Transformations of schiff bases derived from quinoline-8-carbaldehyde. Synthesis of C-8 substituted quinolines

Article abstract of DOI:10.1002/jhet.5570380135

The Schiff bases derived from quinoline-8-carbaldehyde and substituted aromatic amines were used in the synthesis of C-8 substituted quinolines. 3-Aryl-2-(8-quinolinyl)-4-thiazolidinones were prepared from obtained aldimines by means of the cyclocondensat

Full text of DOI:10.1002/jhet.5570380135

Jan-Feb 2001
Transformations of Schiff Bases Derived From Quinoline-
8-carbaldehyde. Synthesis of C-8 Substituted Quinolines
Nüket Öcal*, Çigdem Yolaçan and S¸eniz Kaban
233
Yildiz Technical University, Faculty of Art and Sciences, Department of Chemistry, 80270 S¸is¸li, Istanbul, Turkey
*
Leonor Vargas M. and Vladimir Kouznetsov
Laboratory of Fine Organic Synthesis, School of Chemistry, Industrial University of Santander, A. A. 678, Bucaramanga, Colombia
Received May 10, 1999
The Schiff bases derived from quinoline-8-carbaldehyde and substituted aromatic amines were used in the
synthesis of C-8 substituted quinolines. 3-Aryl-2-(8-quinolinyl)-4-thiazolidinones were prepared from
obtained aldimines by means of the cyclocondensation of mercapto acids. A series of 4-N-arylamino-4-(8-
quinolinyl)-1-butenes was synthesized through the addition of the Grignard reagent (allylmagnesium bro-
mide) to the double bond C=N of these aldimines. The structure of the prepared compounds was established
on the basis of their elemental analyses and spectral data.
J. Heterocyclic Chem., 38, 233 (2001).
Introduction.
Diverse substituted quinolines have been synthesized for
a wide range of industrial, pharmaceutical, and biological
purposes [1,2]. Likewise, 4-thiazolidinones have shown
many useful applications. Generally, these compounds
have been shown to exhibit fungicidal, pesticidal, herbici-
dal, antitubercular, local anaesthetic and possible antimy-
cotic properties. They may also act as potential antiradia-
tion and chemotherapeutic agents [3-6]. The biological
significance of this kind of compounds urged us to study
the synthesis of some 3-aryl-2-(8-quinolinyl)-4-thiazolidi-
nones and 4-N-arylamino-4-(8-quinolinyl)-1-butenes due
to their possible biological activities. Moreover, these
latter homoallylamine derivatives are of particular interest
due to the rich and diverse chemistry of allyl and aryl-
amino groups. In this paper, we wish to describe the syn-
thesis of a series of new C-8 substituted quinolines.
Table 1
3-Aryl-2-(8-quinolinyl)-4-thiazolidinones 5-12
Compound No
R
X
Y
%
5
6
7
8
9
10
11
12
H
CH
H
CH
H
CH
H
OCH
OCH
H
H
H
H
CH
CH
H
61
94
57
78
42
32
62
57
3
3
3
3
3
3
CH
CH
CH
CH
Cl
3
3
3
3
3
3
Results and Discussion.
CH
Cl
H
For a long time imines have been used successfully in
the synthesis of nitrogen containing heterocycles [7]. As
part our ongoing research program aiming at the search of
bioactive quinolines, we used Schiff bases 1-4. These
azomethines were obtained by the reaction of quinoline-8-
carbaldehyde [8] with substituted aromatic amines such as
p-anisidine, p-toluidine, 2,4-dimethylaniline and
p-chloroaniline in refluxing dry ethanol or dry benzene.
The obtained aldimines 3 and 4 are new compounds.
The new 3-aryl-2-(8-quinolinyl)-4-thiazolidinones 5-12
were prepared by refluxing equimolar amounts of the
imines 1-4 and thioglycolic or thiolactic acids in dry ben-
zene in good yields (Scheme 1,Table 1).
the methyl protons and two quartets at δ 3.46-4.20 from a pro-
ton at C-5 due to stereoisomerism at the chiral carbon atom.
