Abstract The direct displacement of an o-methoxy group in o-methoxyaryl ketones with aryl, alkyl, and alkenyl Grignardreagents to provide a series of o-substituted ketones is described. Application of this reaction to the synthesis of a C-methyl analogue of a cyclooxygenase inhibitor is shown. The scope and limitations are discussed. The direct displacement of an o-methoxy group in o-methoxyaryl ketones