Coordinative Role of Alkali Cations in Organic Reactions.V. The Perkin Reaction

Article abstract of DOI:10.1246/bcsj.53.3338

The Perkin condensation of benzaldehyde (PhCHO) and acetic anhydride (Ac2O) in the presence of an alkali acetate (M⁺OAc^-) involves extensive participation of M⁺ and take place best with K⁺OAc^-.Employing an excess of meticulousy dehydrated K⁺OAc^-, a record high yield of cinnamic acid (ca.75percent) can be obtained in a 60 min reaction.The product of the reaction before hydrolysis is not PhCH=CHCOOCOCH3 as usually believed but potassium cinnamate plus K⁺(OAc,HOAc)^-.Conductometric solution stability studies on M⁺-ligand (M⁺=Na⁺ and K⁺; Ligand=PhCHO, o-NO2C6H4CHO,o-HOC6H4CHO) systems in 2-propanol show that stabilty sequences for PhCHO and o-NO2C6H4CHO are NaOAc+OAc^- in 2-propanol.