Sulfuric Acid → 5-Bromo-3-fluoropyridine-2-carbonitrile

To a mixture of H2SO4 (0.2 ml) and TBAF solution (131 ml, 131 mmol, 1M in THF) was added DMF (40 ml) dropwise at −40° C. Then a solution of 5-bromo-3-nitro-pyridine-2-carbonitrile (10 g, 43 mmol) in DMF (130 ml) was added at −40° C. and the reaction mixture was stirred for 1 h. The reaction was then quenched by addition of 2M HCl solution at −40° C. adjusting the pH to 3. The resulting mixture was extracted twice with EtOAc and the combined organic extracts were washed twice with water, with brine, dried with Na2SO4 and evaporated in vacuo. The remaining residue was purified by chromatography (silica gel; hexane/EtOAc 90:10-80:20) to obtain the title compound as yellow solid (5.2 g, 59%).

1. customThe reaction was then quenched by addition of 2M HCl solution at −40° C.
2. extractionThe resulting mixture was extracted twice with EtOAc
3. washthe combined organic extracts were washed twice with water, with brine
4. dry with materialdried with Na2SO4
5. customevaporated in vacuo
6. customThe remaining residue was purified by chromatography (silica gel; hexane/EtOAc 90:10-80:20)

ORD record

ord-b0de569a8bfe4b64bfbad894263ca59e

Source dataset

uspto-grants-2014_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08912221B2