5,6-Dimethylpyridin-2(1H)-imine → Ethyl 6-chloro-4-(5,6-dimethylpyridin-2-ylamino)pyridazine-3-carboxylate

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Reaction Conditions

Reaction Steps

A pressure tube was charged with ethyl 4,6-dichloropyridazine-3-carboxylate (300 mg, 1.36 mmol), 5,6-dimethylpyridin-2-amine (249 mg, 2.04 mmol) in acetonitrile (8 mL) and the mixture was heated in an oil bath at 140° C. for 18 h. After cooling to room temperature, the mixture was concentrated in vacuo, adsorbed on silica gel and then purified by chromatography (silica, 50 μm, 80 g column from Analogix, 0% to 10% acetone in dichloromethane, 20 min) to afford ethyl 6-chloro-4-(5,6-dimethylpyridin-2-ylamino)pyridazine-3-carboxylate (150 mg, 36%) as a yellow solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 10.20 (s, 1H) 8.86 (s, 1H) 7.57 (d, J=8.08 Hz, 1H) 6.97 (d, J=8.08 Hz, 1H) 4.40 (q, J=7.24 Hz, 2H) 2.42 (s, 3H) 2.23 (s, 3H) 1.35 (t, J=7.20 Hz, 3H); LCMS (EI/CI) m/z: 307 [M+H].

Provenance & Evidence