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

Participants

Reaction Steps

For example, Non-Patent Document 1 discloses that 1 g of 3-(3,4-dimethoxyphenyl)propionic acid and 10 g of polyphosphoric acid were reacted at 65° C. for 25 minutes, followed by addition of cold water. Then, the resulting mixture was extracted with diethyl ether or ethyl acetate, and the organic layer thus extracted was washed with a 10% aqueous solution of sodium bicarbonate and purified by crystallization with ethanol to give 0.812 g (yield 90%) of 5,6-dimethoxy-1-indanone. However, it is also reported that the yield dropped to 71% when the reaction time was extended to 70 minutes in the above method. Generally, each unit operation is time-consuming in an industrial-scale production, and thus, it is difficult to perform operations in such a way that reactions are completed within only several tens of minutes. In view of the foregoing, the method described in the above document is far from an industrially efficient production method.

Provenance & Evidence