SYNTHESIS OF 2-PHENYLNITROETHANE

• Sodium hydride (0.72g, 0.03 mol) is dissolved in ethanol (30 ml). 

• Nitromethane (1.83g, 0.030 mol) is added with stirring, followed by 1 -benzyl- 2,4,6-triphenylpyridinium tetrafluoroborate(4.85g, 0.01 mol). 

• The solution is refluxed with stirring for 1 hour: the reaction is followed by t.l.c. (silica gel; chloroform). 

• When no further pyridinium compound remains, the solution is cooled; the resulting crystalline by-product 2,4,6-triphenylpyridine is filtered off. 

• The filtrate is added to water (50 ml), extracted with ether (3 x 25 ml) and the extract dried over magnesium sulphate. 

• Dry hydrogen chloride is passed into the ethereal extract to remove residual 2,4,6-triphenyl-pyridine, and the solution is evaporated under reduced pressure (25 °C/ 15mmHg). 

• The crude product is distilled in vacuo (15mmHg) to yield 2-phenylnitroethane, b.p. 120-130°C/15 mmHg, yield 78 per cent, pure by g.l.c. (Carbowax 220M, 200 °C); p.m.r. (CDCl₃ , TMS) 𝜹 3.45 (t,2H), 4.75 (t,2H), and 7.50 (s, 5H).