923282-39-7

314021-93-7

923282-39-7

Procedure for the synthesis of compound 9: To a 10 mL solution of thionyl chloride of 1-methyl-1H-pyrazolo[4,3-d]pyrimidin-7-ol (8, 0.835 g, 5.5 mmol) was added 0.5 mL of N,N-dimethylformamide (DMF). The reaction mixture was heated to 90 °C under nitrogen protection with continuous stirring for 1 hour. Upon completion of the reaction, the mixture was cooled to room temperature and the solvent was subsequently removed by distillation under reduced pressure. Water was added to the resulting residue and extracted with dichloromethane (3 x 10 mL). The organic phases were combined, dried over anhydrous magnesium sulfate (MgSO4), filtered and concentrated under reduced pressure to afford 7-chloro-1-methyl-1H-pyrazolo[4,3-d]pyrimidine (9, 0.94 g, 100% yield). The product was detected by electrospray mass spectrometry (ES-MS) and showed m/e = 169 ([M + H]+).