Cesium carbonate → Ethyl 2-(1-acetyl-1,2,3,4-tetrahydroquinolin-7-yl)-5-chlorothiazole-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

To 1-(7-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4-dihydroquinolin-1(2H)-yl)ethanone (1G) (1.24 g, 4.12 mmol), ethyl 2-bromo-5-chlorothiazole-4-carboxylate (1I) (1.12 g, 4.12 mmol), lithium chloride (0.52 g, 12.4 mmol), tetrakis(triphenylphosphine)palladium (0.476 g, 0.412 mmol), and cesium carbonate (4.03 g, 12.4 mmol) was added 1,4-dioxane (30 mL) and water (10 mL). Nitrogen was bubbled through the reaction mixture for 5 minutes. The reaction mixture was heated to 100° C. and stirred overnight. The reaction mixture was cooled to rt, diluted with EtOAc, filtered through Celite, and concentrated under reduced pressure. To the crude residue was added EtOAc and water. The layers were separated and the aqueous layer was extracted with EtOAc and the combined organic extracts were washed sequentially with water, brine, dried over MgSO4, filtered, and concentrated under reduced pressure. The crude residue was purified by column chromatography on silica gel eluting with a gradient of 0 to 80% EtOAc in hexanes to provide 0.505 g (34%) of the desired product ethyl 2-(1-acetyl-1,2,3,4-tetrahydroquinolin-7-yl)-5-chlorothiazole-4-carboxylate (1J): LC/MS (APCI): m/z 365.3 (M+H).

Provenance & Evidence