Thirteen hundred milliliters of 1,2-dimethoxyethane (glyme) is distilled from
lithium aluminum hydride (Caution! Under no circumstances should distillation be carried to dryness since explosive decomposition of the residual hydride may occur.) (Note
2) directly into a
2-l., nitrogen-flushed, three-necked, Morton flask equipped with a
nitrogen inlet, an outlet, and a high-speed stirrer with a stainless steel propeller-type blade. The flask is charged with
89.7 g. (0.87 mole) of t-nitrobutane (Note
3) and
19.9 g. (0.87 g. atom) of sodium cut into pea-sized pieces (Note
4). The stirrer is started and initially operated at a speed just adequate to draw some of the
sodium through the blade. The onset of reaction is signaled when the solution is pale lavender and the
sodium surface is clearly etched and colored bright gold (Note
5). The temperature of the reaction mixture is maintained at 25–30° (Note
6) by directing an air blast at the sides of the flask and by controlling the rate at which
sodium is drawn through the blades of the stirrer. As the reaction progresses, colorless solid is formed, and at the end of the reaction (
ca. 24 hours) the reaction mixture consists of solid and a colorless
glyme solution. Most of the
glyme is removed by evaporation under reduced pressure at room temperature with a
water bath at 20–25° to leave a thick, colorless slurry. To the slurry under
nitrogen (Note
7) is added 270 ml. of water, and the reddish brown organic layer is separated. The aqueous layer (Note
8) is extracted with several portions of
pentane until the extract is colorless. The organic layer and
pentane extracts are combined, cooled to 0°, and washed rapidly and thoroughly with two
70-ml. portions of ice-cold 0.25N hydrochloric acid to remove hydroxylamine impurities (Note
9). The
pentane solution of the product is washed immediately with 70 ml. of cold water followed by
70 ml. of cold, aqueous 0.2N sodium hydroxide. The combined, cold, aqueous acidic washings are extracted with small portions of
pentane until colorless. This
pentane extract is used to extract the aqueous
sodium hydroxide layer and is then washed with water and combined with the initial
pentane extract.