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

[Display omitted] •Acid-activated montmorillonite was used as heterogeneous catalysts to produce 1,3-Thiazolidin-4-ones derivatives.•As a green and economical methodology, the acid-activated montmorillonite demonstrated optimal catalytic activity for the one-pot synthesis of 1,3-thiazolidin-4-ones under solvent-free microwave irradiation conditions with excellent yield.•Microwave irradiation enhanced the reactivity of the catalyst.•The catalytic activity of the Acid-MT catalyst doesn't significantly decrease after being employed up to five times. 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, N2 adsorption–desorption, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy were used to characterize the MT and acid-MT catalysts. FTIR, 1H NMR, 13C 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.