The ir spectra of the thiazolidinones 5-12, show the
characteristic C=O stretching appearing in the region of
-1
-1
1680-1660 cm . The strong sharp band at 1620-1610 cm
corresponding to the starting azomethines was absent,
which was the most characteristic evidence of the cyclo-
condensation.
There has been considerable recent interest in the study
of the addition of allylmetal compounds to aldimines to
give diverse homoallyllic amines with different hetero-
cyclic substituents. Thus, in continuation of our research
program [9-11], we performed the C-allylation reaction on
the Schiff bases 1-4. The treatment of the aldimines with
allylmagnesium bromide, prepared from magnesium and
1
The H nmr spectra of 5, 7, 9 and 11 displayed doublets at δ
3.44-4.06 due to the methylene protons H and H at C-5 in
A
B
1
addition to other signals. The H nmr spectra of the com-
pounds 6, 8 and 12 showed two doublets at δ 1.64-1.75 from

234
N. Öcal, Ç. Yolaçan, S¸. Kaban, L. Vargas M. and V. Kouznetsov
Vol. 38
allyl bromide in dry ether, gave the respective quinolines
13-16 (Scheme 2, Table 2). These quinolines are consid-
ered as versatile synthons for the construction of nitrogen
containing heterocycles.
elsewhere. Also, these quinolines could be used in the syn-
thesis of more complex structures such as the synthesis of
leukotriene D4 antagonist analogs; that at the moment is
one of our research programs.
EXPERIMENTAL
Melting points were uncorrected and measured in open cap-
illaries with an Electrothermal IA 9100 melting point apparatus.
The ir spectra were recorded on either a Philips PU 9714 (com-
pounds 1-12) or a Perkin Elmer 599B-FT (compounds 13-17)
spectrometer in potassium bromide pellets unless otherwise indi-
1
13
cated. The H and C nmr spectra were determined on either a
Varian 200 MHz Gemini (compounds 1-12) or a Jeol 400 MHz
spectrometer (compounds 13-17) in deuteriochloroform with
tetramethylsilane as internal standard. Data are reported as follows:
chemical shift (multiplicity, number of protons, coupling constants
and group). The ms spectra were obtained using a Shimadzu
GS/MS QP 2000 A. Elemental analyses were performed on a Leco
CHN-600 analyzer. Solvents and common reagents, obtained from
Merck and Aldrich, were reagent grade.
General Procedure for the Reaction of Quinoline-8-carbaldehyde
with Anilines.
Table 2
4-N-Arylamino-4-(8-quinolinyl)-1-butenes 13-16
To quinoline-8-carbaldehyde (1.7g, 10 mmoles) was added
p-chloroaniline or 2,4-dimethylaniline (10 mmoles) in dry ben-
zene (25 ml) with a small amount of potassium carbonate. The
reaction mixture was refluxed for 10 hours. The crystalline solid
separated at room temperature and was filtered and recrystallised
from ethanol.
Compound
X
Y
%
13
14
15
16
OCH
CH
CH
Cl
H
H
CH
H
83
87
94
96
3
3
3
3
8-[N-(2,4-Dimethylphenyl)iminomethyl]quinoline (3).
This compound was obtained in 73% yield, mp 94°; ir (potas-
sium bromide): ν =CH 3040, ν C=N 1610 cm ; H nmr (deuteri-
After a standard work-up, this reaction furnished hetero-
cyclic derivatives 13-16 as viscous oils in high yields. The
products obtained were purificated by means of a short
-1 1
ochloroform): δ 2.11 (s, 3H, CH ), 2.30 (s, 3H, CH ), 6.71-8.82
3
3
ppm (m, 10H, phenyl and quinoline protons and CH=N).
1
chromatographic column (alumina). In the H nmr spectra
8-[N-(4-Chlorophenyl)iminomethyl]quinoline (4).
of the quinolines 13-16, the protons of butene chain gave
rise very characteristic groups of signals. The doublet of
doublet from a proton at C-4 was observed at δ 2.05 ppm.
This compound was obtained in 70% yield, mp 118°; ir (potas-
-1 1
sium bromide): ν =CH 3040, ν C=N 1605 cm ; H nmr (deuterio-
chloroform): δ 7.26-9.93 ppm (m, 11H, phenyl and quinoline pro-
tons and CH=N).
