Grignard Synthesis of an Aromatic Acid

Overview

Grignard reagents, RMgX, were discovered roughly a hundred years ago, yet they are still regarded as one of the most useful carbon nucleophiles. A wide range of Grignard reagents can be prepared and these reagents react with a wide range of carbon electrophiles to make new carbon-carbon bonds.

In this experiment, you will attempt to generate a Grignard reagent from an unknown aryl bromide, ArBr, and then convert this reagent into an aromatic carboxylic acid, ArCO2H, by combining the Grignard reagent with solid CO2 (dry ice). You will identify your unknown aryl bromide by measuring physical and spectroscopic properties of the aromatic carboxylic acid.

synthetic plan