Toluene → 4-Benzoylbenzoyl chloride

Participants

Reaction Steps

4-Benzoylbenzoic acid (BBA), 1.0 kg (4.42 moles), was added to a dry 5 liter Morton flask equipped with reflux condenser and overhead stirrer, followed by the addition of 645 ml (8.84 moles) of thionyl chloride and 725 ml of toluene. Dimethylformamide, 3.5 ml, was then added and the mixture was heated at reflux for 4 hours. After cooling, the solvents were removed under reduced pressure and the residual thionyl chloride was removed by three evaporations using 3×500 ml of toluene. The product was recrystallized from 1:4 toluene:hexane to give 988 g (91 % yield) after drying in a vacuum oven. Product melting point was 92-94° C. Nuclear magnetic resonance (NMR) analysis at 80 MHz (1H NMR (CDCl3)) was consistent with the desired product: aromatic protons 7.20-8.25 (m, 9H). All chemical shift values are in ppm downfield from a tetramethylsilane internal standard. The final compound was stored for use in the preparation of a monomer used in the synthesis of photoactivatable polymers as described, for instance, in Example 3.

Provenance & Evidence