M. Nencki, N. Sieber, J. Prakt. Chem. (2) 23, 147 (1881).
The ring acylation of phenols with acids in the presence of zinc chloride, or the modification of the Friedel-Crafts reaction, q.v., by substitution of ferric chloride for aluminum chloride.
M. Nencki, W. Schmid, ibid. 546; M. Nencki, ibid. 25, 273 (1882); U. S. Chiema, K. Venkataraman, J. Chem. Soc. 1932, 918; C. W. Schellhammer, Houben-Weyl 7/2a, 284 (1973); A. S. Anjaneyulu et al., Indian J. Chem. 33B, 847 (1994). Cf. Darzens-Nenitzescu Synthesis of Ketones.