Polymorphs of Curcumin and Its Cocrystals With Cinnamic Acid

YesWe report formation of polymorphs and new eutectics and cocrystals of curcumin, a sparingly water-soluble active component in turmeric, structurally similar to cinnamic acid. The curcumin polymorphs were formed using liquid antisolvent precipitation, where acetone acted as a solvent and water was used as the antisolvent. The metastable form 2 of curcumin was successfully prepared in varied morphology over a wide range of solvent-to-antisolvent ratio and under acidic pH conditions. We also report formation of new eutectics and cocrystals of curcumin with cinnamic acid acting as a coformer. The binary phase diagrams were studied using differential scanning calorimetry and predicted formation of the eutectics at the curcumin mole fraction of 0.15 and 0.33, whereas a cocrystal was formed at 0.3 mole fraction of curcumin in the curcumin–cinnamic acid mixture. The formation of the cocrystal was supported with X-ray powder diffraction, the enthalpy of fusion values, Fourier-transform infrared spectroscopy, and scanning electron microscopy. The hydrogen bond interaction between curcumin and cinnamic acid was predicted from Fourier-transform infrared spectra, individually optimized curcumin and cinnamic acid structures by quantum mechanical calculations using Gaussian-09 and their respective unit cell packing structures

Solubilization of benzyl chloride and rate enhancement of its hydrolysis reaction in aqueous sodium cumenesulfonate solutions

Alkaline hydrolysis of benzyl chloride (BzCl) in aqueous solutions of sodium cumenesulfonate (NaCS) is investigated for the hydrotropic effect. The presence of the hydrotrope, NaCS, increased the solubility of BzCl in aqueous solutions by an order of magnitude and consequently the rates of the reaction by 6-fold as compared to those in water. In addition, the hydrotropic medium increased the selectivity toward the formation of dibenzyl ether. Both of these effects have been attributed to the increased solubilization of BzCl, the microenvironment experienced by the reactants in the hydrotrope aggregates and proximity of the reactants for the subsequent condensation reaction