| 摘要 |
To prepare aromatic carbonates of the formula (I) <IMAGE> in which R and R<1> have the meaning given in Patent Claim 1, or to prepare bis-methyl carbonate, or bis-ethyl carbonate, of bisphenol A, corresponding phenols or their acyl esters are reacted with equally corresponding dialkyl carbonates or arylalkyl carbonates in the presence of Lewis acids or compounds of metals which can form Lewis acids, as catalysts. The resulting bis-methyl carbonate, or bis-ethyl carbonate, of bisphenol A is used for the preparation of polymeric carbonates of bisphenol A. Here, dimethyl carbonate, or diethyl carbonate, is eliminated from the bisphenol A bis-methyl carbonate, or bis-ethyl carbonate, by heating. The novel process uses no toxic compounds, the reaction proceeds relatively rapidly, and good conversion rates and a high selectivity are achieved. |
