190430-39-8

Upstream product

• 4330-21-6 2-deoxy-3,5-di-O-p-toluoyl-α-D-erythro-pentofuranosyl chloride 
• 190430-36-5 3-bromo-4-methoxy-1H-pyrazolo[3,4-d]pyrimidine 
• 5399-93-9 4-methoxy-1H-pyrazolo[3,4-d]-pyrimidine 

Downstream Products

• 95087-07-3 2-[2-deoxy-3,5-di-O-(p-toluoyl)-β-D-erythro-pentofuranosyl]-4-methoxy-2H-pyrazolo[3,4-d]pyrimidine 

Relevant academic research and scientific papers

Unexpected dehalogenation of 3-bromopyrazolo[3,4-d]pyrimidine nucleosides during nucleobase-anion glycosylation

The anion-glycosylation (KOH, MeCN, TDA-1) of 3-bromopyrazolo[3,4-d]- pyrimidines 4a and 4b with 2-deoxy-3,5-di-O-(p-toluoyl)-α-D-erythro- pentofuranosyl chloride (5) furnishes the regioisomeric N1-β-D-2'- deoxyribonucleosides 6a and 6b together with the dehalogenated N2- regioisomers 8a and 8b, stereoselectively. The dehalogenation takes place after the glycosylation and results from the sensitivity of the N-2 nucleosides toward aqueous base. An addition/elimination mechanism is suggested for the dehalogenation reaction.