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

At 0° C., 859 ml (859 mmol) of a 1 M solution of borane-tetrahydrofuran complex in tetrahydrofuran are added dropwise to 110 g (573 mmol) of 5,6-dichloronicotinic 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 aqueous sodium chloride solution and dried over sodium sulphate. Concentration under reduced pressure and purification of the residue by column chromatography on silica gel (silica gel 60-Merck, particle size: 0.04 to 0.063 mm) using the mobile phase mixture ethyl acetate:cyclohexane (1:2) gives 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 aqueous sodium chloride solution
6. dry with materialdried over sodium sulphate
7. concentrationConcentration
8. customunder reduced pressure and purification of the residue by column chromatography on silica gel (silica gel 60-Merck, particle size: 0.04 to 0.063 mm)

ORD record

ord-da89de5956844d36bbd36428a77212e3

Source dataset

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08106212B2