Patent ID: 7319161

Claim:
A process for preparing an alkyl-substituted or unsubstituted cyclohexane-1,2-dicarboxylic acid, or a mono- or diester or anhydride thereof, comprising the following sequences of steps (1) to (3): (1) Converting a diene/maleic acid anhydride mixture to give alkyl-substituted or unsubstituted cyclohexenedicarboxylic acid anhydride in the condensed phase; (2) Forming an ester from an alkyl-substituted or unsubstituted cyclohexenedicarboxylic acid anhydride; (3) Hydrogenation of the alkyl-substituted or unsubstituted cyclohexene ester of step (2) to give the corresponding ester of cyclohexane; or (1) Converting a diene/maleic acid anhydride mixture to give an alkyl-substituted or unsubstituted cyclohexenedicarboxylic acid anhydride in the condensed phase; (3) Hydrogenation of the alkyl-substituted or unsubstituted cyclohexenedicarboxylic acid anhydride to give cyclohexanedicarboxylic acid anhydride; (2) Forming an ester from the alkyl-substituted or unsubstituted cyclohexanedicarboxylic acid anhydride, and wherein the diene/maleic anhydride mixture for the reaction according to step (1) is a butadiene/maleic acid anhydride mixture which is obtained by a process comprising the oxidation of products containing n-butene or butadiene or a mixture thereof or by a process comprising the oxidation of n-butene to give butadiene or by a process comprising the oxidation of n-butene to give a butadiene/maleic acid anhydride mixture, or wherein the diene/maleic anhydride mixture for the reaction according to step (1) is a mixture of maleic acid anhydride and at least one C5 cut obtained in a crack process and comprising at least one C5 diene.