反应详情

A solution of KMnO4 (24.81 g, 0.157 mole) in water (100 ml) was added under stirring with a solution of tetrabutylammonium bromide (50.61 g, 0.157 mole) in water (200 ml), diluting with further water (200 ml). The solid was separated by filtration, squeezed and dissolved in pyridine (300 ml). The solution was dropped into a solution of 3-benzyloxy-4-methoxy-benzaldehyde (38.2 g, 0.157 mole), prepared as described in example 52, in pyridine (150 ml) in water bath. After 3 hours the mixture was brought to acidic pH with 1N HCl, the solid was filtered off and the mother liquors were extracted more times with CH2Cl2. The organic phase was anhydrified, concentrated and the residue taken up in 1N NaOH and washed with ethyl ether. The aqueous solution was acidified and extracted twice with CH2Cl2, brought to dryness, discoloured with TONSIL® and concentrated to small volume. The precipitate was filtered to give 35.869 g of the title compound (yield: 88%).

1. customThe solid was separated by filtration
2. dissolutiondissolved in pyridine (300 ml)
3. customprepared
4. filtrationthe solid was filtered off
5. extractionthe mother liquors were extracted more times with CH2Cl2
6. concentrationconcentrated
7. washwashed with ethyl ether
8. extractionextracted twice with CH2Cl2
9. concentrationconcentrated to small volume
10. filtrationThe precipitate was filtered