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

Temperature

110 °C

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.

1. temperaturecooled to room temperature
2. extractionThe resulting mixture was extracted with EtOAc (3×)
3. washThe combined extracts were washed with brine
4. dry with materialdried over Na2SO4
5. filtrationThe resulting mixture was filtered
6. concentrationconcentrated under reduced pressure
7. customthe residue purified by flash chromatography on silica-gel (gradient eluent heptane to 60% EtOAc in heptane)

ORD record

ord-4a50c4d2f95c495ca72eca4eeaccd606

Source dataset

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08822447B2