In this research, a new polymorph of florfenicol (form B) was discovered and successfully prepared. The new polymorph was characterized and identified by powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) techniques. It was found that form A has lower melting temperature while higher fusion enthalpy. The solubility of both florfenicol polymorphs in methanol, 2-propanol, acetone, acetonitrile, ethanol, and ethyl acetate were experimentally determined from 278.15 to 318.15 K with a dynamic method. For all tested solvents, the solubility data of florfenicol form B are higher than those of form A. The modified Apelblat model, the NRTL model, and the λh model were adopted to calculate the solubility of florfenicol two forms with satisfactory correlation results. In addition, the dissolution thermodynamic properties of florfenicol form A and form B, including dissolution enthalpy, dissolution entropy, and Gibb's dissolution energy in all tested solvents, were obtained. Combining the results of DCS determination, the solubility, and all the dissolution thermodynamic data, it was confirmed that florfenicol polymorph A and polymorph B belong to the enantiotropic polymorph system.
1-(5-Bromothiophen-2-yl)-3-(4-nitrophenyl) prop-2-en-1-one (BTNP) has unique and highly attractive properties, which make them a new kind of nonlinear optical (NLO) organic material for wide applications in the fields of optical communication and flat panel display. In this work, BTNP was successfully synthesized by Claisen−Schmidt condensation reaction. To optimize the synthesis process and improve the purity of the product, the synthetic process of BTNP was monitored in situ by Raman spectroscopy to find out the mechanism of main reaction and possible side reactions. The possible side reactions were proposed based on Raman spectroscopy data. The effect of reaction conditions, including dosage of sodium hydroxide and reaction temperature, was investigated and analyzed by using the proposed side reaction scheme. It was found that the sodium hydroxide dosage is the key factor for the main reaction (Claisen−Schmidt condensation reaction) and side reactions. The effect of reaction conditions on the purity of the obtained BTNP products was investigated and analyzed. The results are consistent with those of proposed side reactions. The purity of the obtained product can reach 96.88% under optimized experimental conditions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.