The two multiplets from the 3-CH (H and H are
2
A
B
diastereotopic) appeared in the region δ 2.71-2.76 and
2.94-3.04 ppm, respectively. At low fields, the olefinic
protons exhibit multiplets between δ 5.09-5.20 and δ 5.50-
5.84 ppm. The ir spectra of the compounds prepared
showed a characteristic band of the amine group in the
General Procedure for Reaction of Aldimines 1-4 with Mercapto
Acids.
A mixture of the appropriate aldimine (1-4) (10 mmoles) and
thioglycolic acid or thiolactic acid (15 mmoles) in dry benzene
was refluxed on a water-bath for 15 hours, cooled and poured
into water. The organic layer was washed with potassium bicar-
bonate solution (30 ml, 10%) and then with water, dried with cal-
cium chloride and the benzene was distilled off. The residue gave
the appropriate quinoline on crystallization from petroleum ether
(40-60°)-EtOH (1:1).
-1
3429-3403 cm region.
The N-allylation of 14 with allyl bromide in the presence
of potassium carbonate in boiling acetone afforded deriva-
tive 17 in 72% yield. Its structure was established using ir
and nmr spectroscopy. As expected, in its ir spectrum, the
band corresponding to the amine group was missing. The
N-allylic protons were observed as multiplets at δ 3.92-
3-(4-Methoxyphenyl)-2-(8-quinolinyl)-4-thiazolidinone (5).
4.00, 5.00-5.10 and 5.90-5.94 ppm ( N-CH -CH=CH ).
2
2
This compound was obtained in 61% yield, mp 151°; ir (potas-
In summary, we have obtained a new series of poten-
tially bioactive C-8 substituted quinolines with thiazoli-
dine or aminobutene moieties. Their biological activities
are under investigation and the results will be published
-1
1
sium bromide): ν =CH 3060-2980, ν C=O 1665 cm ; H nmr
(deuteriochloroform): δ 3.69 (s, 3H, OCH ), 3.78-4.06 (d+d, 2H,
3
5-CH ; H and H ), 6.74-8.96 ppm (m, 11H, phenyl and quinoline
2
A
B
13
protons and 2-CH); C nmr (100 MHz): δ 173.8 (C=O), 116.2-

Jan-Feb 2001
Transformations of Schiff Bases Derived From Quinoline-8-carbaldehyde
235
159.8 (phenyl and quinoline carbons), 62.8 (OCH ), 57.3 (2-CH),
(deuteriochloroform): δ 3.78-4.05 (d+d, 2H, 5-CH ; H and H ),
2 A B
3
35.5 ppm (5-CH ); ms: m/z 336 (molecular ion).
7.17-8.98 ppm (m, 11H, phenyl and quinoline protons and
2-CH); ms: m/z 340 (molecular ion).
2
Anal.Calcd. for C H N O S: C, 67.85; H, 4.79; N, 8.32.
19 16
2 2
Found: C, 67.89; H, 4.81; N, 8.34.
Anal. Calcd. for C H ClN OS: C, 63.43; H, 3.84; N, 8.21.
18 13 2
Found: C, 63.40; H, 3.80; N, 8.26.
5-Methyl-3-(4-methoxyphenyl)-2-(8-quinolinyl)-4-thiazoli-
dinone (6).
5-Methyl-3-(4-chlorophenyl)-2-(8-quinolinyl)-4-thiazolidinone (12).
This compound was obtained in 57% yield, mp 157°; ir (potas-
This compound was obtained in 94% yield, mp 157°; ir (potas-
sium bromide): ν =CH 3040-2980, ν C=O 1665 cm ; H nmr
-1
1
-1 1
sium bromide): ν =CH 3060, ν C=O 1675 cm ; H nmr (deuterio-
(deuteriochloroform): δ 1.64-1.73 (dd, 6H, 5-CH ), 3.68-3.70 (s,
chloroform): δ 1.64-1.72 (d+d, 6H, CH ), 4.09-4.20 (q+q, 2H,
3
3
6H, OCH ), 4.13-4.20 (q+q, 2H, A and B, 5-CH), 6.73-8.96 ppm
(m, 22H, phenyl and quinoline protons and 2-CH); ms: m/z 350
(molecular ion).
