1,1'-FERROCENEDICARBOXALDEHYDE

Dark red solid

The literature procedure [26b] for the preparation of 9 was modified as follows: To a room temperature solution of ferrocene (10 g, 0.054 mol) in dry hexane (200 mL) was added n-butyl lithium solution (67 mL, 1.6 M in hexanes, 0.10 mol) dropwise followed by addition of tetramethylene ethylenediamine (TMEDA) (14.7 g, 0.25 mol). To a solution of ferrocene (6 g, 32 mmol) in hexane (100 mL) was addedtetramethylethylenediamine (TMEDA) (10.6 mL, 71 mmol) and n-butyllithium (46.4 mL, 74 mmol) and the mixture stirred overnight at room temperature. The reaction was cooledto -78° C and a solution of DMF (5.5 mL, 71 mmol) in Et2O (100 mL) was added. Themixture was allowed to warm to room temperature and stirred for 4 h. The reaction wasquenched with brine (100 mL) and extracted with CH2Cl2( 100 mL). The organic phasewas dried over MgSO4 and the solvent removed in vacuo. The product was purified bycolumn chromatography on silica gel using hexane/ether followed by hexane/ether/ethylacetate. Yield 4.3 g, 56 percent.1 g (5.37 mmol) of ferrocene, dissolved in 12 ml of anhydrous ethyl ether, was treated with 7.2 ml (11.56 mmol) of n-BuLi (1.6M solution in hexane) and by addition of 1.74 ml (11.56 mmol) of N, N, N', N'-tetramethylethylenediamine. The reaction was left under argon and with stirring at ambient temperature for 20 hours. 1.33 ml (17.20 mmol) of DMF were added at -78° C. After stirring at -78° C. for 2 hours, the reaction mixture was hydrolyzed (15 ml of water). The aqueous phase was extracted with dichloromethane (3.x.15 ml). The resulting organic phase was dried over MgSO4 and was then concentrated. The residue was purified on silica gel with a pentane/ethyl acetate (50:50) mixture. [0152] 0.62 g (2.56 mmol, 48percent) of compound 1 was obtained in the form of a brown paste. [0153] 1H NMR (CDCl3): 4.62 (d, J=9 Hz, 4H, H2H3-H2'H3'), 4.83 (d, J=8.7 Hz, 4H, H1H4-H1'H4'), 9.89 (m, 2H, 2CHO) [0154] 13C NMR (CDCl3): 70.9 (C2H5), 74.20 (C3C4), 80.4 (C1), 192.9 (C6). [0155] MS: 185 (60), 243 (M+, 95).To a dry Schlenk flask was added 3.100 g (16.6 mmol) of vacuum dried ferrocene and 12.0 mL of n-hexane, Stirred to a suspension; then 25.0 mL of n-butyllithium (1.6 M, 40.0 mmo1)Then, 6.0 mL of tetramethylethylenediamine (40.0 mmo1) was added dropwise over a period of about 60 min, The reaction was continued for 16 h at room temperature; the resulting mixture was filtered, The resulting orange-red powder was washed three times with 15.0 mL of n-hexane, i.e., about 15.0 mmo1 of 1, 1'-bis-lithium ferrocene, To this was added 35.0 mL of n-hexane, Stirred to a suspension; another 12 mL of anhydrous ether was added 2.8 mL (36.0 mmo1) of dimethylformamide, The solution was added dropwise to the suspension (about 30 min) under ice-water bath cooling. After the dropwise addition, the ice-water bath was removed and allowed to warm to room temperature and stirred for about 30 minutes.Add 50.0 mL (4.0 M, 0.2 mol) of hydrochloric acid, Continue to react for 15 min after static, set stratification, The aqueous layer was extracted three times with 15.0 mL of dichloromethane, A dark red solid ferrocene dialdehyde was obtained 3.363 g.