GB1278353A - Preparation of dicarboxylic acids - Google Patents

Abstract

1278353 Dicarboxylic acids MONSANTO CO 15 Aug 1969 [15 Aug 1968] 40881/69 Addition to 1234641 Heading C2C Dicarboxylic acids are prepared by reacting non-vicinal glycols (3-20 C), their halogen substituted derivatives, or their ester and ether derivatives with carbon monoxide in a solution containing a rhodium or iridium compound as catalyst with a promotor selected from halogen and halogen compounds at a temperature of from 125‹ to 250‹ C. and where the compound is a derivative of a glycol in which both OH radicals are substituted, water at a temperature of 125‹ to 250‹ C. Glycols, preferably with 2 less carbon atoms than the desired acids, may be, e.g., 1,3- propanediol to yield glutaric acid, or rescorcinol or hydroquinone to yield phthalic acids, and derivatives may be tetrahydrofuran, 1,4-dibromobutane, 1,6-diiodohexane, 1,4-butaneglycol diacetate, 1,3-dibromobutane, 1,4-dichlorobutane; paradiiodobenzene and 1,5-dichlorooctane. The rhodium or iridium compounds may be co-ordination complexes which may include suitable ligands, e.g. complexes of rhodium, carbon monoxide, and iodide. Adipic acid may be prepared using a feedstock with derivatives of butane-1,4-diol such as 1,4-dichlorobutane, 1,4 - dibromobutane, tetrahydrofuran, and combinations thereof.