3-(3,4-Dimethoxyphenyl)propionic acid → 5,6-Dimethoxy-1-indanone

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Reaction Steps

Further, Patent Document 1 discloses that 300 g of 3-(3,4-dimethoxyphenyl)propionic acid and 1500 g of polyphosphoric acid were reacted at 65° C. for 30 minutes under a nitrogen atmosphere. The reaction mixture was then cooled, to which 2000 mL of deionized water was then gradually added. The mixture was then stirred at room temperature for two hours and then extracted with 600 mL of chloroform six times. The organic layer thus extracted was washed with a saturated aqueous solution of sodium bicarbonate and dried over anhydrous magnesium sulfate, and then filtrated. The filtrate thus obtained was concentrated to dryness under reduced pressure to give 170 g (yield 62%) of 5,6-dimethoxy-1-indanone. However, in this method, a reaction vessel of approximately 3 L or larger is needed to obtain only 170 g of a target compound. Therefore, the volumetric efficiency is low. Also, industrialization of the above method is difficult because chloroform, which is highly toxic to human bodies and the environment, is used as an extraction solvent.

Provenance & Evidence