Emodin-5-methyl ester

Polygonum multifolrum Thunb. P. chinensis L. He Shou Wu Huo Tan Mo Cao (Hill buckwheat) (root, stem, leaf) Chrysophenol, emodin, emodin methyl ester, rhein, glycoside rhaphantin, lecithin, parietin, chrysophanic acid, anthron.33-49-54-442 A laxative, detoxicant for boils. Treat neurosis, neurasthenia, insomnia, hypercholesterolemia. 

A new synthesis of emodin has been reported 165) (Scheme 17). Thus the Friedel-Crafts acylation of methyl 3,5-dimethoxybenzoate with 2-methoxy-4-methylbenzoyl chloride followed by hydrolysis of the ester yielded the benzophenone (160). Cyclisation and demethylation was accomplished by treating (160) with an aluminium chloride-sodium chloride melt yielding emodin (161). 

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