromo-2-(2-(6-chloropyridazin-3-yl)hydrazono)acetate (1.25 g, 4 mmol) in 10 mL of isopropanol with 0.5 mL of triethylamine was refluxed for 1 h. The solution was evaporated and the residue was washed thoroughly with water to give product ethyl 6-chloro-[1,2,4]triazolo[4,3-b]pyridazine-3-carboxylate as a yellow solid (0.8 g, 67%). LRMS (M+H+) m/z: calcd 227.03; found 227. 1H NMR (300 MHz, CDCl3): δ 8.25-8.22 (d, J=9.6 Hz, 1H), 7.34-7.31 (d, J=9.6 Hz, 1H), 4.64-4.56 (q, 2H), 1.53-1.49 (t, 3H).

Provenance & Evidence