反应详情

3-Dipropylamino-5-methyloxycarbonylchroman (Example 2; 1.0 g, 3.4 mmol) was dissolved in methanol (20 ml). Sodium hydroxide (0.16 g, 4.1 mmol) in water (1.0 ml) was added and the solution was refluxed with nitrogen overnight. The solution was evaporated to dryness, toluene (20 ml) was added and again the solution was evaporated to dryness. The residue was dissolved in toluene 20 ml, diphenylphosphoryl azid (1.87 g, 6.8 mmol) was added and the solution was refluxed for 2 hours. Methanol (2.0 ml) was added and reflux was continued for 4 hours. The solution was cooled, washed with water and extracted with dilute HCl (aq.). The acidic water phase was neutralized NaOH (aq.) and extracted with toluene. The toluene-phase was dried with sodium sulphate and evaporated to dryness. The residue was dissolved in ethanol containing 10% NaOH (20 ml) and the solution was refluxed overnight. The solution was cooled and diluted with toluene. Washing with water, drying of the organic phase and evaporation to dryness afforded the title compound as an oil, which was converted to a dihydrochloride salt. Mp 173°-174° C.

1. temperaturethe solution was refluxed with nitrogen overnight
2. customThe solution was evaporated to dryness, toluene (20 ml)
3. additionwas added
4. customagain the solution was evaporated to dryness
5. dissolutionThe residue was dissolved in toluene 20 ml
6. temperaturethe solution was refluxed for 2 hours
7. temperaturereflux
8. temperatureThe solution was cooled
9. washwashed with water
10. extractionextracted with dilute HCl (aq.)
11. extractionextracted with toluene
12. dry with materialThe toluene-phase was dried with sodium sulphate
13. customevaporated to dryness
14. dissolutionThe residue was dissolved in ethanol containing 10% NaOH (20 ml)
15. temperaturethe solution was refluxed overnight
16. temperatureThe solution was cooled
17. additiondiluted with toluene
18. washWashing with water
19. customdrying of the organic phase and evaporation to dryness