Thionyl Chloride → 2,3,4,5-Tetramethylbenzoyl chloride

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Reaction Steps

A 3 L 3-necked flask is equipped with a condenser, argon inlet, thermowell, magnetic stirrer. The flask is purged with argon then charged with 2,3,4,5-tetramethylbenzoic acid (138.3 g, 0.776 mol), methylene chloride (1.5 L), thionyl chloride (73.5 mL, 1.01 mol) and N, N-dimethylformamide (2.0 mL, 0.026 mol). The resulting suspension is heated to reflux, after a clear solution is formed, heating is continued for 3.5 hours. The solution is allowed to cool then concentrated in vacuo. Last traces of thionyl chloride are removed by co-distillation with toluene (2×100 mL). The remaining oil is dried under high vacuum then used without further purification. Additional reactions are carded out to produce a total of 218 g of 2,3,4,5-tetramethylbenzoyl chloride.

Provenance & Evidence