Phosgene → Benzoyl chloride, 3,4,5-trimethoxy-

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Reaction Steps

A mixture of 100 g of 3,4,5-trimethoxybenzoic acid, 150 g of xylene and 0.1 g of dimethyl-dodecyl-phosphine oxide is treated with phosgene at 100°C in the apparatus described for example 1. After a lapse of abt. 1 hour and phosgene consumption of 140 g the absorption of phosgene is terminated. At the end of a two-hours-postreaction a yellow solution of 3,4,5-trimethoxy-benzoylchloride is obtained. The yield in dissolved acid chloride is approx. 106 g, corresponding to 97.5% of the theoretical yield, calculated on the acid used. The solution may be used directly for further reactions after having eliminated the remaining phosgene by means of nitrogen or by distillation of a part of the solvent. But it is also possible to isolate the trimethoxy-benzoylchloride in its pure form by means of vacuum distillation (boiling point: 137°C/1.5 torr. softening point: 80 to 81°C).

Provenance & Evidence