Reaktion #436576

Reaktionsgleichung

1-methylimidazole

4-chlorophenyl-4-nitrophenyl-methanone

Chlorotrietylsilane

→

(±)-α-(4-chlorophenyl)-1-methyl-α-(4-nitrophenyl)-1H-imidazole-2-methanol

Ausbeute 20.0%

(±)-α-(4-chlorophenyl)-1-methyl-α-(4-nitrophenyl)-1H-imidazole-5-methanol

Ausbeute 26.6%

Lösungsmittel

THF

hexane

THF

hexane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigewas brought slowly to 10° C.
2. 2
   workup.ADDITIONwas added dropwise
3. 3
   workup.STIRRINGThe mixture was stirred at −70° C. for 1 hour
4. 4
   Sonstigebrought to −15° C.
5. 5
   Temperaturcooled again to −70° C
6. 6
   workup.ADDITIONwas added dropwise
7. 7
   workup.STIRRINGThe mixture was stirred at −70° C. for 30 minutes
8. 8
   Extraktionhydrolized and extracted with EtOAc
9. 9
   SonstigeThe organic layer was separated
10. 10
    Sonstigedried
11. 11
    Filtrationfiltered
12. 12
    Sonstigethe solvent was evaporated
13. 13
    SonstigeThe residue was purified by column chromatography over silica gel (eluent: CH2Cl2/CH3OH/NH4OH 96/4/0.1)
14. 14
    SonstigeThe desired fractions were collected
15. 15
    Sonstigetheir solvents were evaporated

Vorschrift

n-Buthyl-lithium in hexane (1.6M; 71.6 ml) was added dropwise at −70° C. under N2 flow to a mixture of 1-methylimidazole (0.1146 mol) in THF (195 ml). The mixture was stirred at −70° C. for 30 minutes. Chlorotrietylsilane (0.1146 mol) was added. The mixture was brought slowly to 10° C. and cooled again to −70° C. n-Buthyl-lithium in hexane (1.6M; 71.6 ml) was added dropwise. The mixture was stirred at −70° C. for 1 hour, brought to −15° C. and cooled again to −70° C. A mixture of 4-chlorophenyl-4-nitrophenyl-methanone (0.095 mol) in THF (150 ml) was added dropwise. The mixture was stirred at −70° C. for 30 minutes, hydrolized and extracted with EtOAc. The organic layer was separated, dried, filtered and the solvent was evaporated. The residue was purified by column chromatography over silica gel (eluent: CH2Cl2/CH3OH/NH4OH 96/4/0.1). The desired fractions were collected and their solvents were evaporated, yielding 6.5 g (20%) of (±)-α-(4-chlorophenyl)-1-methyl-α-(4-nitrophenyl)-1H-imidazole-2-methanol (interm 12), 8.7 g (26.6%) of (±)-α-(4-chlorophenyl)-1-methyl-α-(4-nitrophenyl)-1H-imidazole-5-methanol (interm 13) and 18 g (53%) of the mixture of intermediate 12 and 13.

Quelle