Reaktion #219163

Reaktionsgleichung

phenyl-carbamic acid tert-butyl ester

t-BuLi

pentan

cyclopentanecarboxylic acid methoxy-methyl-amide

→

(2-amino-phenyl)-cyclopentyl-methanone

Ausbeute 87.8%

Lösungsmittel

Et2O

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto warm to room temperature
2. 2
   workup.STIRRINGstirred for further 1 h before it
3. 3
   Sonstigewas quenched with aqueous NH4Cl
4. 4
   SonstigeThe organic phase was isolated
5. 5
   Extraktionthe aqueous phase was extracted with CH2Cl2
6. 6
   Sonstigethe combined organic phases were dried
7. 7
   Einengenconcentrated in vacuo
8. 8
   workup.DISSOLUTIONThe crude material was dissolved CH2Cl2 (18 mL) and TFA (6 mL)
9. 9
   workup.STIRRINGstirred at room temperature for 2 h
10. 10
    SonstigeThe reaction mixture was evaporated in vacuo
11. 11
    workup.ADDITIONadded aqueous NaHCO3 to pH 7
12. 12
    Extraktionextracted with CH2Cl2
13. 13
    SonstigeThe combined organic phases were dried
14. 14
    Einengenconcentrated in vacuo

Vorschrift

To a stirred solution of phenyl-carbamic acid tert-butyl ester (1.2 g, 6.2 mmol) in Et2O (12 mL) under a nitrogen atmosphere was added dropwise a 1.7 M solution of t-BuLi in pentan (8.4 mL, 14.3 mmol) over a 10-min period at −20° C. The mixture was stirred at −10° C. for 2.5 h and then cyclopentanecarboxylic acid methoxy-methyl-amide (1.07 g, 6.8 mmol) was added over 5 min. The mixture was allowed to warm to room temperature and stirred for further 1 h before it was quenched with aqueous NH4Cl. The organic phase was isolated and the aqueous phase was extracted with CH2Cl2, and the combined organic phases were dried and concentrated in vacuo. The crude material was dissolved CH2Cl2 (18 mL) and TFA (6 mL) and stirred at room temperature for 2 h. The reaction mixture was evaporated in vacuo, and added aqueous NaHCO3 to pH 7 and extracted with CH2Cl2. The combined organic phases were dried and concentrated in vacuo to give 1.03 g (68%) of (2-amino-phenyl)-cyclopentyl-methanone as an oil.

Quelle