Formaldehyde → HCID 18677142, compound

Participants

Reaction Steps

A mixture of 1-(4′-nitrophenyl)-3-t-butyl-5-aminopyrazole (I mmol) and formaldehyde (10 mmol, 37% w/w in H2O) in MeOH (7.5 mL) was stirred at rt for 30 minutes. Acetic acid (2.5 mL) and NaCNBH3 (2 mmol) were added, and after 1 hour additional NaCNBH3 (2 mmol) was added. After 1 hour, 1N H2SO4 was added, the solvent was removed and the residue was neutralized with NaHCO3. The solid product was collected by filtration, washed with water and dried to give 1-(4′-nitrophenyl)-3-t-butyl-5-dimethylaminopyrazole (0.265 g, 92%). Transfer hydrogenation of the nitro compound (0.89 mmol) as described in general in Method L gave 1-(4′-aminophenyl)-3-t-butyl-5-dimethylaminopyrazole (0.228 g, 100%).

Provenance & Evidence