5-CH), 7.14-8.98 ppm (m, 22H, phenyl and quinoline protons and
2-CH); C nmr (100 MHz): δ 176.0 (C=O), 122.1-150.0 (phenyl
and quinoline carbons), 60.3 (2-CH), 42.0 (5-CH), 20.0 ppm
3
13
Anal. Calcd. for C H N O S: C, 68.56; H, 5.18; N, 7.99.
(CH ); ms: m/z 354 (molecular ion).
20 18
2
2
3
Found: C, 68.58; H, 5.20; N, 7.93.
Anal. Calcd. for C H ClN OS: C, 64.31; H, 4.26; N, 7.89.
19 15 2
Found: C, 64.36; H, 4.22; N, 7.91.
3-(4-Methylphenyl)-2-(8-quinolinyl)-4-thiazolidinone (7).
This compound was obtained in 57% yield, mp 141°; ir (potas-
General Procedure for Reaction of Aldimines 1-4 with
Allylmagnesium Bromide.
-1
1
sium bromide): ν =CH 3040, ν C=O 1660 cm ; H NMR (deu-
teriochloroform): δ 2.23 (s, 3H, CH ), 3.77-4.05 (d +d, 2H,
The appropriate aldimine (1-4) (4.06 mmoles) in 40 ml of ether
was added slowly to 25 ml of on ether solution of allylmagne-
sium bromide prepared from 48.8 mmoles of magnesium and
32.5 mmoles of allyl bromide. The mixture was stirred for
4 hours at room temperature and then cooled and treated with sat-
urated ammonium chloride solution. The products were extracted
with ether (3 x 10 ml). The organic layer was dried (sodium sul-
fate) and the residue purified by chromatographic column (alu-
mina). The compounds 13-16 were obtained as brownish oils
except compound 15, which is a brown solid.
3
5-CH ; H and H ), 7.03-8.97 ppm (m, 11H, phenyl and quino-
2
A
B
line protons and 2-CH); ms: m/z 320 (molecular ion).
Anal. Calcd. for C H N OS: C, 71.24; H, 5.03; N, 8.74.
19 16
2
Found: C, 71.26; H, 4.99; N, 8.76.
5-Methyl-3-(4-methylphenyl)-2-(8-quinolinyl)-4-thiazolidinone (8).
This compound was obtained in 78% yield, mp 162°;
-1
ir (potassium bromide): ν =CH 3040, ν C=O 1665 cm ;
1
H nmr (deuteriochloroform): δ 1.60-1.72 (d+d, 6H, 5-CH ),
3
2.01-2.22 (d+d, 6H, CH ), 3.46-4.20 (q+q, 2H, A and B,
3
4-N-(4-Methoxyphenyl)amino-4-(8-quinolinyl)-1-butene (13).
This compound was obtained in 83% yield, oil; ir (neat): ν NH
5-CH), 7.00-8.96 ppm (m, 22H, phenyl and quinoline protons
13
and 2-CH); C nmr (100 MHz): δ 176.6 (C=O), 123.6-151.8
-1
1
3403, 1639, ν C=C 1599, 917 cm ; H nmr (deuteriochloro-
form): δ 2.08 (dd, J = 7 Hz, 1H, 4-H), 2.71, 2.95 (m, each, 1H,
3-CH ; H and H ), 3.66 (s, 3H, OCH ), 5.10-5.13 (m, 2H,
(phenyl and quinoline carbons), 59.8-60.2 (2-CH), 43.4-45.0
(5-CH), 22.88-23.28 (5-CH ), 19.81 ppm (CH ); ms: m/z 334
3
3
(molecular ion).
2
A
B
3
=CH ), 5.43-5.87 (m, 1H, -CH=), 6.58-6.64 (AA'BB'-system,
Anal. Calcd. for C H N OS: C, 71.80; H, 5.42; N, 8.38.
