Hydrogen Bromide → 2-Bromo-1-[7-(toluene-4-sulfonyl)-7H-pyrrolo[2,3-d]pyrimidin-4-yl]-ethanone

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Reaction Steps

[5.95 g, 18.88 mmol] of 1-[7-(Toluene-4-sulfonyl)-7H-pyrrolo[2,3-d]pyrimidin-4-yl]-ethanone was dissolved/suspended in 90 mL of glacial acetic acid and [7.53 mL, 10.197 g, 37.76 mmol] of 30% hydrogen bromide in acetic acid. Added dropwise to this stirring mixture at ambient temperature, was [0.970 mL, 3.02 g, 18.88 mmol] of bromine in 10 mL of glacial acetic acid over 1.0 hour. The reaction was stirred an additional 4.0 hours at ambient temperature during which time a yellow precipitate forms. The solvent was removed under reduced pressure and the residue was partitioned between dichloromethane and saturated sodium hydrogen carbonate solution. The organic phase was washed with water, brine, and dried with anhydrous sodium sulphate and the solvent was removed under reduce pressure. The crude solid was triturated/stirred with MTBE overnight and the solid isolated via suction filtration and airdried to yield 4.2 g of pale yellow solid, a 56.6% yield.

Provenance & Evidence