Process for preparation of substituted aromatic compound employing friedel-crafts reaction using a reusable basic anionic clay catalyst

摘要

A process for Friedel-Crafts type liquid-phase alkylation or acylation of an aromatic compound using a hydrotalcite-type basic anionic clay catalyst represented by a formula:; $PTEXTPDAT\[(M/PDATHILSPPDAT2\+/PDAT/SP/HILPDAT)/PDATHILSBPDAT1\−x/PDAT/SB/HILPDAT(M/PDATHILSPPDAT3\+/PDAT/SP/HILPDAT)/PDATHILSBPDATx/PDAT/SB/HILPDAT(OH)/PDATHILSBPDAT2/PDAT/SB/HILPDAT\]/PDATHILSPPDATx\+/PDAT/SP/HILPDAT\[A/PDATHILSPPDATy\−/PDAT/SP/HILPDAT\]/PDATHILSBPDATx/y\; /PDAT/SB/HILHILITALICPDATq\; /PDAT/ITALIC/HILPDATH/PDATHILSBPDAT2/PDAT/SB/HILPDATO/PDAT/PTEXT$ ;where;M^2+ is a divalent cation selected from Mg^2+, Zn^2+, Ni^2+, Co^2+, Mn^2+, Cu^2+ or a mixture thereof,;M^3+ is a trivalent cation selected from Ga^3+, In^3+ Al^3+, Fe^3+ Cr^3+ or a mixture thereof; x is a mole fraction of trivalent cations in the range of about 0.05 to about 0.5; O is oxygen; H is hydrogen; A^y− is an anion; y minus is an anionic negative charge having a value of 1 minus or 2 minus; and q is a number of water molecules, as the water of hydration; and involving following steps:;i. pretreating said catalyst by contacting it with a halogen containing compound in the presence or absence of a non-aqueous solvent and optionally washing the pretreated catalyst with non-aqueous solvent or liquid aromatic compound to be alkylated or acylated; and then;ii. contacting a liquid reaction mixture comprising said aromatic compound and said alkylating or acylating agent in the presence or absence of a non-aqueous solvent with the catalyst obtained from step (i) in a stirred batch reactor fitted with a reflux condenser under vigorous stirring, in the presence or absence of an inert gas bubbling through the reaction mixture, at effective reaction conditions;;iii. cooling the reaction mixture to a temperature about 30° C., removing said catalyst from the reaction mixture by filtration and then separating the reaction products from the reaction mixture, and optionally washing the used catalyst by non-aqueous solvent; and if desired,;iv. reusing the used catalyst directly with or without drying for the subsequent reaction batch avoiding step (i), is disclosed.