Methyl formate → 3,5-Dibromo-4-pyridinecarboxaldehyde

Temperature

0 °C

A solution of diisopropylamine (6.6 mL, 46.43 mmol) in THF (40 mL) at 0° C. was treated with n-butyllithium in hexanes (2.50 M solution, 18.6 miL, 46.43 mmol) over 15 minutes, stirred at 0° C. for 30 minutes, diluted with THF (200 mL), cooled to −78° C., treated with 3,5-dibromopyridine (10 g, 42.21 mmol) in THF (110 mL) over 95 minutes, stirred at −78° C. for 30 minutes, treated dropwise with methylformate (5.2 mL, 84.42 mmol), stirred at −78° C. for 2 hours, transferred to ice-cold saturated NaHCO3 solution, stirred for 15 minutes, and extracted with diethyl ether. The extract was washed with brine, dried (MgSO4), filtered, and concentrated. The residue was purified by flash chromatography on silica gel with 10% acetone/hexane to provide the title compound. MS (DCI/NH3) m/z 266 (M+H)+; 1H NMR (300 MHz, DMSO-d6) δ 8.91 (s, 2H), 10.09 (s, 1H).

1. temperaturecooled to −78° C.
2. stirringstirred at −78° C. for 30 minutes
3. stirringstirred at −78° C. for 2 hours
4. stirringstirred for 15 minutes
5. extractionextracted with diethyl ether
6. washThe extract was washed with brine
7. dry with materialdried (MgSO4)
8. filtrationfiltered
9. concentrationconcentrated
10. customThe residue was purified by flash chromatography on silica gel with 10% acetone/hexane

ORD record

ord-e9438fdb7483423db1521c07bb3c5292

Source dataset

uspto-grants-2001_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06232320B1