N-Iodosuccinimide → 6-Chloro-7-iodo-7-deazapurine

Participants

Reaction Steps

Dissolve 6-chloro-7-deazapurine (10.75 g, 70 mmol) and N-iodosuccinimide (16.8 g, 75 mmol) in 400 mL of dry DMF and leave at ambient temperature in the darkness over night. Evaporate the solvent. Distribute the dark residue between 500 mL of ethyl acetate and 150 mL of 10% Na2SO3. Wash the organic fraction with 10% Na2SO3 (2×100 mL), saturate aqueous sodium chloride solution (150 mL), dry over Na2SO4 and evaporate. Crystallize the yellow residue from ethanol to yield 16.2 g (83%) of 4-chloro-5-iodo-7H-pyrrolo[2,3-d]pyrimidine as off-white crystals. Evaporate the mother liquor, dissolve in toluene, and purify by flush chromatography on silica gel (7×4 cm). Wash the column with toluene until the eluant is colourless then elute the title compound with 5% ethyl acetate in toluene to give an additional 3.5 g of the product.

Provenance & Evidence