copper(l) iodide in further solvent(s) stirring of a mixt. of phenylacetylene, 4-iodo-3H-phenothiazinone, PdCl2(PPh3)2 and CuI in N-methylpiperidine (room temp., 12 h), removal of solvent, triturating of the residue with ether; washing of the ether layer with HCl (pH 4), drying (Na2SO4), evapn. of solvent, chromy. (silica gel, hexane); traces of the Pd complex from the ether-insol. fraction by column chromy.;