The products of aza-type Michael addition, i.e., β-amino carbonyl compounds and their derivatives, are often used as peptide analogs or precursors of optically active amino acids, amino alcohols, diamines, and lactams [1]. Moreover, β-amino carbonyl functionalities are ubiquitous motifs in natural products such as alkaloids and polyketides [2]. Herein, we report the synthesis of new product using aza-type Michael reactions under mild conditions.
A mixture of 3-(benzylamino)propionitrile 1 [3] (1g, 6.25mmol) and 1-hydroxymethyl-3,5-dimethyl pyrazole 2 [4] (0.79g, 6.25 mmol) in 20 ml of acetonitrile was stirred at room temperature for four days, then the mixture was dried with Na2SO4 and filtered. The solvent was evaporated under reduced pressure. The product 3 obtained with a 97% yield as yellow oil.
1H-NMR (300 MHz, CDCl3): δ= 7.31-7.37 (CHarom, 5H, m); 4.80 ( N-CH2-N, 2H, s); 3.75 (C6H5-CH2,2H, s); 2.98-3.02 (CH2-CH2-CN, 2H, t, J = 7.66 Hz) ; 2.31-2.35 ( N-CH2, t, J = 7.66 Hz); 2.22 ( CH3, 3H, s) and 2.15 ( CH3, 3H, s).
13C-NMR (CDCl3, 75 MHz): δ= 148.18 (l); 140.5 (j); 138.12 (e); 129.11 (f); 128.99 (g); 128.03 (h); 119.27 (a); 106.35 (k); 66.56 (i); 56.94 (d); 48.24 (c); 17.23 (b); 13.95 (m); 11.46 (n).
EI-MS (70 eV, m/z): 173 (17.4); 171; 119; 95; 91 (100).
Supplementary materials
Supplementary File 1Supplementary File 2Supplementary File 3References
- Fustero, S.; Pina, B.; Salavert, E.; Navarro, A.; Ramirez de Arellano, M. C.; Fuentes, A. S. J. Org. Chem. 2002, 67, 4667. [PubMed]
- Arend, M.; Westermann, B.; Risch, N. Angew. Chem., Int. Ed 1998, 37, 1045.
- Xu, L.W.; Li, L.; Xia, C.-G. Helvetica Chimica Acta 2004, 87, 1522. [PubMed]Azizi, N.; Saidi, M. R. Tetrahedron 2004, 60, 383.
- Dvoretzky, I.; Richte, G. H. J. Org. Chem. 1950, 15, 1285.
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