Patent ID: 8716532

Claim:
A single step process for the preparation of some multiconjugated hydroxy stilbene derivatives with the general formula 1: wherein, at least one substituent being OH amongst R 1 , R 2 , R 3 , R 5 , R 6 , R 7 , R 8 , R 10 , and rest of substituents amongst R 1 to R 10 , being H, OH, OCH 3 , CH 3 COO, halogen, nitro, CH═CH—COOH, C 6 H 3 -(4-OH,3-OMe), C 6 H 4 —CH═CH—CO—C 6 H 4 -(4-OMe), CH 2 —CH 2 —CH 3 , the said process comprising steps of: (a) refluxing substituted arylaldehyde with at least one hydroxy substituent at 2- or 4-position, malonic acid and halobenzene in the presence of a base, palladium catalyst, triphenylphosphine and a solvent for a period ranging between 30 min-15 hr; (b) transferring the reaction mixture of step (a) in ice cooled water and washing the residue with an organic solvent; (c) washing the organic solution of step (b) with a mineral acid, brine and water; (d) drying the organic layer of step (c) over a dehydrating agent, followed by filtering and evaporating to dryness to completely remove the solvent to obtain a residue; (e) purifying the residue of step (d) on Si-gel (60-120 mesh size) with a mixture of ethylacetate and hexane (9:1 to 6:4) to obtain the required substituted hydroxy stilbene of general formula 1.