Synthesis of 2-Substituted 7,7-dimethyl-5-oxo-5,6,7,8-tetrahydroquinoline- 4-carboxylic acids

Article abstract of DOI:10.1134/S1070428012060097

2-Substituted 7,7-dimethyl-5-oxo-5,6,7,8-tetrahydroquinoline-4-carboxylic acids were synthesized by reaction of acyl- and aroylpyruvic acids with 3-amino-5,5-dimethylcyclohex-2-en-1-one. A plausible mechanism of their formation was proposed on the basis of ab initio quantum-chemical calculations.

Full text of DOI:10.1134/S1070428012060097

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2012, Vol. 48, No. 6, pp. 799–803. © Pleiades Publishing, Ltd., 2012.
Original Russian Text © D.A. Rudenko, S.N. Shurov, M.I. Kodess, M.A. Ezhikova, A.N. Vasyanin, 2012, published in Zhurnal Organicheskoi Khimii, 2012,
Vol. 48, No. 6, pp. 803–807.
Synthesis of 2-Substituted 7,7-Dimethyl-5-oxo-5,6,7,8-tetrahydro-
quinoline-4-carboxylic Acids
D. A. Rudenkoa, S. N. Shurova, M. I. Kodessb, M. A. Ezhikovab, and A. N. Vasyanina
a Perm State National Research University, ul. Bukireva 15, Perm, 614990 Russia
e-mail: seshurov@yandex.ru
b Postovskii Institute of Organic Synthesis, Ural Division, Russian Academy of Sciences,
ul. S. Kovalevskoi/Akademicheskaya 22/20, Yekaterinburg, 620990 Russia
Received November 30, 2011
Abstract—2-Substituted 7,7-dimethyl-5-oxo-5,6,7,8-tetrahydroquinoline-4-carboxylic acids were synthesized
by reaction of acyl- and aroylpyruvic acids with 3-amino-5,5-dimethylcyclohex-2-en-1-one. A plausible
mechanism of their formation was proposed on the basis of ab initio quantum-chemical calculations.
DOI: 10.1134/S1070428012060097
It was found previously [1] that aroylpyruvic acids
I react with aromatic amines to give 4-aryl-2-aryl-
amino-4-oxobut-2-enoic acids as a result of attack by
the amino nitrogen atom on C2 in substrate I. While
continuing studies on chemical properties of aroyl-
pyruvic acids, in the present work we examined their
reaction with a difunctional 1,3-nucleophile, 3-amino-
5,5-dimethylcyclohex-2-en-1-one (II), which is a cy-
clic enamino ketone. Taking into account the results of
our previous studies, the reaction of acids Ia–Ih with
enamino ketone II was expected to produce 4-aryl-2-
(5,5-dimethyl-3-oxocyclohex-1-en-1-ylamino)-4-oxo-
but-2-enoic acids (III) or their cyclization products IV.
However, by heating equimolar amounts of acyl- or
aroylpyruvic acids Ia–Ih and enamino ketone II in
boiling acetonitrile over a period of 1 h we obtained
2-substituted 7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-
quinoline-4-carboxylic acids Va–Vh (Scheme 1).
spectrum a cross peak with ortho-protons in the phenyl
substituent (δ 8.23 ppm), which unambiguously con-
firms structure V. Signals from methylene groups were
also identified by 2D HMBC experiments: protons in
the C8H2 group showed cross peaks with C4a
(δC 121.01 ppm) and C8a (δC 162.82 ppm) as a result of
coupling through three and two bonds, respectively,
whereas protons on C6 revealed couplings with C4a and
C5 (δC 196.34 ppm). The corresponding carbon signals
(C6 and C8) were identified in the 2D HSQC spectra by
1
direct JCH couplings; likewise, signals from the other
carbon atoms linked to protons were assigned.
A probable scheme of formation of quinolinecar-
boxylic acids Va–Vh involves initial formation of C–C
bond as a result of interaction between C2 in acid I and
C2 in enamino ketone II. Intermediate A thus formed is
stabilized via proton migration from the nitrogen atom
to C3 in the acid residue (intermediate B). Intermediate
B loses water molecule, yielding intermediate C, and
enolization of the latter gives intermediate D. Intra-
molecular attack by the nitrogen atom in D on the
vinylic carbon atom leads to closure of pyridine ring
(intermediate E), and dehydration of E yields final
product V.
