Synthesis
General procedure for the synthesis of N,N-dimethylamino-1-ferrocenylethylamine from 1-(2-hydroxyethyl)ferrocene and dimethylamine: (3) (S)-1-ferrocenylethanol (1.03 kg, 4.47 mol), dichloromethane (3.0 L), and triethylamine (902.9 g, 8.94 mol) prepared above were added to the reaction vessel sequentially. Acetic anhydride (683.4 g, 6.70 mol) was slowly added dropwise at room temperature and the reaction was stirred for 3 hours. Subsequently, 33% aqueous dimethylamine solution (4.31 kg) was slowly added and stirring was continued for 5 hours. Upon completion of the reaction, the layers were left to separate and the organic phase was concentrated to recover the dichloromethane. The residue was purified by reduced pressure distillation and the fraction at 110 °C (0.07 kPa) was collected to give (S)-N,N-dimethyl-1-ferrocenylethylamine (1.02 kg) as a dark red oily liquid in 89% yield, 98% HPLC purity and 96% ee value.
References
[1] Patent: CN108409802, 2018, A. Location in patent: Paragraph 0050; 0053
[2] Canadian Journal of Chemistry, 1983, vol. 61, p. 2354 - 2358
[3] Bulletin de la Societe Chimique de France, 1972, p. 2847 - 2854
[4] Tetrahedron Letters, 1971, p. 1561 - 1563
[5] , Gmelin Handbook: Fe: Org.Verb.A4, 5.1.4.1.3.3, page 52 - 55,