| abstract |
A process for the preparation of 2,2-dimethyl-5-(4-chlorobenzyl)cyclopentanone (I) by reaction isobutyronitrile with 1-bromo-3-chloropropane in the presence of a first base in a non-polar solvent to afford 5-chloro-2,2-dimethylpentanenitrile; 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; 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; hydrolyzing said 3,3-dimethyl-2-amino-1-cyanocyclopentene in the presence of an acid to give 5-cyano-2,2-dimethylcyclopentanone; 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-chorobenzyl)-5-cyano-2,2-dimethylcyclopentanone; and 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; the compound, 5-(4-chlorobenzyl)-5-cyano-2,2-dimethylcyclopentanone. |