Russian Chemical Bulletin, International Edition, Vol. 66, No. 11, pp. 2136—2141, November, 2017
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2136—2141, November, 2017.
10665285/17/66112136 © 2017 Springer Science+Business Media, Inc.
Synthesis and structure of 4,6di(tertbutyl)2(4chloro7,8dimethylquinolin2yl)
V. V. Tkachev,
Yu. A. Sayapin,
I. V. Dorogan,
A. A. Kolodina,
E. A. Gusakov,
V. N. Komissarov,
G. V. Shilov,
S. M. Aldoshin,
and V. I. Minkin
Institute of Problems of Chemical Physics, Russian Academy of Sciences,
1 prosp. Akad. Semenova, 142432 Chernogolovka, Moscow Region, Russian Federation.
Institute of Physical and Organic Chemistry, Southern Federal University,
194/2 prosp. Stachki, 344090 RostovonDon, Russian Federation.
Fax: +7 (863 2) 45 4700. Email: email@example.com
Southern Scientific Center, Russian Academy of Sciences,
41 ul. Chekhova, 344006 RostovonDon, Russian Federation.
Fax: +7 (863) 266 5677. Email: firstname.lastname@example.org
The reaction of 4chloro2,7,8trimethylquinoline with 4,6di(tertbutyl)3(piperidin
1ylmethyl)1,2benzoquinone, which was prepared by the in situ oxidation of 4,6di(tert
butyl)3(piperidin1ylmethyl)pyrocatechol with sodium nitrite, gave 4,6di(tertbutyl)2
(4chloro7,8dimethylquinolin2yl)7(piperidin1ylmethyl)1,3tropolone. Its structure
was determined by Xray diffraction. The energy and structural characteristics of the tauto
mers of this compound in the gas phase and in a polar solution were calculated by quantum
chemical methods (PBE0/6311+G(d,p)).
Kew words: 1,2benzoquinones, quinolines, 1,3tropolones, intramolecular hydrogen
bond, Xray diffraction, quantum chemical calculations.
Tropolone derivatives have attracted considerable in
terest due to high biological activity
and their poten
tial use as fluorescent sensors
and anchoring groups for
dyesensitized solar cells.
In particular, 2hetaryl1,3
tropolones exhibit various antibacterial
activities depending on the presence of functional sub
stituents in the tropolone ring. Hence, the development
of new methods for the synthesis of 1,3tropolones and
procedures for the introduction of functional groups into
tropolone ring is a challenging problem. The main method
of synthesis of 2(quinolin2yl)1,3tropolones is based
on the ring expansion of oquinone via the reaction of
1,2benzoquinones with 2methylquinolines.
The goal of this work was to study the ring expansion
of oquinone in the series of aminoalkylated 1,2benzo
quinones using the reaction of 4chloro2,7,8trimethyl
quinoline with 4,6di(tertbutyl)3(piperidin1ylmeth
aminoalkylation reaction of 3,5di(tert
butyl)pyrocatechol (1) was used to synthesize 4,6di(tert
(Scheme 1). 4,6Di(tertbutyl)3(piperidin1ylmethyl)
1,2benzoquinone (3) was prepared for the first time in
high yield (86%) by the oxidation of a solution of pyro
catechol 2 in dry dichloromethane with an excess of
) oxide (see Scheme 1). 1,2Benzoquinone 3, which
was synthesized as darkbrown oil, crystallized over an
extended period of time in a desiccator over P