4-Ferrocenylaniline

The reduction of 4-nitropheneylferrocene with tin in acidic condition gives 4-ferrocenylaniline, which is an important intermediate for the synthesis of ferrocene-containing Schiff’s base liquid crystals [1].

To a stirred mixture of 4-nitrophenylferrocene [2] (2 g, 7 mmol) in 25 ml of concentrated hydrochloric acid and 40 ml ethanol is added tin (granulated, 4.5 g, 40 mmol) and the reaction mixture is heated under reflux for 4 h. After the mixture has cooled, 200 ml water is added and aqueous NaOH is added to adjust the pH to 14 before filtration. The filtrate is extracted with CH2Cl2 and dried (Na₂SO₄). The solvent is removed by rotary evaporation. The crude product is recrystallized from petroleum ether (boiling range 60-80^oC) to give 4-ferrocenylaniline as an red-orange solid (1.4 g, 76%).

M.p: 157-159^oC.

IR(KBr, cm^-1): 3437, 3350, 1621, 1605, 1529, 1454, 1103, 998.

¹HNMR(CDCl3): 7.3(d, 2H, C₆H₄), 7.65(d, 2H, C₆H₄), 4.0(s, 5H, C₅H₅), 4.2(s, 2H, C₅H₄),

4.5(s, 2H, C₅H₄), 3.4(s, 2H, NH₂).

Elemental analysis for C₁₆H₁₅FeN: calculated, C, 68.57; H, 5.38; N, 5.00%. Found: C, 68.85; H, 5.46; N, 5.12%.