Potassium Carbonate → (5,6-Dichloropyridin-3-yl)methanol

At 0° C., 859 ml (859 mmol) of a 1 M solution of boran/tetrahydrofuran complex in tetrahydrofuran are added dropwise to 110 g (573 mmol) of 5,6-dichloro-nicotinic acid in 250 ml of tetrahydrofuran. The mixture is warmed to room temperature and stirred at this temperature for 3 hours. After cooling to 0° C., the reaction mixture is made alkaline using saturated aqueous potassium carbonate solution, most of the tetrahydrofuran is removed using a rotary evaporator and the residue is extracted repeatedly with ethyl acetate. The combined organic phases are washed with water and saturated in aqueous sodium chloride solution and dried over sodium sulphate. The organic phase is concentrated under reduced pressure and the residue is purified by column chromatography on silica gel (silica gel 60-Merck, particle size: 0.04 to 0.063 mm) using the molar phase mixture ethyl acetate:cyclohexane (1:2), giving 62 g (61% of theory) of (5,6-dichloropyridin-3-yl)methanol.

1. temperatureAfter cooling to 0° C.
2. custommost of the tetrahydrofuran is removed
3. customa rotary evaporator
4. extractionthe residue is extracted repeatedly with ethyl acetate
5. washThe combined organic phases are washed with water and saturated in aqueous sodium chloride solution
6. dry with materialdried over sodium sulphate
7. concentrationThe organic phase is concentrated under reduced pressure
8. customthe residue is purified by column chromatography on silica gel (silica gel 60-Merck, particle size: 0.04 to 0.063 mm)

ORD record

ord-4280ddb9d4bf44e6951da7d979d4a94e

Source dataset

uspto-grants-2012_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08138350B2