Green synthesis of 1,3-Thiazolidin-4-ones derivatives by using acid-activated montmorillonite as catalyst

An environmentally friendly, clean, and applicable methodology for synthesizing 1,3-Thiazolidin-4-one derivatives was developed. This method produced the target compounds in high yields and short reaction times by using solvent-free reaction conditions with heterogeneous catalysts, montmorillonite (MT) and acid-activated montmorillonite (acid-MT). MT and acid-MT were investigated in the synthesis using a variety of techniques, including conventional heat, ultrasonic, and microwave irradiation, with the investigation of two types of factors, namely time and temperature. X-ray diffraction, N-2 adsorption-desorption, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy were used to characterize the MT and acid-MT catalysts. FTIR, H-1 NMR, C-13 NMR, and mass spectra were used to characterize each product. The ring-cyclization step, with its short time and high yield percentage, is the most important factor for the strength of the prepared catalyst, acid-MT. Additionally, the acid-MT catalyst was easily recoverable and can be reused up to five times without suffering a substantial reduction in catalytic activity.