Solubility of Benzanilide Crystals in Organic Solvents

The solubility of benzanilide in sixteen pure organic solvents, including N, N-dimethylformamide, tetrahydrofuran, butanone, acetone, ethyl acetate, dichloromethane, n-butanol, diethyl ether, n-propanol, acetonitrile, ethanol, methanol, isobutanol, isopropanol, toluene, and carbon tetrachloride, was measured at temperatures ranging from 274.15 to 313.15 K using the static equilibrium method at atmospheric pressure. The modified Apelblat model, Buchowski-Ksiazczak λh model, and Non Random Two Liquid (NRTL) model were used to correlate the experimental solubility data. It was found that in all these solvents the solubility of benzanilide increases in different pace as the temperature increases. The modified Apelblat model gave the best fit. Guided by the solubility data, preliminary experimental study was conducted for cooling crystallization of benzanilide in ethanol and n-propanol. The result indicated that the solvent, stirring speed and cooling rate all have significant impact on crystal morphology and particle size distribution.