Hydrochloric Acid → 6-Bromo-3-pyridinecarboxaldehyde

Temperature

-80 °C

To a suspension of 2,5-dibromopyridine (2.00 g, 8.44 mmol) in dry diethyl ether (25 mL) was added n-BuLi (3.55 mL, 8.87 mmol, 2.5 M solution in hexane) at −80° C. under a nitrogen atmosphere. After stirring for 1 h at −80° C. dry DMF (0.68 mg, 9.28 mmol) was added. After stirring for an additional hour at −80° C. the reaction mixture was allowed to warm to 0° C. and HCl (18.0 mL, 1 M) was added. After stirring for 15 minutes the phases were separated and aqueous layer was extracted twice with diethyl ether. The combined organic layers were washed with water (50 mL), brine (50 mL) and dried over MgSO4. The organic phase was concentrated under reduced pressure and the crude product was purified by flash chromatography on silica-gel using a mixture of hexane/ethyl acetate (8:1) as eluent. White solid. Yield: 1.03 g, 66%. 1H NMR (CDCl3, 500 MHz): δH (ppm)=7.67-7.71 ppm (m, 1H), 8.02 (dd, J=8.2, 2.5 Hz, 1H), 8.84 (dd, J=2.5, 0.6 Hz, 1H), 10.10 (s, 1H); 13C NMR (CDCl3, 125 MHz): δC (ppm)=129.0, 130.6, 137.5, 148.3, 152.5, 189.4; MS (ESI): m/z=187.19 [M+H]+.

1. additionwas added
2. temperatureto warm to 0° C.
3. stirringAfter stirring for 15 minutes the phases
4. customwere separated
5. extractionaqueous layer was extracted twice with diethyl ether
6. washThe combined organic layers were washed with water (50 mL), brine (50 mL)
7. dry with materialdried over MgSO4
8. concentrationThe organic phase was concentrated under reduced pressure
9. customthe crude product was purified by flash chromatography on silica-gel
10. additiona mixture of hexane/ethyl acetate (8:1) as eluent

ORD record

ord-68a6ef275bc14c528c709579930b55df

Source dataset

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09394290B2