反应详情

2-Ethyl-5-methoxy-6,7-dichloro-1-indanone (4 g.) is suspended in 200 ml. of water containing 1 ml. of 20% sodium hydroxide. The mixture is heated to boiling and potassium permanganate (18 g.) is added portion-wise over a four-hour period in such a manner that each time the purple color disappears an additional portion is added. A few drops of methanol are added to destroy the excess permanganate and the manganese oxide is removed by filtration. The colorless filtrate is acidified with 6 N HCl and evaporated to dryness under reduced pressure. The solid residue is extracted with boiling acetone and the extract is evaporated to dryness. The residue (2.57 g.) is suspended in 6 N HCl (125 ml.) and the mixture is boiled for 10 minutes, cooled and the 3,4-dichloro-5-methoxyphthalic acid is collected. On heating the product in a capillary melting point tube, it evolves a gas at 210° C. (formation of the anhdride), resolidifies and melts at 218°-220° C.

1. additionis added portion-wise over a four-hour period in such a manner that each time the purple color
2. additionis added
3. customto destroy the excess permanganate
4. customthe manganese oxide is removed by filtration
5. customevaporated to dryness under reduced pressure
6. extractionThe solid residue is extracted with boiling acetone
7. customthe extract is evaporated to dryness
8. temperaturecooled
9. customthe 3,4-dichloro-5-methoxyphthalic acid is collected
10. temperatureOn heating the product in a capillary
11. customat 210° C.