ORGANIC
LETTERS
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Vol. XX, No. XX
000–000
From Blatter Radical to 7‑Substituted
1,3-Diphenyl-1,4-dihydrothiazolo[50,40:4,5]-
benzo[1,2‑e][1,2,4]triazin-4-yls: Toward
Multifunctional Materials
Andrey A. Berezin,† Christos P. Constantinides,† Chryssoula Drouza,‡ Maria Manoli,†
and Panayiotis A. Koutentis*,†
Department of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus,
and Department of Agricultural Science, Biotechnology and Food Science,
Cyprus University of Technology, 30 Archbishop Kyprianou Str., 3036 Limassol, Cyprus
Received October 1, 2012
ABSTRACT
A Blatter radical is oxidized to benzotriazin-7(H)-one which after amination and subsequent acyl- and aroylation gives N-(benzotriazin-6-yl)-
carboxamides that undergo ring closure with P2S5 to afford the corresponding thiazolo[50,40:4,5]benzo[1,2-e][1,2,4]triazin-4-yls. These highly
delocalized radicals are air stable and show good reversible electrochemical behavior.
Molecular materials with multifunctional properties are
candidates for new electronic devices.1 Stable organic
radicals can be building blocks for such materials because
they can combine tunable transport and magnetic pro-
perties, e.g., for organic spintronic devices.2a Difficulties,
however, in controlling their solid-state packing hinders
the successful tailoring of their macroscopic properties,
such as bulk ferromagnetism.2
Identifying “structureꢀmagnetism relationships” can
help unravel features that correlate structure and solid-
state packing to the resultant magnetic properties. For
example, extending the degree of spin delocalization3a can
lead to further stabilization of π radicals and could en-
hance desirable ferromagnetic exchange interactions in the
solid state.3b
1,3-Diphenyl-1,4-dihydro-1,2,4-benzotriazin-4-yl (2a)
(Blatter’s radical) is an air and moisture stable radical that
for decades did not receive much attention.4 So far benzo-
triazinyls form 1D-slipped π stacks in which the slippage
can help keep the net overlap of SOMOs at nearly zero
(orthogonal) to favor ferromagnetic interactions. For exam-
ple, 7-trifluoromethylbenzotriazinyl 2b is an exceptionally
† University of Cyprus.
‡ Cyprus University of Technology.
(1) (a) Lahti, P. M., Ed. Magnetic Properties of Organic Materials;
Marcel-Dekker Inc.: New York, 1999. (b) Itoh, K.; Kinoshita, M., Eds.
Molecular Magnetism: New Magnetic Materials; Kodansha and Gordon &
Breach: Tokyo and Amsterdam, 2000.
(2) (a) Ratera, I.; Veciana, J. Chem. Soc. Rev. 2012, 41, 303.
(b) Haynes, D. A. CrystEngComm 2011, 13, 4793. (c) Rakitin, O. A.
Russ. Chem. Rev. 2011, 80, 647. (d) Hicks, R. G. Org. Biomol. Chem.
2007, 5, 1321. (j) Nakatsuji, S.; Anzai, H. J. Mater. Chem. 1997, 7, 2161.
(e) Rawson, J. M.; Alberola, A.; Whalley, A. J. Mater. Chem. 2006, 16,
2575. (f) Mito, M.; Komorida, Y.; Tsuruda, H.; Tse, J. S.; Desgreniers,
S.; Ohishi, Y.; Leitch, A. A.; Cvrkalj, K.; Robertson, C. M.; Oakley,
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A. A.; Cvrkalj, K.; Myles, D. J. T.; Reed, R. W.; Dube, P. A.; Oakley,
R. T. J. Am. Chem. Soc. 2008, 130, 14791. (h) Leitch, A. A.; Brusso, J. L.;
Cvrkalj, K.; Reed, R. W.; Robertson, C. M.; Dube, P. A.; Oakley, R. T.
Chem. Commun. 2007, 3368. (i) Rajca, A. Chem. Rev. 1994, 94, 871.
(3) (a) Yoshizawa, K. Magnetic Properties of Organic Material;
Marcel-Dekker Inc.: New York, 1999; Chapter 19. (b) Yamaguchi, K;
Kawakami, T.; Oda, A; Yoshioga, Y. Magnetic Properties of Organic
Material; Marcel-Dekker Inc.: New York, 1999; Chapter 20.
(4) (a) Blatter, H. M.; Lukaszewski, H. Tetrahedron Lett. 1968, 9,
2701. (b) Krieger, C.; Neugebauer, F. A. Acta Crystallogr. 1996, C52,
3124. (c) Gubaidullin, A. T.; Buzykin, B. I.; Litvinov, I. A.; Gazetdinova,
N. G. Russ. J. Gen. Chem. 2004, 74, 939. (d) Mukai, K.; Inoue, K.; Achiwa,
N.; Jamali, J. B.; Krieger, C.; Neugebauer, F. A. Chem. Phys. Lett. 1994,
224, 569.
r
10.1021/ol302714j
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