Triphenylphosphine → 1-(1-benzyl-4-piperidinyl)-3-bromo-4-chloro-1H-pyrazolo[3,4-d]pyrimidine

Participants

Reaction Steps

3-bromo-4-chloro-1H-pyrazolo[3,4-d]pyrimidine (Intermediate B) (5.0 g, 21.42 mmol), 1-benzyl-4-piperidinol (8.2 g, 42.83 mmol) and triphenylphosphine (11.23 g, 42.83 mmol)were suspended in 250 ml of tetrahydrofuran. The reaction mixture was cooled in an ice-water bath and diethyl azodicarboxylate (6.8 ml, 42.83 mmol) was added dropwise. 10 minutes later, the reaction mixture was allowed to warm up to room temperature. After stirring for 2 hours, solvent was removed and the residue was taking into ethyl acetate. The organic layer was washed, dried and evaporated. The crude product was passed through Biotage flash column using dichloromethane/ethyl acetate (90:10) as the mobile phase to yield 10.56 g of 1-(1-benzyl-4-piperidinyl)-3-bromo-4-chloro-1H-pyrazolo[3,4-d]pyrimidine. The product was 61% pure with a HPLC retention time of 12.46 min. (HPLC condition: 5 to 95% CH3CN in 0.1 N aqueous ammonium acetate over 20 min., the column size is 3.9×150 mm, 300 A).

Provenance & Evidence