Iodine → 4-Chloro-5-iodo-1H-pyrrolo[2,3-b]pyridine

Temperature

-78 °C

s-BuLi (59.3 mL, 71.2 mmol, 1.4M in cyclohexane) at −78° C. was added to 4-chloro-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridine (10.0 g, 32.4 mmol) in THF (100 mL), and the reaction was stirred at −78° C. for 30 minutes. I2 (20.5 g, 80.9 mmol) in THF (50 mL) was added, and the reaction was stirred at −78° C. for 20 minutes. A saturated ammonium chloride solution (50 mL) and a saturated sodium sulfite solution (50 mL) were added, and the mixture was extracted with hexanes (200 mL), washed with brine and dried over sodium sulfate. After removal of the solvent, the residue was dissolved in THF (50 mL), and TBAF (32.4 mL, 32.4 mmol) was added. The reaction was stirred at room temperature for 10 minutes, and then water (20 mL) and ethyl acetate (100 mL) were added. The organic layer was separated, washed with brine, and dried over sodium sulfate. After removal of the solvent, the residue was suspended in dichloromethane (“DCM”; 20 mL) and stirred for 10 minutes. The solid formed was collected by filtration to give 4-chloro-5-iodo-1H-pyrrolo[2,3-b]pyridine (6.6 g, 73% yield) as a solid.

1. stirringthe reaction was stirred at −78° C. for 20 minutes
2. extractionthe mixture was extracted with hexanes (200 mL)
3. washwashed with brine
4. dry with materialdried over sodium sulfate
5. customAfter removal of the solvent
6. dissolutionthe residue was dissolved in THF (50 mL)
7. stirringThe reaction was stirred at room temperature for 10 minutes
8. customThe organic layer was separated
9. washwashed with brine
10. dry with materialdried over sodium sulfate
11. customAfter removal of the solvent
12. stirringstirred for 10 minutes
13. customThe solid formed
14. filtrationwas collected by filtration

ORD record

ord-c599e589bc614477bd8bc63c076567c6

Source dataset

uspto-grants-2014_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08758830B2