Cesium carbonate → 6-chloro-4-(5-(ethylsulfonyl)pyridin-2-ylamino)-2-methylpyridazin-3(2H)-one

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Reaction Conditions

Reaction Steps

In a 250 mL round-bottomed flask, 5-(ethylsulfonyl)pyridin-2-amine (183 mg, 983 mmol), 4-bromo-6-chloro-2-methylpyridazin-3(2H)-one (263 mg, 1.18 mmol), xantphos (85.3 mg, 147 μmol) and Cs2CO3 (960 mg, 2.95 mmol) were combined with dioxane (10 mL) to give a light brown suspension. The flask was evacuated and filled with argon. Pd2(dba)3 (45.0 mg, 49.1 mmol) was added and the reaction mixture was stirred at 100° C. for 20 h under argon. Cooled to 25° C. and diluted with DCM. The reaction mixture was filtered through celite and the filter cake was washed with DCM until clear. The filtrate was concentrated and purified by flash chromatography (silica gel, 40 g, 0% to 2% MeOH in DCM) to afford 0.323 g (25%) of the title compound as a tan powder. (M+H)+=329/331 m/e. 1H NMR (300 MHz, DMSO-d6) δ: 10.18 (s, 1H), 8.78 (d, J=2.3 Hz, 1H), 8.12 (dd, J=8.9, 2.5 Hz, 1H), 7.74 (d, J=9.1 Hz, 1H), 3.69 (s, 3H), 3.32 (q, J=7.4 Hz, 2H), 1.11 (t, J=7.4 Hz, 3H).

Provenance & Evidence