Synthesis of benzodiazepines catalyzed by chitosan functionalized by triacid imide as a superior catalyst

摘要

Chitosan functionalized by triacid imide has been applied as an effective catalyst for the synthesis of benzodiazepines by one-pot reactions of 1,2-phenylenediamine with dimedone and aryl aldehydes or isocyanides and Meldrum's acid. Chitosan functionalized by triacid imide was confirmed by FT-IR (infrared spectroscopy), XRD (X-ray diffraction), DSC (differential scanning calorimetry) and TGA (thermogravimetric analysis). To investigate the scope and limitation of this reaction, different aryl aldehydes and isocyanides were used as substrates. Good yields in short reaction times, experimental simplicity, extensive range of products, retrieval of the catalyst and low catalyst loading are some of the substantial aspects of this method.