sodium in tetrahydrofuran; toluene Na suspended in boiling toluene, cooled, toluene removed, Na washed with THF, THF added, C2H2 introduced in suspn. with stirring, mixt. standing at 45°C for 1 h, cooled to room temp., soln. of Et2NBCl2 in THFadded for 1 h; filtered, solvents removed;

n-butyllithium in tetrahydrofuran; hexane C2H2 introduced in THF at -78°C for 1 h, soln. of Et2NBCl2 in THF added for 40 min, exclusion of O2 and moisture, after 1 h melted at -78°C, solvents evapd., residue warmed (170°C/E-3 Torr) condensate distd. (95°C/E-3 Torr); filtered, solvents removed; not sepd., detected by NMR;

in hexane excess of C2H2;