| 摘要 |
<p>The present invention is to provide a process for producing piperonal which comprises continuous three steps of: (A) an addition reaction step wherein 1,2-methylenedioxybenzene and glyoxylic acid are reacted to form 3,4-methylenedioxymandelic acid in the presence of a strong acid, (B) an extraction step wherein an organic solvent is then added to a reaction mixture and the mixture is neutralized with a base to extract 3,4-methylenedioxymandelic acid in an organic solvent layer, and separating the organic solvent layer and an aqueous layer, and (C) an oxidation reaction step wherein the aqueous layer is removed and the organic solvent layer is concentrated, and then, nitric acid is added to a concentrate, and the 3,4-methylenedioxymandelic acid and nitric acid are reacted to form piperonal.</p> |
