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 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 ethylacetate (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 ethylacetate (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-d8d9216177fe40bc9c45c6b6b3079fa4

Source dataset

uspto-grants-2011_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07943619B2