Phenol is industrially produced by the Hock process, in which cumene hydroperoxide (CHP) is decomposed with sulfuric acid to obtain equimolar amounts of phenol and acetone. Use of the liquid acid requires subsequent neutralization and purification of the phenol at substantial cost, and a waste stream generation that could be avoided if an effective solid acid catalyst could be used. Modified clays exhibit attractive properties as solid acids. Acid treatment produces an increase in surface area and acidity. The present study was undertaken to modify bentonite clay by treatment with hydrochloric acid for the production of phenol and acetone via the decomposition of cumene hydroperoxide. The effects of various parameters such as acid activation, catalyst weight, concentration of CHP, reaction temperature and reusability of catalyst were studied. The results indicate that the acid-modified bentonite catalyst may be used instead of sulfuric acid for selective decomposition of CHP into phenol and acetone.
In this paper, the application of cerium modified nanocrystalline zeolite ZSM-5 as catalyst for Friedel Crafts acylation of toluene was investigated and compared with nanocrystalline ZSM-5. The acylating agent used was acetic anhydride. The zeolite samples were characterized by means
of Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), Thermal analysis, ammonia temperature-programmed desorption (NH3-TPD) and Nitrogen sorption analysis. The results
show an enhanced Lewis acidity, pore volume and surface area for cerium modified ZSM-5 providing a superior accessibility for acetic anhydride and toluene to the active sites compared to the unmodified one, thereby leading to 93% conversion of acetic anhydride, which was higher than that of
unmodified ZSM-5 sample.
A broad range of aldehydes undergo a smooth cascade cyclization with (E)-5-(3-phenylprop-2-ynylamino)pent-3-en-1-ol in the presence of BF·OEt at room temperature to furnish a novel series of (octahydro-1H-pyrano[3,4-c]pyridin-5-yl)methanone derivatives in good yields and diastereoselectivities. This cascade process provides a simple and proficient alternative for the stereoselective construction of fused pyranopiperidine derivatives.
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