反应详情

温度

5 °C

To prepare compound 51.1, the procedure may be according to process “A”. 505 mg of amine 51.9 and 227.1 mg of triphosgene were dissolved in 15 ml of dry tetrahydrofuran. At 0° C., over 30 minutes, 0.864 ml of triethylamine in 2.5 ml of tetrahydrofuran was added dropwise and then the mixture was stirred at 5° C. for a further 10 minutes. 404.7 mg of the hydrochloride of tert-butyl 2-amino-2-methylpropionate were added, and the mixture was allowed to warm to room temperature and stirred at room temperature for a further 2 h. The reaction mixture was admixed with 2.5 ml of concentrated hydrochloric acid and stirred at room temperature for a further 2 h. For workup, the mixture was admixed with water and ethyl acetate, and the organic phase was removed, washed with saturated sodium chloride solution, dried over magnesium sulfate, filtered and concentrated under reduced pressure. The chromatographic purification was effected according to method [RP1]. The product-containing fractions were concentrated under reduced pressure, the residue was extracted by repeated shaking with dichloromethane, and the organic phase was dried over magnesium sulfate and concentrated under reduced pressure. 51.1 was obtained in 41% yield. 1H NMR: 8.85, s, 1H, 8.4, s, 1H, 8.3, d, 1H, 8.02, d, 1H, 1.4, s, 6H.

1. temperatureto warm to room temperature
2. stirringstirred at room temperature for a further 2 h
3. stirringstirred at room temperature for a further 2 h
4. customthe organic phase was removed
5. washwashed with saturated sodium chloride solution
6. dry with materialdried over magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customThe chromatographic purification
10. concentrationThe product-containing fractions were concentrated under reduced pressure
11. extractionthe residue was extracted
12. stirringby repeated shaking with dichloromethane
13. dry with materialthe organic phase was dried over magnesium sulfate
14. concentrationconcentrated under reduced pressure
15. custom51.1 was obtained in 41% yield