Reaktion #71268

Reaktionsgleichung

(R)-5-bromo-2,3-dihydro-1H-inden-2-amine((1S,4R)-7,7-dimethyl-2-oxobicyclo[2.2.1]heptan-1-yl)methanesulfonate

potassium carbonate

benzyl chloroformate

→

(R)-benzyl 5-bromo-2,3-dihydro-1H-inden-2-ylcarbamate

Ausbeute 89.5%

Lösungsmittel

water

ethylacetate

EtOAc

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONadded
2. 2
   TemperaturThe mixture was cooled in an ice bath
3. 3
   Sonstigecame to room temperature
4. 4
   SonstigeThe crude reaction mixture
5. 5
   workup.ADDITIONthe phases mixed
6. 6
   Sonstigeseparated
7. 7
   ExtraktionThe aqueous layer was further extracted with EtOAc (×2)
8. 8
   SonstigeCombined organics were dried
9. 9
   Einengenconcentrated before crystallisation of the product from ethylacetate/heptane mixture

Vorschrift

(R)-5-bromo-2,3-dihydro-1H-inden-2-amine((1S,4R)-7,7-dimethyl-2-oxobicyclo[2.2.1]heptan-1-yl)methanesulfonate (12.56 mmol, 5.58 g) was dissolved in EtOAc (30 mL)/water (30 mL) and potassium carbonate (37.7 mmol, 5.21 g) added. The mixture was cooled in an ice bath and benzyl chloroformate (13.81 mmol, 1.964 mL, 2.356 g) added dropwise. Stirring was continued overnight during which time the reaction came to room temperature. The crude reaction mixture was diluted with water and ethylacetate and the phases mixed and separated. The aqueous layer was further extracted with EtOAc (×2). Combined organics were dried and concentrated before crystallisation of the product from ethylacetate/heptane mixture to give (R)-benzyl 5-bromo-2,3-dihydro-1H-inden-2-ylcarbamate as colourless needles (3.89 g, 89%). 1H NMR (400 MHz, CDCl3) δ 2.79 (m, 2H) 3.26 (m, 2H) 4.53 (bm, 1H) 4.93 (bm, 1H) 5.10 (bs, 2H) 7.07 (m, 1H) 7.26-7.37 (m, 7H)

Quelle