in benzene-d6 Ar atmosphere, 90°C (2 h); organic byproduct: 3-ethoxy-4-(fluoren-9-ylidene)-2-pentamethylene-5-phenyl-3,4-dihydro-2H-pyrrole; removement of solvent, chromy. (silica gel);

in pentane Ar atmosphere, addn. of soln. of amine, shaking, 20°C (2-3 d); organic byproduct: 3-ethoxy-4-(fluoren-9-ylidene)-2-pentamethylene-5-phenyl-3,4-dihydro-2H-pyrrole; decantation, washing of solid (toluene), evapn. (20°C, 10 Torr), chromy. (W byproducts, silica gel, C5H12/CH2Cl2 (2:1)), sepn. of W(CO)6 (dissoln. of solid (CH2Cl2), crystn. (-15°C)), crystn. of tungstate (20°C, C5H12); elem. anal.;