2
20 18
2
4H, phenyl protons), 6.97-8.02 ppm (m, 6H, quinoline protons);
C nmr (100 MHz): δ 118.6-154.7 (phenyl and quinoline car-
Found: C, 71.82; H, 5.40; N, 8.40.
13
3-(2,4-Dimethylphenyl)-2-(8-quinolinyl)-4-thiazolidinone (9).
This compound was obtained in 42% yield, mp 165°; ir (potas-
bons and =CH), 114.9 (=CH ); 55.7 (OCH ), 55.8 (4-CH), 41.7
2
3
ppm (3-CH ); ms: m/z 304 (molecular ion).
2
-1 1
sium bromide): ν =CH 3040, ν C=O 1670 cm ; H nmr (deuterio-
Anal. Calcd. for C H N O: C, 78.95; H, 6.58; N, 9.21.
20 20 2
chloroform): δ 2.20 (s, 3H, CH ), 2.36 (s, 3H, CH ), 3.44-3.90
Found: C, 78.90; H, 6.68; N, 9.25.
3
3
(d+d, 2H, 5-CH ; H and H ), 6.70-8.92 ppm (m, 10H, phenyl
and quinoline protons and 2-CH); ms: m/z 334 (molecular ion).
2
A
B
4-N-(4-Methylphenyl)amino-4-(8-quinolinyl)-1-butene (14).
This compound was obtained in 87% yield, oil; ir (neat): ν NH
Anal. Calcd. for C H N OS: C, 71.80; H, 5.42; N, 8.38.
20 18
2
-1
1
3412, 1639, ν C=C 1599, 916 cm ; H nmr (deuteriochloro-
form): δ 2.06 (dd, J = 7 Hz, 1H, 4-H), 2.18 (s, 3H, CH ), 2.77,
Found: C, 71.83; H, 5.44; N, 8.34.
3
5-Methyl-3-(2,4-dimethylphenyl)-2-(8-quinolinyl)-4-thiazolidi-
none (10).
2.98 (m, each, 1H, 3-CH ; H and H ), 5.11-5.21 (m, 2H,
2
A
B
=CH ), 5.56-5.86 (m, 1H, -CH=), 6.51-6.87 (AA'BB'-system,
2
4H, phenyl protons), 6.97-8.05 ppm (m, 6H, quinoline protons);
C nmr (100 MHz): δ 118.9-155.1 (phenyl and quinoline car-
This compound was obtained in 32% yield, mp 168°; ir
(potassium bromide): ν =CH 3040, ν C=O 1665 cm ; H nmr
13
-1
1
bons and =CH), 113.9 (=CH ), 54.9 (4-CH), 41.6 (5-CH ), 20.5
(deuteriochloroform): δ 1.76-1.79 (d, 3H, 5-CH ), 2.14 (s, 3H,
2
2
3
ppm (CH ); ms: m/z 288 (molecular ion).
CH ), 2.33 (s, 3H, CH ), 4.13-4.23 (q, 1H, 5-CH), 6.72-8.85
3
3
3
ppm (m, 10H, phenyl and quinoline protons and 2-CH); ms: m/z
348 (molecular ion).
Anal. Calcd. for C H N : C, 83.33; H, 6.94; N, 9.72. Found:
C, 83.15; H, 7.23; N, 9.83.
20 20 2
Anal. Calcd. for C H N OS: C, 72.40; H, 5.78; N, 8.04.
Found: C, 72.45; H, 5.75; N, 8.01.
21 20
2
4-N-(2,4-Dimethylphenyl)amino-4-(8-quinolinyl)-1-butene (15).
This compound was obtained in 94% yield, mp 66-68º (heptane);
ir (potassium bromide): ν NH 3429, 1639, ν C=C 1599, 916 cm ;
H nmr (deuteriochloroform): δ 2.05 (dd, J = 7 Hz, 1H, 4-H), 2.18,
3-(4-Chlorophenyl)-2-(8-quinolinyl)-4-thiazolidinone (11).
