反应详情

3 g of 8-(4-Fluoro-phenyl)-1,4-dioxa-spiro[4.5]decane-8-carboxylic acid (75) and 3.3 mL of triethyl amine were dissolved in 50 mL of dry toluene. At 0° C. 2.83 mL of diphenyl phosphoryl azide was added dropwise. The mixture was stirred at room temperature until conversion was complete, then the solution was heated to 90° C. until gas evolution stopped. 3.4 mL of benzyl alcohol were added and stirring at 90° C. was continued for another 18 h. The mixture was allowed to cool down to room temperature and 500 mL of ethyl acetate were added. The organic layer was extracted two times with 1N HCl and once with brine, dried over magnesium sulfate and evaporated to dryness. The crude product was purified by silica gel chromatography to give 2.85 g of the desired product. Rt=2.52 min (Method E). Detected mass: 386.2 (M+1H+).

1. customAt 0° C
2. temperaturethe solution was heated to 90° C. until gas evolution
3. stirringstirring at 90° C.
4. temperatureto cool down to room temperature
5. extractionThe organic layer was extracted two times with 1N HCl
6. dry with materialonce with brine, dried over magnesium sulfate
7. customevaporated to dryness
8. customThe crude product was purified by silica gel chromatography