反応 #674306

反応方程式

Ether

Ethyl chloroformate

4-(benzyloxy)cyclohexanecarbonitrile

LDA

→

ethyl 4-(benzyloxy)-1-cyanocyclohexanecarboxylate

収率 33.6%

溶媒

THF

反応条件

後処理

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

実験手順

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.

出典