Catechol → 2-Chloro-3',4'-dihydroxyacetophenone

Participants

Reaction Conditions

Reaction Steps

Similar to the procedures of R. W. Schayer (J. Am. Chem. Soc. 74, 2441 [1952]) and N. Levin et al. (J. Org. Chem. 7, 408-415 [1942]), but without an additional solvent, a mixture of 100 g catechol, 750 g (450 ml) of phosphorus oxychloride and 206 g (145 ml) of chloracetyl chloride was stirred at reflux temperature (ca. 125° C.) in an argon atmosphere for 4.5 hours. Then most of the volatiles were distilled off at 80° C. (bath temperature) and, finally, under reduced pressure. To the nearly intractable dark mass were added at ca 80° C. 200 ml of water upon which the mixture became stirabel again. 600 ml of cold (0° C.) water were added in portions to control the exothermic reaction. When all of the water was added and the exothermic reaction had ceased the mixture was stirred for 2 hours under reflux. Upon stirring over night without further heating 125 g of crude product precipitated as dark brown crystals with a purity of about 90% (yield ca. 65%).

Provenance & Evidence