sodium tetrafluoroborate; magnesium in diethyl ether T=8°C; Grignard reaction;

sodium chloride in methanol after removal of CH3OH dissolving in ether and passed through an ion exchange column of basic alumina; the ether eluate is treated with alkaline water, ether evapd.; aq. medium is satd. with NaCl and extrd. with ether; evapd. the ether and drying of the residue under vac. over P4O10 at 80°C; pure salt;

in diethyl ether at about 25°C;