Study On The Synthesis Of5-Substitiuted Resorcinol Derivatives

Alkyl substituted resorcinols is a very important intermediatechemical and widely used in the synthetic chemical industry.3,5-dihydroxy amylbenzene is the important component of most drugswidely distributed in plants due to its various biological activities.In this paper,3,5-dihydroxyamylbenzene was prepared by a four-stepsway.3,5-dimethoxybenzoyl chloride was obtained by chlorination of3,5-dimethoxybenzoic acid and then reacted with n-butylmagnesiumbromide to give3,5-dimethoxyphenylpentan-1-one.3,5-dimethoxyphenyl-pentane was prepared through the Huang-Minlon reduction of3,5-dimethoxyphenylpentan-1-one and after the demethylation3,5-dihydroxy amylbe-nzene was synthesized. The formation of3,5-dimethoxyphenylpentan-1-one was investigated and the better yield was obtained with theexperimental conditions: the feeding amount of3,5-dimethoxybenzoylchloride is5mmol, the feed ratio of3,5-dimethoxy benzoyl chloride: Mg:BuBr is1:1.8:1.5（molar ratio）,12mL of THF is used as a solvent, thereaction time is12hours, and the temperature of reaction is5°C. Allcompounds were characterized by1NMR and mass spectrometry.In addition, the acylation cleavage of ether bonds was studied. Thereaction of3,5-dimethoxy benzoyl chloride with ether in the presence ofLewis acid to obtain ethyl3,5-dimethoxy benzoate was used as a model reation to survey the reaction parameters. The best Reaction process wasobtained and when3,5-dimethoxy benzoyl chloride is5mmol,0.75equivalent ZnCl₂is used,10mL of ether is used as a solvent, the reactiontime is12hours, and the reaction temperature is25°C. Then,12aromatic ester were synthesized with different acyl chlorides and ethers andall compounds were characterized by1NMR and MS.