反应详情

To a 1-l. three-necked flask provided with a condenser, stirrer and dropping funnel was added 11 g. of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and 500 ml. of dioxane. To the solution heated to reflux, was added at a rapid rate a solution of 6 g. of 9-chloro-1,2,3,4-tetrahydrodibenzothiophene-3-acetic acid ethyl ester in 100 ml. of dioxane. The solution was refluxed and stirred for 24 hours, cooled to room temperature and then filtered to remove the hydroquinone. The solvent was removed in vacuo on the steam bath, and the residue was dissolved in 200 ml. of methylene chloride. This solution was passed through a column containing about 150 g. of alumina (Woelm, grade 1). The solvent was removed on the steam bath and the residue was crystallized from alcohol. The yield of 9-chlorodibenzothiophene-3-acetic acid ethyl ester was 1.1 g., m.p. 82°-84°.

1. customthree-necked flask provided with a condenser, stirrer
2. additionwas added 11 g
3. temperatureTo the solution heated
4. temperatureto reflux
5. additionwas added at a rapid rate a solution of 6 g
6. temperatureThe solution was refluxed
7. filtrationfiltered
8. customto remove the hydroquinone
9. customThe solvent was removed in vacuo on the steam bath
10. dissolutionthe residue was dissolved in 200 ml
11. additioncontaining about 150 g
12. customThe solvent was removed on the steam bath
13. customthe residue was crystallized from alcohol