Hydrogen Peroxide → HCID 178433905, compound

Participants

Reaction Steps

1 g of 3-methyl-1-(4-carboxyphenyl)-5-pyrazolidone (4.5 mmol) was dissolved in 20 ml of methanol and a sufficient amount of nitrogen gas was injected into the solution to replace the air with nitrogen. A catalytic amount of selenium dioxide (25 mg, 0.05 equivalent, MW 110.96) was added and 1.5 ml (3 equivalent) 30% hydrogen peroxide was added dropwise over an ice-cooled water bath. The mixture was stirred until room temperature. The stirring was continued for a further 12 hours while heating at 70-80° C. The deposited crystals were separated by filtration and dried under reduced pressure to obtain 460 mg of 5,5'-dihydroxy-3,3'-dimethyl-1,1'-bis(4-carboxyphenyl)-4,4'-bipyrazole (MW 434.12, 1.06 mmol, 47.1%).

Provenance & Evidence