3,4-Dichlorobenzaldehyde → HCID 68828353, compound

Participants

Reaction Conditions

Reaction Steps

Alternatively, the Bignelli reaction was carried out in two steps with higher yields. To 1-(pyrrolidin-1-ylsulfonyl)propan-2-one in THF was added an equivalent amount of 3,4-dichlorobenzaldehyde and a catalytic amount of titanium tetraisopropoxide. The reaction was stirred at 80° C. overnight. Solvent was removed and the residue was purified by silica flash chromatography (0% to 15% ethyl acetate-hexanes) to provide 4-(3,4-dichlorophenyl)-3-(pyrrolidin-1-ylsulfonyl)but-3-en-2-one. The product obtained was dissolved in 1,4-dioxane and one equivalent of 3-methyl-1H-pyrazol-5-amine was added. The reaction was stirred at 80° C. for 24-48 hrs. Solvent was removed and product was obtained after flash chromatography (silica gel, 0% to 40% ethyl acetate-hexanes).

Provenance & Evidence