RSS-Feed abonnieren
Bitte kopieren Sie die angezeigte URL und fügen sie dann in Ihren RSS-Reader ein.
https://www.thieme-connect.de/rss/thieme/de/10.1055-s-00000083.xml
Synlett 2004(10): 1832-1834
DOI: 10.1055/s-2004-829555
DOI: 10.1055/s-2004-829555
LETTER
© Georg Thieme Verlag Stuttgart · New York
Ytterbium Triflate Promoted Synthesis of Benzimidazole Derivatives
Weitere Informationen
Received
24 March 2004
Publikationsdatum:
15. Juli 2004 (online)
Publikationsverlauf
Publikationsdatum:
15. Juli 2004 (online)
![](https://www.thieme-connect.de/media/synlett/200410/lookinside/thumbnails/10.1055-s-2004-829555-1.jpg)
Abstract
Differently substituted benzimidazoles have been synthesised in very good yields in solvent-free conditions from o-phenylenediamine and aldehydes in the presence of Yb(OTf)3 as catalyst. The method is applicable to aromatic, unsaturated and aliphatic aldehydes and to substituted o-phenylenediamines without significant differences.
Key words
aldehydes - benzimidazoles - catalysis - lanthanides
- 1
Velik J.Baliharova V.Fink-Gremmels J.Bull S.Lamka J.Skalova L. Res. Vet. Sci. 2004, 76: 95 - 2
Yadagiri B.Lown JW. Synth. Commun. 1990, 20: 955 - 3
Sun Q.Yan B. Bioorg. Med. Chem. Lett. 1998, 8: 361 - 4
Preston PN. Benzimidazoles and Congeneric Tricyclic Compounds, In The Chemistry of Heterocyclic Compounds Part 1 Vol. 40:Weissberger A.Taylor EC. Wiley; New York: 1981. p.6-60 - 5
Grimmett MR. Imidazoles and their Benzo Derivatives, In Comprehensive Heterocyclic Chemistry Vol. 5:Katritzky AR.Rees CW. Pergamon; Oxford: 1984. p.457-487 - 6
Benincori T.Sannicolò F. J. Heterocycl. Chem. 1988, 25: 1029 - 7
Smith JG.Ho I. Tetrahedron Lett. 1971, 38: 3541 - 8
Weidenhagen R. Ber. 1936, 69: 2263 - 9
Jakobson P.Jannicke M.Meyer F. Ber. 1896, 29: 2682 - 10
Stevens FF.Bower JD. J. Chem. Soc. 1949, 2971 - 11
Kobayashi S.Sugiura M.Kitagawa H.Lam WWL. Chem. Rev. 2002, 6: 2227 - 12
Curini M.Epifano F.Marcotullio MC.Rosati O. Tetrahedron Lett. 2001, 42: 3193 - 13
Typical Procedure.
A mixture of o-phenylenediamine (1 mmol) and aldehyde (1.1 mmol) was well stirred with Yb(OTf)3 (0.05 mmol) at r.t. for 30 min. To this solution, CH2Cl2 (2 mL) was added to get Yb(OTf)3 crystallized; the catalyst was removed by filtration under reduced pressure and the residue was purified by SiO2 gel column chromatography using CH2Cl2-MeOH 99:1 as eluent. Compounds 1, 2, 3, 5, 6, 7, 8, 9 and 10 were identified by comparison with commercial samples.
2-(2,6-dimethylhept-5-enyl)-1
H
-benzimidazole (
4). White solid; mp 93-94 °C. 1H NMR (200 MHz, CDCl3): δ = 1.01 (d, 6 H, J = 6.6 Hz), 1.27-2.27 (m, 5 H), 2.67-3.10 (m, 2 H), 5.01-5.21 (m, 1 H), 6.75 (s, 1 H), 7.15-7.65 (m, 4 H). 13C NMR (50 MHz, CDCl3): δ = 18.9, 19.5, 25.5, 25.6, 32.9, 36.9, 37.0, 116.7, 120.2, 122.1, 124.2, 136.3, 142.6, 146.6, 154.2. GC-MS: m/z = 242 [M+]. Anal. Calcd for C16H22N2: C, 79.29; H, 9.15; N, 11.56. Found: C, 79.31; H, 9.16; N, 11.54
- 15
Jerchel D.Fischer H.Kracht M. Ann. Chem. 1952, 575: 162
References
The reaction to yield compound 1 has been repeated three times, through the catalyst washed with CH2Cl2 and dried for 2 h at 70 °C with the following yields: 94%, 91%, and 91%.