Tetrabutylammonium Fluoride → 5-bromo-1H-pyrrolo[2,3-b]pyridine

To a solution of N-(5-bromo-3-trimethylsilanylethynyl-pyridin-2-yl)-acetamide (4.75 g, 15.26 mmol) in THF (90 ml) was added dropwise a 1 m solution of tetra-n-butyl ammonium fluoride in THF (30.5 ml, 30.5 mmol). After stirring at reflux for 15 hours, the reaction mixture was concentrated in vacuo and water was added. The aqueous layer was extracted three times with dichloromethane with, and the combined extracts were directly adsorbed on silica gel. Purification by flash chromotography on silica gel with a gradient of ethyl acetate/hexanes afforded 2.29 g of a beige solid. Recrystallization from ethyl acetate/hexanes provided the title compound as light beige flakes (1.33 g). Further purification of the filtrate on silica gel with a gradient of ethyl acetate/hexanes afforded more of the title compound as a crystalline powder (675 mg) for a combined yield of 2.01 g; 67%. 1H NMR (DMSO-d6): δ 11.89 (s, 1H), 8.24 (d, J=2.0 Hz, 1H), 8.17 (d, J=2.5 Hz, 1H), 7.53 (f, J=3.0 Hz, 1H), 6.42 (dd, J=1.0, 3.0 Hz, 1H); HPLC/MS m/z: 197 [MH]+.

1. temperatureat reflux for 15 hours
2. concentrationthe reaction mixture was concentrated in vacuo and water
3. additionwas added
4. extractionThe aqueous layer was extracted three times with dichloromethane with, and the combined extracts
5. customPurification by flash chromotography on silica gel with a gradient of ethyl acetate/hexanes

ORD record

ord-7770d62d9a1647629ee30fb4b3b59aab

Source dataset

uspto-grants-2011_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07906648B2