With a view to substantiate the proposed scheme,
we performed ab initio quantum-chemical calculations
[6-31G(d) basis set] of the total energies (Etot), bond
lengths, bond and dihedral angles, charges on atoms,
and orders of bonds in intermediates A–E for acid Vb.
We also simulated the transformations Ib + II → A
The elemental composition of the products equally
conforms to structures IV and V. Their IR and
1H NMR spectra do not contradict both structures but
they do not allow us to distinguish between structures
IV and V without ambiguity. Therefore, the product
structure was assigned on the basis of 13C NMR spec-
tra with the use of two-dimensional 1H–13C HSQC and
HMBC techniques. For instance, among two signals at
δC 159.43 and 143.57 ppm (C2 or C4) in the 13C NMR
spectrum of Vb, the downfield signal undoubtedly
belongs to C2 (as α-carbon atom in the pyridine ring).
Just that carbon atom displayed in the 2D HMBC
799

RUDENKO et al.
800
Scheme 1.
O
O
O
O
R
N
H
O
O
R
+
Me
Me
Me
–H2O
Me
Me
R
COOH
NH2
N
COOH
COOH
Me
H
Ia–Ih
II
III
IV
≠
≠
H
H
H
O
O
O
O
O
O
HOC(O)
O
HOC(O)
O
HOC(O)
O
R
R
R
H
H
H
H
Me
Me
Me
Me
Me
NH2
AC1
NH2
N
Me
H
A
AC2
H
O
H
O
O
O
OH
HO
O
O
O
O
HOC(O)
O
R
R
R
–H2O
Me
Me
Me
Me
H
NH
NH
Me
Me
NH
B
C
D
O
H
HO
O
O
O
COOH
N
O
COOH
N
R
–H2O
Me
Me
Me
Me
OH
Me
Me
NH
AC3
R
R
H
E
Va–Vh
I, V, R = t-Bu (a), Ph (b), 4-MeC6H4 (c), 4-MeOC6H4 (d), 4-EtOC6H4 (e), 4-BrC6H4 (f), 4-ClC6H4 (g), 1-naphthyl (h).
plex determining the character of reactant approach to
each other and intermediate A, and the maximum, to
activated complex AC1. The dipole–dipole complex is
formed via coordination of compounds Ib and II
through the hydrogen bond C1=O···H–O–C(O). No
appreciable variation of the geometric parameters of
the components compared to the isolated molecules
was observed. The calculated energy of the dipole–
and D → E by the reaction coordinate method; as reac-
tion coordinate we selected the interatomic distances
C2(I)–C2(II) and N(II)–C3(I), respectively. According
1
to the X-ray diffraction data [2] and H NMR spectra,
compound Ib has the structure of 2-hydroxy-4-oxo-4-
phenylbut-2-enoic acid both in the crystalline state and
in solution. Therefore, geometric parameters of just
that structure were set in the calculations.
Variation of the C2(I)···C2(II) distance from 5.100
to 1.550 Å through a step of 0.025 Å revealed energy
minima (Etot) at 5.000 and 1.620 Å and a maximum at
1.850 Å. Optimal structures were sought for in the
vicinity of these critical points. The observed minima
corresponded, respectively, to the dipole–dipole com-
Me
H
O
O
O
Me
R
O
O
NH2
H
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 48 No. 6 2012

SYNTHESIS OF 2-SUBSTITUTED 7,7-DIMETHYL-5-OXO-5,6,7,8-TETRAHYDRO...
801
dipole complex was –1122.6118 a.u. As the distance
between the reaction centers shortened, the energy of
supermolecule Ib···II increased up to an Etot value of
–1122.5737 a.u. in the transition state. The validity of
localization of the transition state on the reaction coor-
dinate was confirmed by the presence of one negative
Hessian eigenvalue. The interatomic distance
C2(I) ···C2(II) in activated complex AC1 was 1.864 Å,
and the order of that bond was 0.625. According to the
calculations, the benzoylpyruvic acid fragment (Ib)
retains hydrogen bond C2O–H · · · O=C4 1.747 Å.
