Investigation on main reaction and side reaction mechanism in the synthetic process of 1-(5-bromothiophen-2-yl)-3-(4-nitrophenyl)prop-2-en-1-one using Raman spectroscopy

Abstract

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.