'AN IMPROVED PROCESS FOR THE CARBONYLATION OF METHANOL BY RHODIUM COMPLEXES OF P,O DONOR LIGANDS',

摘要

An improved process for the preparation of acetic acid and methyl acetate by carbonylation of methanol with carbon monoxide in presence of rhodium carbonyl complexes of ligands selected from the ortho-substituted -OCH3 and -CH2OCH3 groups on the aryl ring of the triphenylphosphine ligands has been developed. The new rhodium complexes [Rh(CO)Cl(2-Ph2PC6H40Me)]5 [Rh(CO)Cl(2-Ph2PC6H4CH2OMe)], trans-[Rh(CO)C1(2-Ph2PC6H4CH2OMe)2], and the reported trans-[Rh(CO)C1(2-Ph2PC6H4OMe)2] have been prepared by stirring a solution of chlorobridged dimeric complex [Rh(CO)2Cl]2 in dichloromethane with appropriate molar equivalent of the ligands 2-Ph2PC6H40Me and 2-Ph2PC6H4CH2OMe respectively under nitrogen atmosphere at 25 °C for 15 - 60 min. Carbonylation of methanol in presence of new and novel rhodium carbonyl complexes catalysts under CO pressure (14-35 bar) at the temperature 130 °C for a period of 1 h produces a mixture of acetic acid and methyl acetate (total conversion in the range 36 - 94 % ) with Turn Over Frequency (TOF) in the range 689 - 1808 h-1. The catalytic activity of the chelate complexes is higher than the non-chelate complexes.[IN-DEL-2010-00681A]