Presumably, approach of the reactants to each other is
accompanied by electron density transfer from
enamino ketone II to acid Ib. Its magnitude was
estimated at 0.491 ē (according to Mulliken). The
largest gain in charge in the benzoylpyruvic acid frag-
ment (Ib) was observed for C3 (from –0.398 to –0.516)
and carbonyl oxygen atom in the benzoyl group (from
–0.642 to –0.805).
respectively, and relatively short distance between
them (3.353 Å). Intentional shortening of that distance
did not give rise to a stable structure. Therefore, we
presumed that intermediate C is converted into D via
proton transfer from the methylene carbon atom to
oxygen. Intermediate D (Etot = –1046.5757 a.u.) is sta-
bilized by intramolecular hydrogen bond C=O···H–O
(the calculated interatomic distance is 1.872 Å). The
distance between the reaction centers, nitrogen
(–0.679) and carbon atoms (0.449) is 4.039 Å. Ap-
proach of these centers to each other leads to activated
complex AC3 (Etot = –1046.5449 a.u.), in which the
N–C distance shortens to 2.212 Å. The distance
N–C 1.453 Å corresponds to intermediate E (Etot
=
–1046.6122 a.u.), whose dehydration yields final prod-
uct Vb (Etot = –970.6174 a.u.).
According to the calculations, both pyridine and
benzene fragments in molecule Vb are almost planar,
and they form a dihedral angle N1C2CαCo of 26.6°. The
C8 atom lies in the pyridine ring plane, and the C5, C6,
and C7 atoms deviate from that plane by 0.174, 0.272,
and 0.441 Å, respectively. The orientation of the
carboxy group is determined by the torsion angle
OCC4C4a which is equal to 107.1°.
The order of the C2(I)–C2(II) bond in zwitterionic
intermediate A increased to 0.859, and the number of
electrons “transferred” from molecule II to Ib in-
creased to 0.689. The charge on C3 slightly decreased
(to –0.507), and the charge on the benzoyl carbonyl
oxygen atom increased to –0.852.
Activated complexes AC1–AC3 were identified as
transition states taking into account the presence of one
negative eigenvalue in the corresponding Hessian
matrices. Hessian matrices calculated for intermediates
A–E had no negative eigenvalues.
We believe that stabilization of intermediate A
should involve proton transfer from the enamino
ketone fragment of II to the acid residue (Ib). The
interatomic distances are as follows: N–H(II) ···C3(I)
2.763, N–H(II) · · · O=C4(I) 3.189, C2H(II)–C3(I)
2.812 Å. In order to elucidate the way of stabilization
of intermediate A, we simulated proton transfer from
both nitrogen atom and C2 in the enamine fragment to
the acid residue by the reaction coordinate method, i.e.,
by successively extending the corresponding inter-
atomic distances. It was found that the proton attached
to C2 in the enamino ketone fragment is transferred to
the hydroxy oxygen atom in the carboxy group, which
is not the case. The proton on the nitrogen atom is
transferred to C3 in the acid residue, leading to inter-
mediate B through activated complex AC2. The cal-
culated total energy of AC2 is –1122.5667 a.u., i.e., the
activation barrier (the difference between the energies
of intermediate A and activated complex AC2) is
0.007 a.u. The N–H bond length in AC2 is 1.116 Å,
and the interatomic distance NH···C3 is 1.664 Å.
Compounds Va and Vc–Vh are likely to be formed
according to a similar mechanism.
EXPERIMENTAL
The IR spectra of compounds Va–Vh dispersed in
mineral oil were recorded on an FSM-1210 spectrom-
eter. The 1H and 13C NMR spectra were measured from
solutions in DMSO-d6 on a Bruker DRX-400 instru-
ment at 400 and 100 MHz, respectively, using tetra-
methylsilane as internal reference. Complete signal
assignment in the NMR spectra of Va–Vc and Vf was
1
made with the aid of two-dimensional H–13C HSQC
and HMBC techniques. The mass spectrum (electron
impact, 70 eV) of Vb was recorded on a Varian MAT
311A instrument with direct sample admission into the
ion source. The elemental compositions were deter-
mined on a LECO Corporation CHNS-932 analyzer.
Intermediate B (Etot = –1122.6445 a.u.) undergoes
dehydration to C (Etot = –1046.5964 a.u.). No N–C
bond is formed in C despite considerable charges on
the nitrogen and carbon atoms, –0.673 and 0.568,
Quantum-chemical calculations were performed
using Firefly software package [3] (Linux, CentOS 5.5
6×AMD Athlon X2 4800).
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 48 No. 6 2012

RUDENKO et al.
