Oxalic Acid → 2,5-Dimethyl-3-furoic acid

Beteiligte Stoffe

Reaktionsschritte

To a stirred and refluxing solution of ethyl sodioacetoacetate (0.5 mole, 78g.) and sodium iodide (1g.) in dry acetone (250 ml.) was added chloroactone (0.54 mol. 50g.) over a period of ten minutes. After one hour the acetone was distilled from the reaction mixture and the residue was diluted with 400 ml. water. The preciptated oil was extracted with ether and the ether removed to yield the intermediate 3-carbethoxy-2,5-hexanedione (75g.). The intermediate (26.4g.) was cyclized by heating under reflux over 5 g. anhydrous oxalic acid for 11/4 hours. The crude ester was saponified by heating under reflux for 45 minutes with potassium hydroxide (26g.) in methanol (200 ml.). The methanol was removed, the residue dissolved in water and the solution acidified to yield 2,5-dimethyl-3-furoic acid (18g.), m.p. 130°-133°.

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