Cesium carbonate → 5-Cyclopropyl-6-(2,2,2-trifluoro-ethoxy)-pyridine-2-carboxylic acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

In a 150 ml round-bottom-flask, Pd(OAc)2 (15.7 mg, 70.0 μmol), butyl-1-adamantylphosphin (37.6 mg, 105 μmol), potassium cyclopropyltrifluoroborate (523 mg, 3.53 mmol), cesium carbonate (3.42 g, 10.5 mmol) and 5-bromo-6-(2,2,2-trifluoroethoxy)picolinic acid (Example 282a) (1.05 g, 3.5 mmol) were combined. The flask was evacuated in vacuo and flushed with argon three times, followed by addition of a mixture toluene (25 ml)/H2O (3 ml) through a septum cap. The reaction mixture was heated to 120° C., stirred for 20 h and then cooled to ambient temperature. Evaporation of volatiles in vacuo and the residue was redissolved in ethyl acetate and extracted with 1M HCl (12.5 ml). The aqueous phase was back-extracted with ethyl acetate. The combined organic layers were dried over Na2SO4 and concentrated in vacuo The crude material was purified by flash chromatography (silica gel, 50 g, 0% to 5% MeOH in DCM) to give the title compound (530 mg, 58%). MS (EI): m/e=262.2[M+H]+.

Herkunft & Nachweise