802
1
Acyl- and aroylpyruvic acids Ia–Ih were synthe-
(OH), 1722 (4-C=O), 1686 (C5=O). H NMR spec-
trum, δ, ppm: 1.07 s (6H, Me), 2.38 s (3H, MeC6H4),
2.59 s (2H, 6-H), 3.09 s (2H, 8-H), 7.33 d (2H, m-H,
J = 8.2 Hz), 8.13 d (2H, o-H, J = 8.2 Hz), 7.89 s (1H,
3-H), 13.5 br.s (1H, OH). 13C NMR spectrum, δC, ppm:
20.91 (Me), 27.67 (2C, Me), 32.46 (C7), 46.15 (C8),
51.39 (C6), 115.41 (C3), 120.75 (C4a), 127.22 (Cm),
129.54 (Co), 134.11 (Ci), 140.44 (Cp), 143.65 (C4),
159.39 (C2), 162.75 (C8a), 169.34 (COOH), 196.27
(C5). Found, %: C 73.61; H 5.99; N 4.53. C19H19NO3.
Calculated, %: C 73.77; H 6.19; N 4.53.
sized according to the procedure reported in [4], and
3-amino-5,5-dimethylcyclohex-2-en-1-one was pre-
pared as described in [5].
2-tert-Butyl-7,7-dimethyl-5-oxo-5,6,7,8-tetrahy-
droquinoline-4-carboxylic acid (Va). A mixture of
1.00 g (6 mmol) of acid Ia and 0.81 g (6 mmol) of
enamino ketone II in 30 ml of acetonitrile was heated
for 1 h under reflux. The mixture was cooled to 0°C,
and the precipitate was filtered off and recrystallized
from acetonitrile. Yield 1.11 g (70%), white crystals,
mp 227–228°C. IR spectrum, ν, cm–1: 3350 (OH),
2473 br (OH, assoc.), 1718 (4-C=O), 1681 (C5=O).
1H NMR spectrum, δ, ppm: 1.04 s (6H, Me), 1.32 s
(9H, t-Bu), 2.55 s (2H, 6-H), 3.01 s (2H, 8-H), 7.33 s
(1H, 3-H), 13.3 br.s (1H, OH). 13C NMR spectrum, δC,
ppm: 27.66 (Me), 29.56 (Me3C), 32.46 (C7), 37.91
(CMe3), 46.11 (C8), 51.36 (C6), 115.14 (C3), 120.09
(C4a), 142.75 (C4), 161.57 (C8a), 169.55 (COOH),
173.52 (C2), 196.47 (C5). Found, %: C 69.82; H 7.56;
N 5.12. C16H21NO3. Calculated, %: C 69.79; H 7.69;
N 5.09.
2-(p-Methoxyphenyl)-7,7-dimethyl-5-oxo-5,6,7,8-
tetrahydroquinoline-4-carboxylic acid (Vd) was
synthesized from 1.55 g (7 mmol) of acid Id and
0.97 g (7 mmol) of II. Yield 1.52 g (67%), light yellow
crystals, mp 271–273°C. IR spectrum, ν, cm–1: 2461 br
(OH, assoc.), 1720 (4-C=O), 1679 (C5=O). H NMR
1
spectrum, δ, ppm: 1.07 s (6H, Me), 2.59 s (2H, 6-H),
3.08 s (2H, 8-H), 3.84 s (3H, OMe), 7.07 d (2H, m-H,
J = 9.0 Hz), 7.85 s (1H, 3-H), 8.22 d (2H, o-H, J =
9.0 Hz), 13.4 br.s (1H, OH). 13C NMR spectrum, δC,
ppm: 27.68 (Me), 32.44 (C7), 46.18 (C8), 51.39 (C6),
55.32 (OMe), 114.30 (Cm), 114.87 (C3), 120.30 (C4a),
128.96 (Co), 129.27 (Ci), 143.49 (C4), 159.15 (C2),
161.35 (Cp), 162.73 (C8a), 169.40 (COOH), 196.19
(C5). Found, %: C 70.00; H 5.62; N 4.40. C19H19NO4.
Calculated, %: C 70.14; H 5.89; N 4.30.
Compounds Vb–Vh were synthesized in a similar
way.
