Potassium Carbonate → Ethyl 2-(1-(tert-butoxycarbonyl)indolin-6-yl)thiazole-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of tert-butyl 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)indoline-1-carboxylate (28B) (69 mg, 0.2 mmol), ethyl 2-bromothiazole-4-carboxylate (43 mg, 0.2 mmol), K2CO3 (69 mg, 0.5 mmol), tetrabutylammonium bromide (6.0 mg, 0.02 mmol) and dichlorobis(triphenylphosphine)palladium(II) (6.0 mg, 0.003 mmol) in 1,4-dioxane (6 mL) and water (1 mL) was heated to 90° C. for 24 hours. After cooling the mixture was extracted into DCM, washed with H2O, dried over MgSO4, filtered, and concentrated under reduced pressure. The crude material was purified by column chromatography on silica gel eluting with a gradient of PE/EtOAc (9:1), to provide 46 mg (61%) of the desired product ethyl 2-O-(tert-butoxycarbonyl)indolin-6-yl)thiazole-4-carboxylate (28C): 1H NMR (300 MHz, CDCl3) δ 8.13 (1H, s), 7.18 (1H, dd), 6.95 (1H, dd), 6.43 (1H, dd), 4.44 (2H, m), 3.99 (2H, m), 3.11 (1H, t), 2.97 (1H, t), 1.54 (9H, s), 1.45 (3H, t). LC/MS (APCI): m/z 375.0 (M+H).

Provenance & Evidence