a key intermediate in the production of the antifungal agent metconazole also provided is the intermediate compound 5 5 cyano 2 2 dimethylcyclopentanone application_number US 87800001 A description previously described conditions for effecting the alkylation of isobutyronitrile with 1 bromo 3 chloropropane require the use of polar solvents and a reaction temperature of u2212 78 u00b0 c s s kulp v b fish and n r easton can j chem 1965 43 2512 m n romanelli f gaultiere r mannhold and a chiarini farmaco 1989 44 449 this temperature requirement is not readily attainable on a large manufacturing scale surprisingly it has now been found that the alkylation of isobutyronitrile in a non polar solvent in the presence of a base such as lithium bis trimethylsilylamide or lithium dimethylamide proceeds in high yield when conducted at temperatures up to 65 u00b0 c thus permitting a more efficient and effective manufacturing procedure advantageously the present invention provides an effective and practical method for the preparation of 5 4 chlorobenzyl 2 2 dimethycyclopentanone a key intermediate in the production of the antifungal agent metconazole in accordance with the process of the invention isobutyronitrile iii is alkylated with at least one molar equivalent of 1 bromo 3 chloropropane in a non polar solvent.