反应详情

Sodium hydride (2.2 g, 55 % dispersion in mineral oil) is added to a solution of isopropyl 4-fluorophenylacetate (3.9 g) in dry tetrahydrofuran (50 ml). The mixture is stirred for two hours at room temperature. 2-Methylthio-1,3-dithiolium perchlorate (5.5 g) is then added and the mixture is heated under reflux for seven hours. After cooling to room temperature, water (300 ml) is slowly added. The solution is extracted with ether (3×200 ml). The combined organic solutions are washed with water (100 ml), dried over magnesium sulphate and the solvents are evaporated in vacuo. The residue is purified by column chromatography on silica gel using hexane/toluene 1:9 as eluant. The product is recrystallized from ligroin and dried -in vacuo to constant weight to yield isopropyl (1,3-dithiol-2-ylidene)-(4-fluorophenyl)-acetate, m.p. 86° (as Example 8).

1. temperaturethe mixture is heated
2. temperatureunder reflux for seven hours
3. temperatureAfter cooling to room temperature
4. extractionThe solution is extracted with ether (3×200 ml)
5. washThe combined organic solutions are washed with water (100 ml)
6. dry with materialdried over magnesium sulphate
7. customthe solvents are evaporated in vacuo
8. customThe residue is purified by column chromatography on silica gel
9. customThe product is recrystallized from ligroin
10. customdried -in vacuo to constant weight