Reaktion #674306

Reaktionsgleichung

Ether

Ethyl chloroformate

4-(benzyloxy)cyclohexanecarbonitrile

LDA

→

ethyl 4-(benzyloxy)-1-cyanocyclohexanecarboxylate

Ausbeute 33.6%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe solution was stirred at −78° C.
2. 2
   Temperaturto warm to room temperature slowly
3. 3
   workup.STIRRINGstirred overnight
4. 4
   SonstigeThe reaction was quenched by addition of H2O (20 mL), HCl (1.0 N, 20 mL)
5. 5
   ExtraktionIt was then extracted with EtOAc (3×40 mL)
6. 6
   WaschenThe combined organic solution was washed with brine (50 mL)
7. 7
   Trocknendried over anhydrous Na2SO4
8. 8
   Einengenconcentrated
9. 9
   Sonstigeto give pale yellow residue
10. 10
    workup.STIRRINGstirred for 5 min
11. 11
    Filtrationfiltered
12. 12
    Sonstigeto remove the white solid
13. 13
    EinengenThe ethereal solution was concentrated
14. 14
    Sonstigeto give the yellow oil which
15. 15
    Sonstigewas purified by CombiFlash (25 g silica gel column, EtOAc/Hexane: 0-20%)

Vorschrift

To a solution of 4-(benzyloxy)cyclohexanecarbonitrile (1.26 g, 5.85 mmol, 1.0 equiv) in THF (dry, 30 mL) was added a solution of LDA (3.95 mL, 2.0 M Heptane/THF/toluene, 1.35 equiv) dropwise at −78° C. under N2. The resulting yellow solution was stirred at −78° C. for 2 hrs. Ethyl chloroformate (2.79 mL, 29.26 mmol, 5.0 equiv) was then added by syringe dropwise. The solution was stirred at −78° C. and allowed to warm to room temperature slowly and stirred overnight. The reaction was quenched by addition of H2O (20 mL), HCl (1.0 N, 20 mL). It was then extracted with EtOAc (3×40 mL). The combined organic solution was washed with brine (50 mL), dried over anhydrous Na2SO4 and then concentrated to give pale yellow residue. Ether (40 mL) was added and stirred for 5 min, filtered to remove the white solid. The ethereal solution was concentrated to give the yellow oil which was purified by CombiFlash (25 g silica gel column, EtOAc/Hexane: 0-20%) to afford 565 mg (yield 33%) of ethyl 4-(benzyloxy)-1-cyanocyclohexanecarboxylate as a pale yellow oil.

Quelle