STUDIES ON THE SYNTHESIS OF DIMETHYL 4-HYDROXY-4’-METHOXY-5,6,5’,6’-BISMETHYLENEDIOXY BIPHENYL2,2’-DICARBOXYLATE——AN ESSENTIAL METABOLITE OF BIPHENYL DIESTER

This paper reports the synthesis of dimethyl 4-hydroxy-4′ -methoxy-5,6,5′, 6′-bis-methylenedioxybiphenyl-2,2′-dicarboxylate (Ⅱ). Various conditions for bromination were tried to findthe best one for synthesis of the key intermediate compound 6. After Ullmann condensation of 6 with8 and hydrogenolysis,the title compound Ⅱ was obtained. It was proved to be identical with the isolat-ed metabolite of biphenyl diester by spectral data.