Hydrochloric Acid → HCID 178526711, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-nitro-1H-pyrazole-5-carboxylic acid (4.71 g, 30 mmol), BH3/THF (75 mL, 1 mol/L, 75 mmol) was stirred at 60° C. for 2 h. The mixture was cooled to room temperature and 4M HCl (19 mL, 75 mmol) was added. It was stirred at 70° C. for 2 h. After cooling down to room temperature, the mixture was concentrated under reduced pressure. The residue was partitioned between ethyl acetate and brine (100:100 mL). The aqueous phase was extract with ethyl acetate (4×50 mL). The combined organic layer was dried on Na2SO4 and evaporated under reduced pressure. The residue was purified by silica-gel column chromatography eluting with petroleum ether/ethyl acetate (5:1 to 1:1) to afford 139a (3.5 g, 79%) as a white solid. MS-ESI: [M+H]+ 144.2

Provenance & Evidence