反应详情

A solution of 0.6 g (1.84 mmol) of 4,4-dimethyl-8-propoxymethyl-1,1-dioxothiochromane-7-carboxylic acid, 0.18 g (1.84 mmol) of 1-methyl-5-hydroxypyrazole and 0.38 g (1.84 mmol) of N,N-dicyclohexylcarbodiimide in 20 ml of acetonitrile was stirred at room temperature for 12 hours. The reaction mixture was subsequently stirred into a mixture of ethyl acetate and 2% strength aqueous sodium carbonate solution, and the precipitate which formed was filtered off with suction. The organic phase of the filtrate was dried and the solvent was distilled off. The resulting residue was dissolved in 5 ml of 1,4-dioxane, 0.51 g (3.7 mmol) of potassium carbonate were added and the mixture was heated under reflux for 4 hours. After cooling, the reaction mixture was taken up in ethyl acetate/water, and the aqueous phase was adjusted to pH 3 using 2N hydrochloric acid and subsequently extracted with ethyl acetate. The extract was dried and the solvent was removed, giving a solid.

1. customthe precipitate which formed
2. filtrationwas filtered off with suction
3. customThe organic phase of the filtrate was dried
4. distillationthe solvent was distilled off
5. dissolutionThe resulting residue was dissolved in 5 ml of 1,4-dioxane
6. temperaturethe mixture was heated
7. temperatureunder reflux for 4 hours
8. temperatureAfter cooling
9. extractionsubsequently extracted with ethyl acetate
10. customThe extract was dried
11. customthe solvent was removed
12. customgiving a solid