Method of preparing 2-aryl-1,3-cyclohexanedione compounds

A method of preparing a compound of the formula:

• ##STR8## which comprises treating a compound of the formula:
• ##STR9## with acid, wherein:
• Z, Z', Z"' and Z''' are individually hydrogen, nitro, polyhaloalkyl, halogen, cyano, alkyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkanoyl, amido, amino or haloalkyl;
• R.sub.1 is alkyl, halogen, polyhaloalkyl, or haloalkyl;
• R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 are individually hydrogen or either substituted or unsubstituted alkyl or phenyl wherein the permissible substituents are one or more alkyl, cyano, halogen, nitro, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, or dialkylamino substituents or any two R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 or R.sub.7 substituents together may form an alkylene or alkenylene chain having from 2 to 20 carbon atoms completing a 3, 4, 5, 6 or 7 membered ring structure;
• with the proviso that R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, Z, Z', Z" and Z''' substituents individually may not include more than ten aliphatic carbon atoms.