How is 2-Ethoxy-3,3-dimethyl-2,3-dihydro-1-benzofuran-5-yl methanesulfonate (CAS: 26225-79-6) typically synthesized?

2-Ethoxy-3,3-dimethyl-2,3-dihydro-1-benzofuran-5-yl methanesulfonate is usually synthesized through the methylation of 2-ethoxy-3,3-dimethyl-2,3-dihydro-1-benzofuran-5-carboxylic acid with methanesulfonyl chloride in the presence of a suitable base. The reaction is typically carried out at room temperature with high selectivity and yields over 90%. The use of a phase transfer catalyst can further enhance the efficiency of the synthesis.