Synthesis
Typical reactions were carried out under microwave radiation conditions. A mixture of 2-cyanopyridine (10 mmol), ethylenediamine (40 mmol) and Cu(II)-(IAA)2 (2.0 mmol) was placed in a microwave reactor and irradiated with pulses at a power of 1000 W for 5-20 min. The reaction process was monitored by thin layer chromatography (TLC) with an eluent ratio of ethyl acetate/methanol (3:1). Upon completion of the reaction, the mixture was cooled to room temperature and diluted by addition of dichloromethane (CH2Cl2), followed by filtration to remove the catalyst. The solvent was removed by rotary evaporation to give almost pure 2-(4,5-dihydro-1H-imidazol-2-yl)pyridine. For further purification, the standard method for the synthesis of imidazolines under reflux conditions can be used. The structure of the product was confirmed by melting point (mp), nuclear magnetic resonance hydrogen spectroscopy (1H NMR), mass spectrometry (MS) and infrared spectroscopy (IR) data.
References
[1] Journal of the Serbian Chemical Society, 2012, vol. 77, # 9, p. 1181 - 1189,9
[2] Canadian Journal of Chemistry, 2010, vol. 88, # 2, p. 135 - 141
[3] Monatshefte fur Chemie, 2007, vol. 138, # 6, p. 579 - 583
[4] Tetrahedron Letters, 2011, vol. 52, # 14, p. 1578 - 1582
[5] Tetrahedron Letters, 2006, vol. 47, # 13, p. 2129 - 2132
