Potassium and Sodium 2,6-Di-tert-Butyl Phenoxides and their Properties

Abstract

The determining factor of the reaction of 2,6-di-tert-butylphenol with alkaline metal hydroxides is temperature, depending on which two types of potassium or sodium 2,6-di-tert-butyl phenoxides are formed with different catalytic activity in alkylation of 2,6-di-tert-butylphenol with methyl acrylate. More active forms of 2,6-But2C6H3OK or 2,6-But2C6H3ONa are synthesized at temperatures higher than 433 K representing predominantly monomers of 2,6-di-tert-butylphenoxides which produce dimers when cooling. The data of NMR 1Н, electronic, and IR spectra for the corresponding forms of 2,6-But2C6H3OK and 2,6-But2C6H3ONa isolated in the individual state showed a cyclohexadienone structure. In DMSO or DMF media the dimeric forms of 2,6-di-tert-butylphenoxides react with methyl acrylate to form methyl 3-(4-hydroxy-3,5-di-tert-butylphenyl) propionate with 64–92 % yield.