Na2B4O7; Oxonereg;; C6H12O6(C3H4)2; (ethylenedinitrilo)tetraacetic acid disodium salt; potassium carbonate in water; acetonitrile T=0°C; 1.5 h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

sodium hydride in tetrahydrofuran

in acetonitrile Ambient temperature;