KH in N,N-dimethyl acetamide (vac. or Ar); treatment of soln. of urea deriv. in dimethylacetamide with KH, addn. of nickel compd., stirring for 45 min, addn. of potassium tert-butoxide, addn. of tetramethylammonium salt, stirring for 1 h; evapn. triturating with diethyl ether, isolation of ppt., elem. anal.;

in N,N-dimethyl acetamide (Ar); treatment of soln. of urea deriv. in dimethylacetamide with 2 equiv. of KH at room temp., addn. of 1 equiv. of nickel compd. at room temp., filtration, addn. of 1 equiv. of KH, addn. of 1 equiv. of water; evapn., triturating with ether, isolation of ppt., IR and UV;