Methylsinomeninic acid

Methylsinomeninic acid [xci, R = H] and 1-bromomethylsinome-ninic acid [xci, R = Br] are formed when methylsinomeninone [73] and 1-bromomethylsinomeninone [44] respectively are oxidized with hydrogen peroxide. Similarly the oxidation of 1-bromosinomeneine ketone [lxxvi] affords 1-bromosinomeneinic acid [xcii] [73]. The ultraviolet absorption spectra of [xc, R = H], [xc, R = Br], and [xci, R = H] are very similar to that of sinomenine hydrate, which in turn is almost identical with that of sinomenine [73]. 

Methylsinomeninic acid [xci, R = H] gives the acid chloride on treatment with thionyl chloride and this is converted into the imide by ammonia. On heating with acetic anhydride [xci, R = H] gives not the anhydride but methyldihydrosinomenilone (see below) [75],... 

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