Milata Viktor* and Kada Rudolf
Department of Organic Chemistry, Faculty of
Chemical Technology, Slovak University of Technology,
Radlinskeho 9, SK-812 37 Bratislava, Slovak Republic.
Tel.
00421-7-368 560, 395 410, Fax 00421-7-368 560 ([email protected],
[email protected] or [email protected])
Received: 7 May 1997 / Published: 26 May 1997
Symmetrically substituted bis(azolyl)methanes are often prepared from azoles in dichloromethane under PTC conditions [1]. Unsymmetrically substituted 1-benztriazolylmethanes can be prepared from 1-hydroxymethylbenzotriazole [2] via nucleophilic substitution with secondary amines, in this case, benzimidazole.
1-Hydroxymethylbenzotriazole (2.98 g, 20 mmol) was dissolved in warm ethanol (50 ml). Benzimidazole (2.36 g, 20 mmol) was then added and the mixture was heated at reflux temperature. The reaction was monitored by TLC. After the reaction had ended the reaction mixture was set aside at 5 deg.C overnight. The crystalline product was then collected, washed with cold ether and recrystallized from ethanol. Yield 4.18 g (84.0 %) of a white crystalline powder.
M.p. 92-93 deg.C.
TLC (EtOAc): Rf 0.30.
1H NMR (CDCl3): 8.28 (s, 1H, -CH=), 7.00-8.13 (m, 8H, Harom), 6.05 (s, 1H, CH2), 5.63 (s, 1H, CH2).
IR (cm-1, KBr): 3179, 3115, 3096, 3063, 3001, 2965, 2863, 2797, 2741, 1458, 1408, 1306, 1273, 1246, 1235, 1159, 1076, 783, 768, 747, 619.
UV (lmax/log e, methanol): 244/3.03, 250/3.05, 272/3.09, 279/3.06.
Anal. calc. for C14H11N5 (249.0): C 67.47, H 4.42, N 28.10; found: C 67.17, H 4.30, N 27.84.
Acknowledgements: The authors would like to thank Slovak Grant Agency (financial support No. 95/5195/202).
References and Notes
1. Julia, S.; Sala, P.; del Mazo, J.; Sancho, M.; Ochoa, C.; Elguero, J.; Fayet, J. P.; Vertut. M. C. N-Polyazo- lylmethanes. 1. Synthesis and NMR study of N,N-diazolylmethanes. J. Heterocycl. Chem. 1982, 19, 1141.
2. Fries, K.; Guterbock, H.; Kuhn, H.; Untersuchungen in der Reihe des Azimidobenzols und des N-Methyl-Azimidobenzols. Ann. 1934, 511, 213.
Sample Availability: Available from the author, 2g.©1997 MDPI. All rights reserved