反应详情

A mixture of 1-(6,7-dihydroxy-1,2-dihydro-3-naphthoyl)-4-(3,4,5-trimethoxybenzyl)piperazine hydrobromide (0.3 g), ethyl acetate (20 ml), triethylamine (0.5 ml) and acetic anhydride (0.5 ml) is left standing at room temperature overnight. Ethanol (5 ml) is added to the mixture. The whole mixture is left standing for one hour and then concentrated under reduced pressure. The residue is purified by silica gel column chromatography (hexane:acetone=1:1-1:2) to give an oily product. This product is dissolved in ethyl ether. An ethyl ether solution (50 ml) of fumaric acid (0.1 g) is added to the solution. The mixture is diluted with petroleum ether, whereupon colorless powder precipitates out. The precipitates are collected by filtration to give 1-(6,7-diacetyloxy-1,2-dihydro-3-naphthoyl)-4-(3,4,5-trimethoxybenzyl)piperazine fumarate (0.25 g) as colorless powder.

1. waitis left
2. waitThe whole mixture is left
3. waitstanding for one hour
4. concentrationconcentrated under reduced pressure
5. customThe residue is purified by silica gel column chromatography (hexane:acetone=1:1-1:2)
6. customto give an oily product
7. customprecipitates out
8. filtrationThe precipitates are collected by filtration