| 摘要 |
NEW MATERIAL:The compound of formula I (R is methyl, ethyl or propyl). EXAMPLE:2,3-Oxomethylenedioxy-2',3'-methylenedioxy-4,4'-dimethoxy-6'-m etho xycarbonyl-1,1'-biphenyl-6-carboxylic acid. USE:It has remedying effect against hepatic disorder and is effective in remedying chronic hepatitis, acute hepatitis, etc. It is also useful as a synthetic intermediate for a biphenyl derivative having asymmetric structure. PREPARATION:The objective compound of formula I can be produced by reacting the compound of formula II with lead tetraacetate and reacting the resultant compound of formula III with acetic acid. The starting compound of formula II is obtained by selectively alkylating one of the meta-OH of an alkyl gallate, converting the remaining two OH to methylenedioxy by reacting diiodomethane in the presence of a base, brominating the 2-position and subjecting the bromination product to Ullmann reaction.
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