Cesium carbonate → 6-Chloro-4-(6-[1,2,3]triazol-1-yl-pyridin-2-ylamino)-pyridazine-3-carboxylic acid ethyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

4,6-Dichloro-pyridazine-3-carboxylic acid ethyl ester (200 mg, 0.905 mmol) and 6-[1,2,3]triazol-1-yl-pyridin-2-ylamine (147 mg, 0.914 mmol) were dissolved in 1,4-dioxane (6 mL) and the solution was purged with argon. Tris(dibenzylideneacetone)dipalladium (83 mg, 0.09 mmol), Xantphos (105 mg, 0.18 mmol), and cesium carbonate (884 mg, 2.7 mmol) were added and the reaction mixture was heated to 100° C. for 1 h. The reaction mixture was cooled, diluted with saturated aqueous sodium bicarbonate solution, then extracted with ethyl acetate. The combined organic extracts were washed with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered and concentrated in vacuo. Purification by chromatography (silica, 25 to 100% ethyl acetate in hexanes) gave 6-chloro-4-(6-[1,2,3]triazol-1-yl-pyridin-2-ylamino)-pyridazine-3-carboxylic acid ethyl ester (48 mg, 15%) as a light yellow solid. 1H NMR (300 MHz, CHLOROFORM-d) δ ppm 9.34-9.43 (m, 1H) 8.54-8.57 (m, 1H) 8.43 (d, J=1.1 Hz, 1H) 7.87-7.97 (m, 3H) 7.60 (dd, J=7.4, 1.3 Hz, 1H) 4.55 (q, J=7.2 Hz, 2H) 1.50 (t, J=7.2 Hz, 3H); MS (EI/CI) m/z: 346 [M+H].

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