To obtain the subject composition that contains a novel coumarin derivative as an active ingredient and is useful for treatment or prevention of diabetes as a hypoglycemic.
The objective composition contains, as an active ingredient, about 1-70wt.% of a coumarin derivative of formula I (R1 is a hydrogen atom, an alkyl, an alkoxy; R2 is an alkyl, a phenylalkyl, a carboxyalkyl, an alkoxycarbonylalkyl), typically 3-[methyl(diethyl-phosphoromethyl) sulfonio]coumarin-4-olate. The coumarin derivative of formula I is prepared, for example, by allowing a compound of formula II to react with iodobenzene diacetate in the presence of an alkali, for example, sodium carbonate in a solvent (water), then allowing the resultant compound of formula III to react with a thioether derivative of the formula: R2-S-R3 in the presence of an acidic catalyst (acetic acid) in a solvent (methanol).
KAWAMURA KENICHI
HASHIMOTO KINJI
INOUE YASUHIDE
SATO KEIGO
MIKI SHINYA
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