Sodium Carbonate → 4-(1H-indazol-6-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester

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Reaction Conditions

Reaction Steps

To a mixture of 6-bromoindazole (2.0 g, 10.2 mmol), 4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester (3.5 g, 11.2 mmol) and Pd(PPh3)4 (1.2 g, 1.0 mmol) under N2 were added 1,4-dioxane (80 mL), followed by addition of K2CO3 (2 M in H2O, 20 mL, 40 mmol). The resulting mixture was heated at 110° C. for 16 h, then cooled to room temperature. The resulting mixture was then treated with saturated Na2CO3 aqueous solution. The resulting mixture was extracted with EtOAc (3×). The combined extracts were washed with brine and then dried over Na2SO4. The resulting mixture was filtered, concentrated under reduced pressure, and the residue purified by flash chromatography on silica-gel (gradient eluent heptane to 60% EtOAc in heptane) to yield 4-(1H-indazol-6-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester as brownish foam solid.

Provenance & Evidence