반응 #450470

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ethylvanillin

isobutyric anhydride

→

ethylvanillin isobutyrate

수율 71.6%

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후처리

1. 1
   기타fitted with a 30 cm
2. 2
   workup.ADDITIONWhen addition
3. 3
   workup.DISTILLATIONthe isobutyric acid can firstly be distilled off at a still temperature of 120° C. and 150 mbar, and iso-butyric acid and excess anhydride
4. 4
   workup.DISTILLATIONcan finally be distilled at up to 130° C.
5. 5
   workup.ADDITION500 ml of isopropanol are added
6. 6
   기타crystallization
7. 7
   온도cooling to 7° C
8. 8
   여과The crystals are filtered off with suction
9. 9
   세척washed twice with 60 ml of cold isopropanol
10. 10
    기타dried

실험 절차

166 g of ethylvanillin are introduced into a 500 ml three-neck flask fitted with a 30 cm packed column and melted, and 189.6 g of isobutyric anhydride are added at a maximum temperature of 100° C. The reaction is only slightly exothermic. When addition is complete, the isobutyric acid can firstly be distilled off at a still temperature of 120° C. and 150 mbar, and iso-butyric acid and excess anhydride can finally be distilled at up to 130° C. and 20 mbar. The system is allowed to cool to 90° C., 500 ml of isopropanol are added and crystallization takes place upon further stirring and cooling to 7° C. The crystals are filtered off with suction, washed twice with 60 ml of cold isopropanol and dried, giving 182 g of ethylvanillin isobutyrate. Repeated crystallization from the mother liquor produces another 22.8 g of ethylvanillin isobutyrate.

출처