7,7-Dimethyl-5-oxo-2-phenyl-5,6,7,8-tetrahydro-
quinoline-4-carboxylic acid (Vb) was synthesized
from 1.38 g (7 mmol) of acid Ib and 1.00 g (7 mmol)
of II. Yield 1.91 g (91%), white crystals, mp 252–
253°C. IR spectrum, ν, cm–1: 3365 (OH), 1719
2-(4-Ethoxyphenyl)-7,7-dimethyl-5-oxo-5,6,7,8-
tetrahydroquinoline-4-carboxylic acid (Ve) was
synthesized from 1.05 g (4 mmol) of acid Ie and 0.60 g
(4 mmol) of II. Yield 1.00 g (67%), yellow crystals,
mp 276–277°C. IR spectrum, ν, cm–1: 3344 (OH),
1
(4-C=O), 1690 (C5=O). H NMR spectrum, δ, ppm:
1.08 s (6H, Me), 2.61 s (2H, 6-H), 3.12 s (2H, 8-H),
7.51–7.56 m (3H, m-H, p-H), 7.95 s (1H, 3-H),
8.23 d.d (2H, o-H, J = 7.6, 2.2 Hz), 13.5 br.s (1H, OH).
13C NMR spectrum, δC, ppm: 27.66 (Me), 32.47 (C7),
46.12 (C8), 51.38 (C6), 115.83 (C3), 121.01 (C4a),
127.29 (Co), 128.91 (Cm), 130.52 (Cp), 136.83 (Ci),
143.57 (C4), 159.43 (C2), 162.82 (C8a), 169.23
(COOH), 196.34 (C5). Mass spectrum, m/z (Irel, %):
295 (100) [M]+·, 286 (6.3) [M – CH3]+, 267 (5.1) [M –
CO]+·, 251 (74.9) [M – CO2]+·, 239 (42.4) [M – C4H8]+·,
233 (60.8) [M – CO – CO2]+·, 211 (13.3) [M –
Me2C=CHCHO]+·, 195 (72.7) [M – C4H8 – CO2]+·,
167 (12.1) [M – C4H8 – CO – CO2 ]+·. Found, %:
C 73.11; H 5.70; N 4.75. C18H17NO3. Calculated, %:
C 73.20; H 5.76; N 4.74. M 295.33.
1720 (4-C=O), 1681 (C5=O). H NMR spectrum, δ,
1
ppm: 1.07 s (6H, Me), 1.36 t (3H, CH3CH2, J =
6.9 Hz), 2.58 s (2H, 6-H), 3.08 s (2H, 8-H), 4.11 q
(2H, OCH2, J = 6.9 Hz), 7.05 d (2H, m-H, J = 8.8 Hz),
7.85 s (1H, 3-H), 8.19 d (2H, o-H, J = 8.8 Hz),
13.4 br.s (1H, OH). 13C NMR spectrum, δC, ppm: 14.56
(CH3CH2), 27.68 (Me), 32.45 (C7), 46.16 (C8), 51.37
(C6), 63.29 (OCH2), 114.69 (Cm), 114.81 (C3), 120.24
(C4a), 128.95 (Co), 129.07 (Ci), 143.47 (C4), 159.13
(C2), 160.64 (Cp), 162.71 (C8a), 169.36 (COOH),
196.19 (C5). Found, %: C 70.60; H 6.05; N 4.06.
C20H22NO4. Calculated, %: C 70.78; H 6.24; N 4.13.
2-(4-Bromophenyl)-7,7-dimethyl-5-oxo-5,6,7,8-
tetrahydroquinoline-4-carboxylic acid (Vf) was
synthesized from 2.00 g (7 mmol) of acid If and 1.00 g
(7 mmol) of II. Yield 2.23 g (85%), colorless crystals,
mp 256–257°C. IR spectrum, ν, cm–1: 3345 (OH),
2445 br (OH, assoc.), 1725 (4-C=O), 1681 (C5=O).
7,7-Dimethyl-2-(4-methylphenyl)-5-oxo-5,6,7,8-
tetrahydroquinoline-4-carboxylic acid (Vc) was
synthesized from 1.50 g (7 mmol) of acid Ic and 1.00 g
(7 mmol) of II. Yield 2.00 g (90%), lustrous colorless
crystals, mp 257–259°C. IR spectrum, ν, cm–1: 3354
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SYNTHESIS OF 2-SUBSTITUTED 7,7-DIMETHYL-5-OXO-5,6,7,8-TETRAHYDRO...
