反应详情

To a slurry of 78 g of 4,5-methylenedioxy-2-nitrobenzaldehyde and 1.5 liter of water there was added a solution of 90 g of potassium permanganate in 1.5 liter of water over a period of 45 minutes. The mixture was then stirred at 70°-80° C. for an additional hour and then made alkaline with 400 ml of aqueous 10% potassium hydroxide. The mixture was filtered while hot to remove the precipitate which was washed with 2 portions of hot water. The filtrate was cooled for 16 hours and the solid which formed was separated by filtration to give recovered starting material. The new filtrate was acidified with concentrated hydrochloric acid and allowed to stand for 3 hours. The yellow solid which formed was separated by filtration to give crude product. The filtrate obtained was extracted with 4 portions of ethyl acetate and the combined extracts were dried over sodium sulfate and added to a solution of the previously obtained crude product in ethyl acetate. The ethyl acetate solution was concentrated, the resulting solid was slurried with chloroform, separated by filtration and dried to give 4,5-methylenedioxy-2-nitrobenzoic acid melting at about 160°-163° C.

1. filtrationThe mixture was filtered while hot
2. customto remove the precipitate which
3. washwas washed with 2 portions of hot water
4. temperatureThe filtrate was cooled for 16 hours
5. customthe solid which formed
6. customwas separated by filtration
7. customto give
8. customrecovered
9. customThe yellow solid which formed
10. customwas separated by filtration
11. customto give crude product
12. customThe filtrate obtained
13. extractionwas extracted with 4 portions of ethyl acetate
14. dry with materialthe combined extracts were dried over sodium sulfate
15. additionadded to a solution of the
16. custompreviously obtained crude product in ethyl acetate
17. concentrationThe ethyl acetate solution was concentrated
18. customseparated by filtration
19. customdried