in diethyl ether room temp.; 8 h; reaction monitored by (1)H NMR spectroscopy;

in diethyl ether stirring (N2 atmosphere, 48 h), evapn. (reduced pressure, then 50 °C/0.001 torr); washing (pentane), drying (vac.), recrystn. (Et2O/pentane, -40°C); elem. anal.;

in benzene 25.degree C;

in diethyl ether room temp.; 8 h; reaction monitored by (1)H NMR spectroscopy;