Preparation of substituted aromatic carboxylic acid esters

A one-pot process for the preparation of a thioether-substituted aromatic carboxylic acid ester comprising the steps of:

• reacting a nitro-substituted aryl halide, in the absence of water and oxygen, with carbon monoxide and an alcohol in the presence of a metal catalyst and a proton acceptor to form the corresponding nitro-substituted aromatic carboxylic acid ester;
• wherein:
• said aryl group of said nitro-substituted aryl halide is a substituted or unsubstituted, monocyclic or polycyclic aryl group or heteroaryl group containing at lest one heteroatom of N, O, or S;
• said carbon monoxide is present at a pressure of 1.47-1100 psi;
• said alcohol is a linear or branched, substituted or unsubstituted C1-C5 alkyl alcohol;
• said proton acceptor is a tertiary amine base;
• and
• said metal catalyst is a heterogeneous catalyst of palladium metal deposited on activated carbon present in an amount of between about 1 weight percent and 500 weight percent based on said nitro-substituted aryl halide, and
• reacting without isolating said corresponding nitro-substituted aromatic carboxylic acid ester with thiolate anion to form the corresponding thioether-substituted aromatic carboxylic acid ester.