Potassium Phosphate, Tribasic → Methyl 4-(imidazo[1,2-b]pyridazin-3-yl)thiophene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

3-Bromoimidazo[1,2-b]pyridazine (700 mg, 3.53 mmol), methyl 5-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene-2-carboxylate (1.04 g, 3.89 mmol), Pd2(dba)3 (324 mg, 0.353 mmol), tricyclohexylphosphine (248 mg, 0.884 mmol), aqueous tribasic potassium phosphate (2.54 mL, 12.0 mmol, 1.27 M), and 1,4-dioxane (17.7 mL) were placed in a sealed tube and purged with nitrogen for 5 minutes. The solution was heated to 100° C. for 1.5 h, after which the reaction was cooled to room temperature. Saturated aqueous sodium bicarbonate was added to the mixture. The aqueous layer was then extracted with ethyl acetate (×3). The combined organic layers were then dried with magnesium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by flash chromatography affording the title compound as a yellow solid. 1H NMR (500 MHz, CD3SOCD3) δ 8.70 (d, 1H); 8.68 (s, 1H); 8.54 (s, 1H); 8.42 (s, 1H); 8.22 (d, 1H); 7.31 (dd, 1H); 3.86 (s, 3H). LRMS (APCI) calc'd for (C12H9N3O2S) [M+H]+, 260.0. found 260.0.

Provenance & Evidence