4-Methoxybenzylamine → N-benzyl-1-(6-chloro-3-iodo-1-trityl-1H-pyrazolo[4,3-c]pyridin-4-yl)propan-2-amine

Participants

Reaction Steps

6-chloro-3-iodo-trityl-1H-pyrazolo[4.3-c]pyridine (Intermediate 1C, 2 g, 3.73 mmol), N, N dimethylacetamide-dimethyl acetal (DMA-DMA) (4.97 g, 37.3 mmol) were stirred at 125° C. for 12 hrs. Reaction was concentrated and excess DMF-DMA azeotroped with Toluene. The resulting intermediate and p-methoxybenzylamine (2.05 g, 14.9 mmol) were stirred in a 3:1:1 solution of DCE:AcOH:EtOH (20 ml) at 85° C. for 3 hrs. Solvent was removed by vacuum and the residue was taken in DCE (15 ml) followed with addition of sodium triacetoxyborohydride (3.16 g, 14.9 mmol) and acetic acid (0.9 g, 14.9 mmol) before the mixture was stirred at room temperature for 6 hours. The reaction mixture was partitioned between DCM and aqueous sodium bicarbonate and the organics was separated, washed with brine, dried with sodium sulfate and concentrated. Purification of the residue by flash column (0-90% -EtOAc-hexanes) gave N-benzyl-1-(6-chloro-3-iodo-1-trityl-1H-pyrazolo[4,3-c]pyridin-4-yl)propan-2-amine MS ESI calc'd. for C35H30ClIN4 [M+H]+ 700. found 700.

Provenance & Evidence