Synthesis 2006(9): 1549-1555  
DOI: 10.1055/s-2006-926444
FEATUREARTICLE
© Georg Thieme Verlag Stuttgart · New York

Synthesis and Spectroscopic Properties of 4a,14a-Diazoniaanthra[1,2-a]anthracene and 13a,16a-Diazoniahexaphene Derived from 1,7-Dimethylnaphthalene

Anton Granzhana, Jan W. Batsb, Heiko Ihmels*a
a Institut für Organische Chemie II, Universität Siegen, Adolf-Reichwein-Str. 2, 57068 Siegen, Germany
b Institut für Organische Chemie und Chemische Biologie, Johann-Wolfgang-Goethe-Universität Frankfurt, Marie-Curie-Str. 11, 60439 Frankfurt am Main, Germany
Fax: +49(271)7404052; e-Mail: ihmels@chemie.uni-siegen.de;
Further Information

Publication History

Received 23 February 2006
Publication Date:
12 April 2006 (online)

Abstract

An improved preparation of 1,7-dimethylnaphthalene is presented, which is used as a precursor for the synthesis of diazonia­hexacyclic salts, namely, 4a,14a-diazoniaanthra[1,2-a]anthracene (3) and 13a,16a-diazoniahexaphene (7). The influence of the reaction conditions on the formation of these isomers was investigated. Notably, the selectivity of the reactions depends significantly on the acid employed in the cyclization step. Both compounds exhibit similar absorption and fluorescence emission properties. Compound 3 exhibits a remarkable photopersistence in the solid state and in air-saturated aqueous solutions. However, diazoniahexaphene 7 undergoes rapid photodegradation in solution. X-ray diffraction analysis reveals that compound 3 adopts a helicene structure in the crystalline state.

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4,4-Dimethoxy-2-methyl-1-(2-tolyl)butan-2-ol: bp 90 °C/0.06 mbar; 1H NMR (400 MHz, CDCl3): δ = 1.21 (s, 3 H, C2-CH3), 1.80 (dd, 3 J = 5.0 Hz, 2 J = 14.3 Hz, 1 H, 3-Ha), 1.91 (dd, 3 J = 6.7 Hz, 2 J = 14.3 Hz, 1 H, 3-Hb), 2.36 (s, 3 H, Ar-CH3), 2.78 (d, 2 J = 13.7 Hz, 1 H, 1-Ha), 2.86 (d, 2 J = 13.7 Hz, 1 H, 1-Hb), 3.16 (s, 1 H, OH), 3.32 (s, 3 H, OMea), 3.35 (s, 3 H, OMeb), 4.68 (dd, 3 J = 5.0 Hz, 3 J = 6.7 Hz, 1 H, 4-H), 7.11-7.16 (complex m, 4 H, Ar-H); 13C NMR (100 MHz CDCl3): δ = 20.5 (CH3), 27.2 (CH3), 42.9 (CH2), 44.9 (CH2), 52.6 (CH3), 53.2 (CH3), 71.9 (Cq), 102.6 (CH), 125.4 (CH), 126.4 (CH), 130.4 (CH), 131.6 (CH), 135.9 (Cq), 137.4 (Cq).

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CCDC-298121 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via
www.ccdc.cam.ac.uk/data_request/cif.