Highly selective synthesis of nopol over mesoporous and microporous solid acid catalysts

Prins condensation of β-pinene was carried out with paraformaldehyde in the presence of toluene as solvent over mesoporous Zn-Al-MCM-41 catalysts under liquid phase reaction conditions for synthesis of nopol. The influence of various reaction parameters, such as reaction temperature, time, ratios of reactants and recyclability have been investigated. The catalytic results were also compared with those obtained using Al-MCM-41, HY, Hβ, H-mordenite and H-ZSM-5 zeolites. Zn-Al-MCM-41(75) is then found to be a highly active and recyclable heterogeneous catalyst for selective synthesis of nopol. Furthermore, Zn-Al-MCM-41(75) has higher selectivity of nopol than other Zn-Al-MCM-41, Al-MCM-41, HY, Hβ, H-mordenite and H-ZSM-5.

Graphical abstractA novel mesoporous Zn-Al-MCM-41 is found to be a highly active and recyclable heterogeneous catalyst suitable for the selective synthesis of nopol by Prins condensation of β-pinene and paraformaldehyde in toluene having much higher acidity and activity than other catalysts, such as Al-MCM-41, USY, Hβ, H-ZSM-5 and H-mordenite. Figure optionsDownload full-size imageDownload as PowerPoint slide