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

Temperature

-78 °C

To a solution of 4-chloro-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]-pyridine (15 g) in tetrahydrofuran (150 mL) was added 1M sec-butyllithium in tetrahydrofuran (97 mL) dropwise at −78° C. The mixture was stirred at −78° C. for 1 hour. To the mixture was added ethyl chloroformate (9.29 mL) and the mixture was stirred at −78° C. for 0.5 hour. The reaction mixture was quenched with saturated ammonium chloride aqueous solution and extracted with EtOAc. The extract was wash with water and brine, dried over MgSO4 and concentrated under reduced pressure. The residue was dissolved in tetrahydrofuran (120 mL) and to the solution was added 1M tetra-n-butylammonium fluoride in tetrahydrofuran (56 mL). The mixture was stirred at ambient temperature for 1 hour and then extracted with EtOAc. The extract was washed with water, dried over MgSO4 and concentrated under reduced pressure. The residue was with diisopropyl ether to give ethyl 4-chloro-1H-pyrrolo[2,3-b]pyridine-5-carboxylate.

1. stirringthe mixture was stirred at −78° C. for 0.5 hour
2. customThe reaction mixture was quenched with saturated ammonium chloride aqueous solution
3. extractionextracted with EtOAc
4. washThe extract was wash with water and brine
5. dry with materialdried over MgSO4
6. concentrationconcentrated under reduced pressure
7. dissolutionThe residue was dissolved in tetrahydrofuran (120 mL) and to the solution
8. additionwas added 1M tetra-n-butylammonium fluoride in tetrahydrofuran (56 mL)
9. stirringThe mixture was stirred at ambient temperature for 1 hour
10. extractionextracted with EtOAc
11. washThe extract was washed with water
12. dry with materialdried over MgSO4
13. concentrationconcentrated under reduced pressure

ORD record

ord-4ff5c50a66ed485b874cea449e413870

Source dataset

uspto-grants-2012_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08163767B2