反应详情

1.0 g of 8-[2-(1,4-benzodioxan-2-yl)-2-hydroxyethyl]-1-oxa-3,8-diazaspiro[4.5]decan-2-one is dissolved in a solution of 5 ml of diethyl ether and 5 ml of ethanol at 20°. To this solution is added 10 ml of a saturated solution of maleic acid in ethyl ether. The mixture is allowed to stand for one hour at room temperature. The resulting precipitate is recovered by filtration, washed three times with diethyl ether and then crystallized from a mixture to diethyl ether and ethanol affording 8-[2-(1,4-benzodioxan-2-yl)-2-hydroxyethyl]-1-oxa-3,8-diazaspiro[4.5]decan-2-one maleate.

1. filtrationThe resulting precipitate is recovered by filtration
2. washwashed three times with diethyl ether
3. customcrystallized from a mixture to diethyl ether and ethanol