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PREPARATION OF CYCLOPROPANE DERIVATIVE
Using NaH and Pd(0)
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F SM/Reagent |
F Eq |
F Apparatus | |
CyanomethylImine (FW: 220.27) |
1.0 |
1 Neck flask | |
1,4-Dibromo-2-butene (FW: 213.91) |
1.0 |
Stirrrer | |
NaH (FW: 24, 60% in mineral oil) |
2.0 |
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Pd(Oac)2 (FW: 224.49) |
0.017 |
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PhP3 (FW: 262.29 |
0.033 |
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THF (Anhy) |
5ml/1mmol SM
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Procedure
1. Dissolve Imine and butene in THF. Stir (N2)
2. Add Pd(OAc)2 and Ph3P (as neat to form Pd(0)) [1]
3. Stir the mixture at R.T. for 30 min
4. Add slowly and portionally NaH (60% in mineral oil) over 45 min [2]
5. Stir the reaction mixture at R.T for 1 hr [3]
6. Quench reaction w/ ice cold water and dilute w/ EtOAc
7. Filter thru Celite [4]. Wash filtrate w/water and brine
8. Dry organic layer w/ MgSO4. Filter
9. Concentrate in vacuo ® crude as brownish oil
10. Chromatograph w/ 0% ® 5% EtOAc/Hex [5]
11. NMR w/ CDCl3. Yield 70% as yellow oil [6]
G Notes:
[1] Color change from light to darker yellowish solution
[2] Slow addition of NaH is very important. Gas , color change from yellow to green then brownish
[3] Follow reaction by TLC w/10% EtOAc/Hex
[4] Wash Celite pad w/EtOAc
[5] Dissolve the crude in Et2O
[6] 10% of Didebromination may obtain
Synlett 1996, November, p1067
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