Claims
- 1. The compound, 5-(4-chlorophenyl)-5-cyano-2,2-dimethylcyclopentanone.
- 2. A process for the preparation of 5-(4-chlorobenzyl)-2,2-dimethylcyclopentanone which comprises the following steps:
(a) reacting isobutyronitrile with 1-bromo-3-chloropropane in the presence of a first base in a non-polar solvent at a temperature of about 15° to 65° C. to afford 5-chloro-2,2-dimethylpentanenitrile; (b) treating said 5-chloro-2,2-dimethylpentanenitrile with a cyanide-delivering reagent in the presence of a phase-transfer catalyst to form 2,2-dimethyladiponitrile; c) cyclizing said 2,2-dimethyladiponitrile in the presence of a second base in a non-polar solvent to afford 3,3-dimethyl-2-amino-1-cyanocyclopentene; (d) hydrolyzing said 3,3-dimethyl-2-amino-1-cyanocyclopentene with acid to give 5-cyano-2,2-dimethylcyclopentanone; (e) treating said 5-cyano-2,2-dimethylcyclopentanone with 4-chlorobenzyl chloride in the presence of a third base in a polar aprotic solvent to form 5-(4-chlorobenzyl)-5-cyano-2,2-dimethylcyclopentanone; and (f) hydrolyzing said 5-(4-chlorobenzyl)-5-cyano-2,2-dimethylcyclopentanone in the presence of an acid to give the desired 5-(4-chlorobenzyl)-2,2-dimethylcyclopentanone compound.
- 3. The process according to claim 2 wherein said first base is lithium bis(trimethylsilyl)amide or lithium amide.
- 4. The process according to claim 2 wherein said non-polar solvent is hexane, heptane, toluene or ethylbenzene.
- 5. The process according to claim 2 wherein said second base is sodium t-butoxide.
- 6. The process according to claim 2 wherein said cyanide-delivering reagent is sodium cyanide.
- 7. The process according to claim 2 wherein said phase-transfer catalyst is tetrabutylammonium hydrogen sulfate.
- 8. The process according to claim 2 wherein said third base is sodium hydride.
- 9. The process according to claim 2 wherein said polar aprotic solvent is N,N-dimethylformamide.
- 10. The process according to claim 2 wherein said acid is sulfuric acid.
- 11. The process according to claim 4 wherein the first base is lithium bis(trimethylsilyl)amide or lithium amide and the cyanide-delivering agent is sodium cyanide.
- 12. The process according to claim 11 wherein the second base is sodium t-butoxide and the polar aprotic solvent is N,N-dimethylformamide.
- 13. The process according to claim 12 wherein the third base is sodium hydride.
- 14. The process according to claim 13 wherein the acid is sulfuric acid.
Parent Case Info
[0001] This application claims the benefit under 35 U.S.C. 119 (e) of provisional application 60/210,768 filed Jun. 12, 2000.
Provisional Applications (1)
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Number |
Date |
Country |
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60210768 |
Jun 2000 |
US |