Reaktion #157676

Reaktionsgleichung

t-BuOK

acid 24

5,7-Dibromo-2-adamantane carboxylic acid

isocyanate

Et3N

diphenylphosphoryl azide

→

title compound

(5,7-Dibromo-adamantan-2-yl)-carbamic acid tert-butyl ester

Lösungsmittel

THF

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe resulting reaction mixture
2. 2
   Temperaturto warm to rt over 30 min
3. 3
   Sonstigeit was quenched with water
4. 4
   SonstigeThe THF was removed in vacuo
5. 5
   workup.ADDITIONthe resulting material was diluted with EtOAc
6. 6
   WaschenThe organic layer was washed with 1N HCl, sat. NaHCO3 and brine
7. 7
   Trocknendried (Na2SO4)
8. 8
   Filtrationfiltered
9. 9
   Einengenconcentrated in vacuo

Vorschrift

A suspension of the acid 24 (2.00 g, 5.92 mmol) in dry toluene (30 mL) was treated successively with Et3N (1.0 mL, 7.10 mmol) and diphenylphosphoryl azide (DPPA, 1.6 mL, 7.10 mmol). The resulting mixture was stirred at 85° C. for 15 h. To a separated flask containing a solution of t-BuOK (1.35 g, 11.8 mmol) in dry THF (80 mL) at 0° C. was added the isocyanate solution dropwise via a dropping funnel. The resulting reaction mixture was allowed to warm to rt over 30 min, and then it was quenched with water. The THF was removed in vacuo, and the resulting material was diluted with EtOAc. The organic layer was washed with 1N HCl, sat. NaHCO3 and brine, dried (Na2SO4), filtered and concentrated in vacuo. Flash chromatography (SiO2, 95:5 to 8:2, hexanes/EtOAc) afforded 1.20 g (50%, 2 steps) of the title compound as a white powder. 1H NMR (300 MHz, CDCl3) δ 4.68 (bs, 1H), 3.76 (bs, 1H), 2.87 (s, 2 H), 2.47-2.13 (m, 10H), 1.46 (s, 9H).

Quelle