803
1H NMR spectrum, δ, ppm: 1.07 s (6H, Me), 2.61 s
(2H, 6-H), 3.11 s (2H, 8-H), 7.72 d (2H, o-H, J =
8.6 Hz), 7.99 s (1H, 3-H), 8.19 d (2H, m-H, J =
8.6 Hz), 13.7 br.s (1H, OH). 13C NMR spectrum, δC,
ppm: 27.66 (Me), 32.45 (C7), 46.06 (C8), 51.37 (C6),
115.87 (C3), 121.24 (C4a), 124.38 (Cp), 129.29 (Co),
131.88 (Cm), 135.98 (Ci), 143.78 (C4), 158.21 (C2),
162.88 (C8a), 169.16 (COOH), 196.29 (C5). Found, %:
C 57.40; H 3.99; N 3.68. C18H16BrNO3. Calculated, %:
C 57.77; H 4.31; N 3.74.
mp 246–247°C. IR spectrum, ν, ν, cm–1: 2463 br (OH,
1
assoc.), 1720 (4-C=O), 1681 (C5=O). H NMR spec-
trum, δ, ppm: 1.11 s (6H, Me), 2.67 s (2H, 6-H), 3.15 s
(2H, 8-H), 7.58 m (2H, 6′-H, 7′-H), 7.63 s (1H, 3-H),
7.64 d.d (1H, 3-H, J = 8.2, 7.2 Hz), 7.71 d.d (1H, 2′-H,
J = 7.2, 1.2 Hz), 8.04 m (1H, 5′-H or 8′-H), 8.08 d.t
(1H, 4′-H, J = 7.2, 1.0 Hz), 8.13 m (1H, 8′-H or 5′-H),
13.5 br.s (1H, OH). 13C NMR spectrum, δC, ppm:
27.68 (Me), 32.51 (C7), 46.00 (C8), 51.42 (C6), 120.42
(C3), 120.87 (C4a); 125.05, 125.37, 126.16, 126.90,
128.04, 128.42, 129.75, 130.17, 133.42, 136.38
(C10H7), 143.08 (C4), 162.42 and 162.57 (C8a, C2),
169.06 (COOH), 196.56 (C5). Found, %: C 76.28;
H 5.52; N 4.15. C22H19NO3. Calculated, %: C 76.50;
H 5.54; N 4.06.
2-(4-Chlorophenyl)-7,7-dimethyl-5-oxo-5,6,7,8-
tetrahydroquinoline-4-carboxylic acid (Vg) was
synthesized from 1.37 g (6 mmol) of acid Ig and
0.84 g (6 mmol) of II. Yield 1.40 g (70%), colorless
lustrous crystals, mp 252–254°C. IR spectrum, ν,
cm–1: 3360 (OH), 2462 br (OH, assoc.), 1711 (4-C=O),
1
1687 (C5=O). H NMR spectrum, δ, ppm: 1.08 s (6H,
REFERENCES
Me), 2.62 s (2H, 6-H), 3.11 s (2H, 8-H), 7.59 d (2H,
o-H, J = 8.6 Hz), 7.99 s (1H, 3-H), 8.26 d (2H, m-H,
J = 8.6 Hz), 13.7 br.s (1H, OH). 13C NMR spectrum,
δC, ppm: 27.66 (Me), 32.45 (C7), 46.07 (C8), 51.37
(C6), 115.90 (C3), 121.20 (C4a), 128.94 and 129.06 (Co,
Cm), 135.46 and 135.62 (Cp, Ci), 143.76 (C4), 158.12
(C2), 162.86 (C8a), 169.15 (COOH), 196.28 (C5).
Found, %: C 65.76; H 4.71; N 3.99. C18H16ClNO3.
Calculated, %: C 65.56; H 4.89; N 4.25.
1. Andreichikov, Yu.S., Kozlov, A.P., and Voronova, L.A.,
Zh. Org. Khim., 1978, vol. 14, p. 1559.
2. Aliev, Z.G., Shurov, S.N., Nekrasov, D.D., Podvin-
tsev, I.B., and Atovmyan, L.O., Zh. Strukt. Khim., 2000,
vol. 46, p. 1255.
3. Granovsky, A.A., Firefly version 7.1.G; http://
classic.chem.msu.su/gran/firefly/index.html (02.11.2011).
4. Andreichikov, Yu.S., Metody sinteza biologicheski aktiv-
nykh geterotsiklicheskikh soedinenii (Methods of Syn-
thesis of Biologically Active Heterocyclic Compounds),
Perm: Perm. Gos. Univ., 1989, p. 9.
7,7-Dimethyl-2-(1-naphthyl)-5-oxo-5,6,7,8-tetra-
hydroquinoline-4-carboxylic acid (Vh) was synthe-
sized from 1.62 g (7 mmol) of acid Ih and 0.97 g
(7 mmol) of II. Yield 1.83 g (76%), yellow crystals,
5. Zymalkowski, F. and Rimek, H., Arch. Pharm., 1961,
p. 759.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 48 No. 6 2012