反应详情

7 ml of a 10% w/v aqueous solution of sodium hydroxide and 10 ml of water were added to a solution of 3.2 g of ethyl 2-(1,2,3,4,10,14b-hexahydrodibenzo[c,f]pyrazino[1,2-a]azepin-2-yl)ethoxyacetate (prepared as described in Example 1) dissolved in 20 ml of ethanol. The mixture was then stirred at room temperature for 1 hour, after which it was concentrated to about one half of its original volume by distillation under reduced pressure. The pH of the concentrate was then adjusted to a value of 4.0 by the addition of 10% w/v aqueous hydrochloric acid, and the mixture was extracted with chloroform. Concentration of the extract by evaporation under reduced pressure yielded 2.96 g (a quantitative yield) of the title compound as a foamy substance, which was recrystallized from water to give colorless needles, melting at 135° C. (with decomposition).

1. concentrationafter which it was concentrated to about one half of its original volume by distillation under reduced pressure
2. additionThe pH of the concentrate was then adjusted to a value of 4.0 by the addition of 10%
3. extractionthe mixture was extracted with chloroform
4. extractionConcentration of the extract by evaporation under reduced pressure