The liquid phase esterification of phenyl acetic acid with p-cresol over different metal cation exchanged montmorillonite nanoclays yields p-cresyl phenyl acetate. Different metal cation exchanged montmorillonite nanoclays (Mn+ = Al3+, Zn2+, Mn2+, Fe3+, Cu2+) were prepared and the catalytic activity was studied. The esterification reaction was conducted by varying molar ratio of the reactants, reaction time and catalyst amount on the yield of the ester. Among the different metal cation exchanged catalysts used, Al3+-montmorillonite nanoclay was found to be more active. The characterization of the material used was studied under different techniques, namely X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. The product obtained, p-cresyl phenyl acetate, was identified by thin-layer chromotography and confirmed by Fourier transform infrared, 1H NMR and 13C NMR. The regeneration activity of used catalyst was also investigated up to fourth generation.

Nanoclay minerals received considerable importance in the field of material applications and organic synthesis because of natural occurrence, greater surface area, good selectivity, ion exchange properties, economical, functional simplicity, easy modification, and environmental acceptability. The eco-friendly liquid-phase oxidation reaction of benzyl alcohol over modified nanoclays such as metal cation exchanged impregnated nanoclays and surfactant immobilized with oxyanions of Cr(VI) and Mn(VII) yields benzaldehyde. Surfactant immobilized (HDTMA-Cr(VI)/Mn(VII)-MMT-nanoclays) and impregnated M n+-MMT-Cr(VI)/Mn(VII)-nanoclays were prepared and the activity of modified nanoclays were studied. The oxidation reactions were carried out by varying the molar mass of the modified nanoclays with active species, reaction period and amount of catalyst on the yield of benzaldehyde. Surfactant immobilized nanoclays were found to be more active than impregnated nanoclays. The percentage yield of the product was calculated using 2,4-dinitrophenylhydrazine derivative. The materials used for this analysis were examined under different characterization techniques like XRD, SEM and TGA. From the XRD spectra was observed that the interlamellar spacing of montmorillonite nanoclay, Al 3+-MMT-nanoclay, HDTMA-Cr(VI)-MMT-nanoclay and HDTMA-Mn(VII)-MMT-nanoclay were 9.81Å, 9.931 Å, 27.6 Å and 28.0 Å respectively. The superficial area of montmorillonite nanoclay has higher than modified nanoclay which was confirmed by SEM images. The TGA analysis stated that the used nanomaterial is thermally stable. The product obtained, benzaldehyde was indicated by TLC and confirmed by spectral studies like FTIR, 1 H NMR and GC-MS. The activity of regenerated modified nanoclays was studied under standard experimental conditions up to the fourth generation. The result of different solvents on the yield of aldehyde was determined. The materials used are naturally occurring, safe to handle, environmentally friendly and reusable.

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