Реакция #441285

Уравнение реакции

2-hydroxyacetophenone

diethyl oxalate

sodium ethylate

sulfuric acid

→

ethyl 4-oxochromene-2-carboxylate

Выход 189.8%

Растворители

water

toluene

ethanol

Условия реакции

Обработка

1. 1
   workup.ADDITIONwas subsequently added
2. 2
   Другоеthe mixture was subjected to separation of the organic layer
3. 3
   КонцентрированиеThe resultant organic layer was concentrated
4. 4
   workup.ADDITIONafter which 55.0 g of hexane was added
5. 5
   Фильтрацияthe mixture was filtered below 10° C. which

Методика

In a mixture containing 180 g of toluene and 12.0 g of diethyl oxalate was dissolved 30 g of 2-hydroxyacetophenone, to which 65.0 g of a 20% solution of sodium ethylate in ethanol was added dropwise. After completion of the reaction 13 g of 98% sulfuric acid was subsequently added, and the mixture was stirred at 60° C. for about 30 minutes. Then 140 g of water was added, and the mixture was subjected to separation of the organic layer. The resultant organic layer was concentrated, after which 55.0 g of hexane was added and the mixture was filtered below 10° C. which yields about 34.0 g of ethyl 4-oxochromene-2-carboxylate. (Approximately 95% yield).

Источник