反应详情

152 g of sodium hydrosulfite were added, whilst ice-cooling, to a mixture of 36.15 g of 2,3,6-trimethyl-benzoquinone-4-oxime [prepared as described in step (b) above] and 880 ml of a 1N aqueous solution of sodium hydroxide, and the resulting mixture was stirred at room temperature for 1 hour, after which it was allowed to stand overnight. The reaction mixture was then poured into ice-water and the pH of the aqueous mixture was adjusted to a value of 4 to 5 by the addition of 5N aqueous hydrochloric acid, after which it was neutralized with sodium hydrogencarbonate. The mixture thus obtained was extracted with ethyl acetate. The extract was washed with a saturated aqueous solution of sodium chloride and dried over anhydrous sodium sulfate. The solvent was then removed by distillation under reduced pressure, after which the crystalline residue was triturated with diisopropyl ether and collected by filtration. On washing with diisopropyl ether, there were obtained 30.1 g of the title compound, melting at 131°-134° C.

1. waitto stand overnight
2. customThe mixture thus obtained
3. extractionwas extracted with ethyl acetate
4. washThe extract was washed with a saturated aqueous solution of sodium chloride
5. dry with materialdried over anhydrous sodium sulfate
6. customThe solvent was then removed by distillation under reduced pressure
7. customafter which the crystalline residue was triturated with diisopropyl ether
8. filtrationcollected by filtration
9. washOn washing with diisopropyl ether