反应详情

A solution of 4-[2-(3-Chloro-4-methoxycarbonyl-phenoxy)-acetyl]-piperazine-1-carboxylic acid tert-butyl ester from Example E41c.1 (4.5 g, 10.8 mmol) in THF at 0° C. was treated with potassium trimethylsilanolate (1.6 g, 10.9 mmol), and the mixture stirred at room temperature for 18 h. A further 1.6 g (10.9 mmol) potassium silanolate was added, and stirring continued at room temperature for 2 h. A further 1.6 g (10.9 mmol) potassium silanolate was added, and the mixture was stirred at 45° C. for 2 h. The mixture was then diluted with water and THF was removed in vacuo. The residue was washed with ether, cooled in an ice-bath and adjusted to pH5 with solid KHSO4 whereupon it was extracted with CHCl3 and CHCl3/isopropanol (90:10 v/v). The combined organics were dried and solvents were removed in vacuo to yield the title compound (3.7 g, 85%).

1. customat 0° C.
2. stirringstirring
3. waitcontinued at room temperature for 2 h
4. stirringthe mixture was stirred at 45° C. for 2 h
5. customwas removed in vacuo
6. washThe residue was washed with ether
7. temperaturecooled in an ice-bath
8. extractionwas extracted with CHCl3 and CHCl3/isopropanol (90:10 v/v)
9. customThe combined organics were dried
10. customsolvents were removed in vacuo