Imidazole → 5-Bromo-2-({[t-butyl(dimethyl)silyl]oxy}methyl)pyridine

To a solution of 5-bromo-2-formylpyridine (4.6 g, 25 mmol) in methanol (30 ml) was added sodium borohydride (0.93 g, 25 mmol) at 0° C. with stirring, and the resulting mixture was stirred for 1 hour. After evaporating the solvent in vacuo, the residue obtained was diluted with ether, poured into water (20 ml) and extracted with ethyl acetate. The extract was washed with a saturated aqueous solution of sodium chloride and dried over magnesium sulfate. After filtration, the filtrate was evaporated in vacuo. Subsequently, to a solution of the residue obtained and imidazole (3.4 g, 49 mmol) in N,N-dimethylformamide (30 ml) was added t-butyldimethylsilyl chloride (4.1 g, 27 mmol) with stirring, and the resulting mixture was stirred at room temperature for 1 hour. After stirring, the reaction mixture was poured into water (50 ml) and extracted with ether. The extract was washed with a saturated aqueous solution of sodium chloride and dried over magnesium sulfate. After filtration, the filtrate was evaporated in vacuo, and the crude product of the title compound thus obtained was purified by chromatography on a silica gel column using a mixed solvent of ethyl acetate and hexane (1:49 to 1:9) as the eluent to afford the title compound (6.8 g) in a yield of 90% as a white crystalline solid.

1. stirringthe resulting mixture was stirred for 1 hour
2. customAfter evaporating the solvent in vacuo
3. customthe residue obtained
4. extractionextracted with ethyl acetate
5. washThe extract was washed with a saturated aqueous solution of sodium chloride
6. dry with materialdried over magnesium sulfate
7. filtrationAfter filtration
8. customthe filtrate was evaporated in vacuo
9. customSubsequently, to a solution of the residue obtained
10. stirringwith stirring
11. stirringthe resulting mixture was stirred at room temperature for 1 hour
12. stirringAfter stirring
13. extractionextracted with ether
14. washThe extract was washed with a saturated aqueous solution of sodium chloride
15. dry with materialdried over magnesium sulfate
16. filtrationAfter filtration
17. customthe filtrate was evaporated in vacuo

ORD record

ord-aa422882b19d4d09b58be5feefcca6e4

Source dataset

uspto-grants-2010_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07687491B2