Cesium carbonate → 3-(4,5-dibromo-2-methyl-2H-pyrazol-3-yl)-8-(1-ethyl-propyl)-2,6-dimethyl-imidazo[1,2-b]pyridazine

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Reaction Conditions

Reaction Steps

8-(1-Ethyl-propyl)-2,6-dimethyl-imidazo[1,2-b]pyridazine (300 mg, 1.4 mmol), 3,4,5-tribromo-1-methyl-1H-pyrazole (700 mg, 2.1 mmol) and cesium carbonate (900 mg, 2.8 mmol) are stirred in DMF (5 ml) and degassed by bubbling a stream of nitrogen through the mixture. PdCl2(PPh3)2 (14 mg) is added and the mixture heated to 130° C. overnight. The mixture is added to water and extracted twice with EtOAc. The combined organic extracts are washed with brine, dried over Na2SO4, filtered and concentrated. The crude product is purified by chromatography using a hexane-ethyl acetate gradient (100% hexane to 20% ethyl acetate in hexane) to elute the title product (204 mg, 32% yield). ES-MS (m/z): calc'd for C17H21Br2N5: 455.2. found 455.9 (M+H)+. 1H NMR (400 mHz, CDCl3): δ 6.75 (s, 1H), 3.72 (s, 3H), 3.33 (m, 1H), 2.51 (s, 3H), 2.45 (s, 3H), 1.84 (m, 4H), 0.88 (t, 6H).

Provenance & Evidence