1211443-58-1

1211443-55-8

1211443-58-1

2-Chloro-7-cyclopentyl-7H-pyrrolo[2,3-d]pyrimidine-6-carboxaldehyde (2.69 g, 11 mmol) was used as starting material and dissolved in DMF. Subsequently, Oxone (7.2 g, 12 mmol) was added to this solution and the reaction was stirred at room temperature for 6 hours. After completion of the reaction, water was added to the reaction mixture to precipitate the target product. The yellow solid, 2-chloro-7-cyclopentyl-7H-pyrrolo[2,3-d]pyrimidine-6-carboxylic acid (2.69 g, 85% yield) was collected by filtration. Mass spectrum (ESI) m/z 266 [M + H]+.