Dimethylformamide → 5-Chloropyridine-2-carboxaldehyde

Temperature

0 °C

To a solution of 2-bromo-5-chloropyridine (14.8 g, 77 mmol) in THF (38.5 mL) was added dropwise a solution of i-PrMgCl.LiCl (14% in THF, 81 mL, 85 mmol) at 0-5° C. and the resulting mixture stirred at 0° C. for 1 h. Then DMF (7.7 mL, 100 mmol) was added dropwise at −5° C. and the temperature maintained at 0° C. for 2 h. The reaction mixture was then poured into ice cold saturated brine (500 mL) and then extracted with ethyl acetate (2×300 mL). The combined organic layers were washed with saturated sodiumhydrogencarbonate solution, brine, dried over sodium sulfate, filtered and evaporated. Purification by chromatography (SiO2, heptane:ethyl acetate=1:0 to 9:1) afforded the title compound (6.24 g, 57%) which was obtained as a brown solid. MS: m/e=141.0 [M]+.

1. extractionextracted with ethyl acetate (2×300 mL)
2. washThe combined organic layers were washed with saturated sodiumhydrogencarbonate solution, brine
3. dry with materialdried over sodium sulfate
4. filtrationfiltered
5. customevaporated
6. customPurification by chromatography (SiO2, heptane:ethyl acetate=1:0 to 9:1)

ORD record

ord-de87a9e4f9114dd0a6d8c046b5b0f83f

Source dataset

uspto-grants-2013_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08518974B2