Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl ester → HCID 72459876, compound

Participants

Reaction Conditions

Reaction Steps

In a 0.3 1 three necked flask fitted with a magnetical stirrer and dropping funnel under inert atmosphere, 6.62 g (20.8 mmol, 1 eq) of 6-bromo-2,4-difluoro-3-(pyrrolidin-1-ylazo)-benzaldehyde a9 are dissolved in THF (100 ml) and cooled down to 0° C. Ethyl (triphenylphosphoranylidene)acetate (9.43 g, 1.3 eq) is then added under efficient stirring, the temperature raising to 10° C. The mixture is kept under stirring one hour at 0° C., and then overnight at room temperature. The mixture is concentrated to dryness, the residue suspended in diethyl ether, the triphenylphospine oxide is filtered off and the filtrate concentrated to dryness. The residue is purified by PrepLC on silicagel (CH2Cl2/pentane: 50/50 (v/v)) to give 4.17 g of pure of 3-[6-bromo-2,4-difluoro-3-(pyrrolidin-1-ylazo)-phenyl]-acrylic acid ethyl ester a10 (47%).

Provenance & Evidence