HCID 17978859, compound → HCID 17978866, compound

Participants

Reaction Steps

8.0 g (31 mmol) of 5-amino-1-(4-methoxyphenyl)4-nitrosopyrazole hydrochloride from Step 1.2 in 200 mL of ethanol was hydrogenated for 6 hours on 0.8 g of Pd/C (10%) at 8 bar of hydrogen pressure. The catalyst was filtered off, and the reaction mixture was concentrated to a total volume of about 30 mL. After the addition of 40 mL of 3-molar ethanolic hydrochloric acid and agitation in an ice bath, the product crystallized. Suction filtration and washing with 50 mL of ethyl acetate gave 7.4 g (27 mmol), 86% of the theoretical) of 1-(4-methoxyphenyl)-4,5-diamino-1H-pyrazole dihydrochloride.

Provenance & Evidence