反应详情

To a microwave heating vial was add ethyl 4-(cyclopropyloxy)-2,6-difluorobenzoate (1 g, 4.13 mmol) and DBU (2.18 ml, 14.5 mmol). The reaction mixture was cooled with dry ice acetone bath. Methanethiol (˜1 ml) was condensed into the vial. The vial was sealed and the resulting reaction mixture was heated at 100° C. with microwave for 1 hour. The volatiles were removed by a stream of nitrogen. The residue was diluted with 60 ml ether, extracted with 2×30 ml 5% KOH. The aqueous portion was acidified with concentrated HCl to cause precipitation. The mixture was filtered and the precipitate was washed with 15 ml water. The resulting solid was air dried to give 0.37 g desired product as white solid. The organic portion was washed with 60 ml 1N HCl, dried over sodium sulfate, filtered and concentrated to give 0.78 g oil which contains mostly ethyl 4-(cyclopropyloxy)-2,6-bis(methylthio)benzoate. It was dissolved in 20 ml methanol and 3 ml water. LiOH (2 g) was added. The resulting reaction mixture was refluxed for 24 hours. The volatiles were removed, and the residue was dissolved in 40 ml water, washed with 30 ml ether, acidified with concentrated HCl to cause precipitation. It was filtered, washed with 20 ml water, air dried to give 0.52 g desired product as light yellow solid.

1. customThe resulting reaction mixture
2. temperaturewas refluxed for 24 hours
3. customThe volatiles were removed
4. dissolutionthe residue was dissolved in 40 ml water
5. washwashed with 30 ml ether
6. customprecipitation
7. filtrationIt was filtered
8. washwashed with 20 ml water, air
9. customdried