Preparation of Metallic Nickel Powders and Their Reaction with 4-Nitrobenzyl Chloride

Preparation of Metallic Nickel Powders and Their Reaction with 4-Nitrobenzyl Chloride 

To the nickel powders 4r nitrobenzyl chloride (1.97 g, 11.5 mmol) in glyme (10 ml) was added and stirred at room temperature for Ih. The reddish-brown colored reaction mixture formed was poured into 3% hydrochloric acid solution (100 ml) and was extracted with chloroform twice (150 ml). The extracts were washed with water (50 ml), and the aqueous phase was extracted with chloroform. The chloroform solution was dried over anhydrous sodium sulftite. After evaporation of the solvent, the residue was washed with pentane twice (15 ml) to give pale yellow needles (mp 176-179 C). Recrystallization from ethanol gave l,2-bis(4-nitrophe-nyl)ethane (1.22g, 78%) mp 182-183 C (lit. [78] mp 183-184 C). 

The reaction of 4-nitrobenzyl chloride (3.37 g, 19.6 mmol) with nickel prepared from nickel iodide (3.86 g, 12.4 mmol) proceeded smoothly at room temperature for 2h and gave l,2-bis(4-nitrophenyl)ethane in 76% yield. 

All other coupling reactions were carried out using the reagents in the ratio of metallic nickel/one halogen for coupling = 1/0.8 to optimize the yield and to shorten the reaction time. 

5 Rieke, R.D. Chao, L. Synth. React. Inorg. Met.-Org. Chem. 1974, 4,101. 

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