To enable to obtain in high yield a stilbenediol capable of treating wastes simply and useful for organic syntheses by dehydration-condensing a specific phenol with a specific carbonyl compound and reacting the produced precursor with a base without isolating the precursor.
This production method of a stilbenediol is to bring a phenol (A) having OHs at ortho and para positions and a carbonyl compound (B) having a halogen at α position such as chloroacetaldehyde to a dehydration-condensing reaction in the presence of an organic solvent such as methyl isobutyl ketone and a catalyst such as surfulic acid and phosphoric acid, produce a compound of formula I [X is a halogen; R1 and R2 are each X or a 1-6C hydrocarbon group; R3 is H or R1; (i) and (j) are each 0-4], obtain a mixture separated into an organic phase (Z1) containing the compound and a water phase (Z2), separate the Z1 from the mixture, react a base such as NaOH to Z1 and obtain the objective compound of formula II. The acid catalyst is preferably used in 1.2-8.0 equivalent ration based on the ingredient B.
YOKOTA AKIRA
HIRANO YASUHIRO
ENDO YASUHIRO
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