Chemistry of Heterocyclic Compounds, Vol. 47, No. 9, December, 2011 (Russian Original Vol. 47, No. 9, September, 2011)
THREE-COMPONENT REACTION OF PERIMIDINES
WITH ACETOPHENONE AND SODIUM NITRITE
IN POLYPHOSPHORIC ACID
A. V. Aksenov1*, A. S. Lyakhovnenko1, N. A. Aksenov1,
A. N. Spicin1, and I. V. Aksenova1
Keywords: acetophenone, 1,3-diazapyrenes, perimidines, polyphosphoric acid, sodium nitrite, 1,3,6-tri-
azapyrenes, peri annelation.
Many organic luminophors and dyes are polynuclear aromatic and heteroaromatic compounds
derivatives including pyrene and its heterocyclic analogs. Efficient medicines are also found in this series of
compounds [1-3]. The main part of azapyrenes remain unavailable at this time. This is principally due to the
absence of efficient methods for the peri annelation of heterocyclic rings. In this study we propose a method for
the peri annelation of an [a,b]pyridine ring to perimidines based on a three-component reaction of the latter with
carbonyl compounds and sodium nitrite in polyphosphoric acid (PPA).
It was found that the reaction of the perimidines 1a,b [4] with acetophenone (2), and NaNO2 in PPA
gave a mixture of the previously unknown 8-phenyl-1,3,6-triazapyrenes 4a,b and 6,8-diphenyl-1,3-diazapyrenes
5a,b in the ratio 1.5:1 (1H NMR spectroscopic data) and in overall 68-74% yield.
It is likely that the reaction occurs in the following way: in the first stage the acetophenone is nitrosated
and the formed nitroso ketone 3 alkylates the perimidines 1a,b to give compounds 6a,b. Further reaction occurs
by the two possible routes A or B. Route A involves dehydration to give the unsaturated nitroso compounds
7a,b which yield the 1,3,6-triazapyrenes 4a,b in the final step. In route B a molecule of water is lost to give the
cyanohydrins 8a,b which then lose a molecule of HCN to give the ketones 9a,b. As it is known [5], the latter
react with acetophenone to give the diazapyrenes 5a,b.
1H NMR spectra were recorded on a Bruker WP-200 (200 MHz) instrument using TMS as internal
standard. Monitoring of the reaction course and the purity of the compounds synthesized was carried out on
Silufol UV-254 plates using ethyl acetate (4a, 5a) or ethyl acetate–petroleum ether (1:1) (4b, 5b) as eluents.
Preparative TLC was performed on Merck (Art. 5629) plates with a fluorescent indicator in the system ethyl
acetate–petroleum ether (1:1). The PPA used contained 86% P2O5 and was prepared by the method described in [6].
Synthesis of Triazapyrenes 4a,b and Diazapyrenes 5a,b (General Method). A mixture of the
corresponding perimidine 1a or 1b (1 mmol), acetophenone (0.18 g, 1.5 mmol), and NaNO2 (0.1 g, 1.45 mmol)
in PPA (2-3 g) was heated at 75-85ºC for 6 h. For separation of the pure materials the reaction mixture was
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*To whom correspondence should be addressed, e-mail: k-biochem-org@stavsu.ru, alexaks05@rambler.ru.
1Stavropol State University, 1 Pushkin St., Stavropol 355009, Russia.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1433-1436, September, 2011.
Original article submitted June 27, 2011.
0009-3122/11/4709-1185©2011 Springer Science+Business Media, Inc.
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