Benzyl chloroformate → benzyl 4-chloro-1H-pyrrolo[2,3-b]pyridine-5-carboxylate

To a reaction solution of 4-Chloro-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridine (2.26 g) in tetrahydrofuran (16 ml) was added sec-butyllithium (14.6 ml) dropwise in nitrogen atmosphere at −78° C. After the mixture was stirred at the same temperature for 30 minutes, a solution of benzyl chloroformate (2.1 ml) in tetrahydrofuran (16 ml) was added dropwise to the reaction mixture at −78° C. Furthermore, the reaction solution was stirred at −78° C. for 15 minutes, neutralized with saturated aqueous ammonium chloride (12 ml), and extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over magnesium sulfate, and evaporated under reduced pressure. The residue was dissolved in tetrahydrofuran (17 ml), 1M tetrabutylammonium fluoride/tetrahydrofuran solution (16.9 ml) was added, and the mixture was stirred at ambient temperature for 3 hours. To the reaction solution were added ethyl acetate and water, the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over magnesium sulfate, and evaporated under reduced pressure. The residue was purified by silica gel column chromatography (n-hexane:ethyl acetate) to obtain benzyl 4-chloro-1H-pyrrolo[2,3-b]pyridine-5-carboxylate (690 mg).

1. stirringFurthermore, the reaction solution was stirred at −78° C. for 15 minutes
2. extractionextracted with ethyl acetate
3. washThe organic layer was washed with saturated brine
4. dry with materialdried over magnesium sulfate
5. customevaporated under reduced pressure
6. dissolutionThe residue was dissolved in tetrahydrofuran (17 ml)
7. addition1M tetrabutylammonium fluoride/tetrahydrofuran solution (16.9 ml) was added
8. stirringthe mixture was stirred at ambient temperature for 3 hours
9. additionTo the reaction solution were added ethyl acetate and water
10. extractionthe mixture was extracted with ethyl acetate
11. washThe organic layer was washed with saturated brine
12. dry with materialdried over magnesium sulfate
13. customevaporated under reduced pressure
14. customThe residue was purified by silica gel column chromatography (n-hexane:ethyl acetate)

ORD record

ord-046c73f268fb443ba454f99cd529a231

Source dataset

uspto-grants-2011_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07879844B2