in tetrahydrofuran N2 atmosphere; refluxing (24 h), pptn.; washing (dry Et2O);

in tetrahydrofuran byproducts: (C5H5)2ZrCl2; argon; exclusion of light; addn. of Me2GeCl2 in THF to soln. at -10°C; warming to 0°C; evapn. to dryness; extraction of residue (hexane); cooling to 6°C; elem. anal.;

in tetrahydrofuran byproducts: (C5H5)2ZrCl2; argon; exclusion of light; addn. of GeCl4 in THF to soln. at -10°C; warming to 0°C; evapn. of THF; addn. of toluene and filtration; evapn. to dryness; recrystd. (CH2Cl2) at -30°C; elem. anal.;

in not given hydrolysis in presence of (hygroscopic) LiCl;;

N,N'-dimethyl-N,N'-propyleneurea; copper(l) chloride in tetrahydrofuran T=-78 - 70°C; 1 h; Inert atmosphereSchlenk technique;

in tetrahydrofuran T=50°C; 12 h; Inert atmosphereSchlenk technique;