This compound was obtained in 62% yield, mp 181°; ir (potas-
-1
1
-1
1
2.24 (s, each, 3H, CH ), 2.77, 3.04 (m, each, 1H, 3-CH ; H and
sium bromide): ν =CH 3060, ν C=O 1680 cm ; H nmr
3
2
A

236
N. Öcal, Ç. Yolaçan, S¸. Kaban, L. Vargas M. and V. Kouznetsov
Vol. 38
H ), 5.11-5.25 (m, 2H, =CH ), 5.50-5.91 (m, 1H, -CH=), 6.25-8.05
ppm (m, 10H, phenyl and quinoline protons); C nmr (100 MHz):
Anal. Calcd. for C H N : C, 84.15; H, 7.32; N, 8.54. Found:
23 24 2
C, 84.10; H, 7.30; N, 8.49.
B
2
13
δ 118.9-155.2 (phenyl and quinoline carbons and =CH), 113.8
Acknowledgements.
(=CH ), 53.9 (4-CH), 41.8 (3-CH ), 18.7 ppm (CH ); ms: m/z 302
2
2
3
(molecular ion).
Some financial support of this research by the Research
Foundation of Yildiz Technical University (project number: 94-
B-01-02-02) is gratefully acknowledgement. VK and LV thank to
Colciencias (Grant No.115-05-353-96) for the financial support
and to Dr. Leticia Quintero and Miss Sara Montiel (Universidad
Autonoma de Puebla, Mexico) for the NMR measurements.
Anal. Calcd. for C H N : C, 83.44; H, 7.28; N, 9.27. Found:
C, 83.48; H, 7.30; N, 9.20.
21 22
2
4-N-(4-Chlorophenyl)amino-4-(8-quinolinyl)-1-butene (16).
This compound was obtained in 96% yield, oil; ir (neat): ν NH
3415, 1639, ν C=C 1599, 918 cm ; H nmr (deuteriochloro-
form): δ 2.05 (dd, J = 7 Hz, 1H, 4-H), 2.76, 2.94 (m, each, 1H, 3-
-1
1
REFERENCES AND NOTES
CH ; H and H ), 5.09-5.20 (m, 2H, =CH ), 5.52-5.84 (m, 1H, -
2
A
B
2
CH=), 6.48-6.97 (AA'BB'-system, 4H, phenyl protons), 6.94-
8.05 ppm (m, 6H, quinoline protons); C nmr (100 MHz): δ
118.9-154.9 (phenyl and quinoline carbons and =CH), 114.8
13
[*] Fax 5776-346149 or 90212- 2245013. E-mail:
kouznet@uis.edu.co or nocal@yildiz.edu.tr
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(=CH ), 54.2 (4-CH), 41.5 ppm (3-CH ); ms: m/z 308 (molecular
2
2
35
ion for Cl).
Anal. Calcd. for C H N Cl: C, 73.91; H, 5.51; N, 9.07.
19 17
2
Found: C, 73.88; H, 5.81; N, 9.21.
4-[N-Allyl, N-(4-methylphenyl)]amino-4-(8-quinolinyl)-1-
butene (17).
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A suspension of 14 (0.38 g, 1.31 mmoles) in 10 ml acetone
with allyl bromide (1.58 g, 13.10 mmoles) and potassium carbon-
ate (0.90 g, 6.50 mmoles) was allowed to reflux for 4 days. The
reaction was monitored by tlc. The mixture was treated with
water. The products were extracted and the organic layer was
dried (sodium sulfate) and the residue purified by a short chro-
matographic column (alumina). The N-allylderivative 17 was
obtained 0.34 g (78%) as brownish oil; ir (neat): ν C=C 1600,
-1 1
914 cm ; H nmr (deuteriochloroform): δ 1.92 (dd, J = 7 Hz, 1H,
4-H), 2.26 (s, 3H, CH ), 2.98 (m, 2H, 3-CH ), 3.97 (m, 2H, N-
3
2
CH ), 4.96-5.20 (m, 4H, =CH ), 5.57-6.00 (m, 2H, -CH=), 6.67-
2
2
7.03 (AA'BB'-system, 4H, phenyl protons), 7.00-8.01 ppm (m,
6H, quinoline protons); ms: m/z 328 (molecular ion).