Solubility of androstenedione in lower alcohols

Androstenedione (AD) solubilities in methanol, ethanol, 2-propanol, and 1-butanol were measured from 277.65 K to 319.45 K with medium-throughput experiments. The results show that AD solubilities increase with increasing temperature and solvent polarity. The experimental data are well correlated by modified Apelblat, λ h , Margules, Wilson, NRTL, and UNIQUAC models, and the NRTL model obtains the best fitting results. The thermodynamic functions (i.e., Gibbs free energy, enthalpy, and entropy of solution and mixture) are calculated using the van’t Hoff and NRTL equations. Molecular interaction energies between AD and alcohols are calculated by COSMO-RS to investigate the effects of temperature and solvent polarity on AD solubility, and predicted AD solubilities in different alcohols agree well with the experimental data. The results suggest that temperature influence on AD solubility is driven by cavity formation enthalpy, whereas hydrogen bonding and electrostatic interactions between AD and alcohol molecules play a key role in solvent polarity effect on AD solubility.