Sulfuric Acid → Ethyl 4-oxo-4H-1-benzopyran-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

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).

Provenance & Evidence