copper in N,N-dimethyl-formamide T=130°C; 20 h; Inert atmosphere;

copper in N,N-dimethyl-formamide T=130°C; 72 h; Inert atmosphere;

sodium dithionite; sodium hydrogencarbonate in dimethyl sulfoxide T=75°C; 8 h; Title compound not separated from byproducts;

copper bronze 1) DMSO, 125 deg C, 1.5 h; 2.) 125 deg C, 19 h; Yield given. Multistep reaction. Further byproducts given. Yields of byproduct given. Title compound not separated from byproducts;