Vanilline alkanoates in the synthesis of hexahydrobenzacridine and octahydroxanthene derivatives

Article abstract of DOI:10.1007/s11176-005-0282-2

Cascade heterocyclization of 1,3-cyclohexanedione and dimedone with 2-naphthylamine and vanilline esters gave derivatives of 2-methoxy-4-(alkyl-11- oxo-7,8,9,10,11,12-hexahydrobenz[a]acridin-12-yl)- and 2-methoxy-4-(alkyl-1,8- dioxo-2,3,4,5,6,7,8,9-octahydro-1H-xanthen-9-yl)phenyl esters of aliphatic (C₁- C₄ ) carboxylic acids. 2005 Pleiades Publishing, Inc.

Full text of DOI:10.1007/s11176-005-0282-2

Russian Journal of General Chemistry, Vol. 75, No. 4, 2005, pp. 617 621. Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 4, 2005,
pp. 654 658.
Original Russian Text Copyright
2005 by Kozlov, Basalaeva.
Vanilline Alkanoates in the Synthesis
of Hexahydrobenzacridine and Octahydroxanthene Derivatives
N. G. Kozlov and L. I. Basalaeva
Institute of Physical Organic Chemistry, National Academy Sciences of Belarus, Minsk, Belarus
Received November 14, 2003
Abstract Cascade heterocyclization of 1,3-cyclohexanedione and dimedone with 2-naphthylamine and
vanilline esters gave derivatives of 2-methoxy-4-(alkyl-11-oxo-7,8,9,10,11,12-hexahydrobenz[a]acridin-12-yl)-
and 2-methoxy-4-(alkyl-1,8-dioxo-2,3,4,5,6,7,8,9-octahydro-1H-xanthen-9-yl)phenyl esters of aliphatic
(C1 C4) carboxylic acids.
Introduction of natural fragments, such as esters
derived from plant phenols, into benzacridines,
analogs of natural alkaloids, is a promising synthetic
approach to novel biologically active substances.
Moreover, acridine derivatives have been used to
synthesize labeled conjugates with medicinals,
peptides, proteins, and nucleic acids [1 3], that
exhibit antitumor and DNA-binding properties.
oxo-2,3,4,5,6,7,8,9-octahydro-1H-xanthen-9-yl)- or
4-(3,3,6,6-tetramethyl-1,8-dioxo-2,3,4,5,6,7,8,9-octa-
hydro-1H-xanthen-9-yl)carboxylates VIa VIe and
VIIa VIIe and the reaction with 2-naphthylamine pro-
vides benz[a]acridines IVa IVe and Va Ve. Octa-
hydro-1H-xanthen-9-yl derivatives VIa VIe and
VIIa VIIe that form as by-products in the above re-
action were also obtained by refluxing in ethanol of a
double excess of diketone Ia or Ib with aldehydes
IIIa IIIe (Tables 1 and 2).
In the present work we have studied reactions of
1,3-cyclohexadienone (Ia) and 5,5-dimethyl-1,3-cyclo-
hexadione (dimedone) (Ib) with 2-naphthylamine (II)
and vanillin esters IIIa IIIe. The reactions were per-
formed in ethanol under reflux. At equimolar reagent
ratios, 2-methoxy-4-(11-oxo-7,8,9,10,11,12-hexahyd-
robenz[a]acridin-12-yl)phenyl carboxylates IVa IVe
(with dione Ia) and 2-methoxy-4-(9,9-dimethyl-11-
oxo-7,8,9,10,11,12-hexahydrobenz[a]acridin-12-yl)-
phenyl carboxylates Va Ve (with dione Ib) were
synthezized.
1
The H NMR spectra of benz[a]acridines IVa IVe
and Va Ve correspond, in position and multiplicity of
aromatic proton signals, to the benz[a]acridine struc-
ture [4]. The H12 methine proton of the dihydropyri-
dine ring gives a singlet at 5.88 5.94 ppm. This signal
is shifted downfield compared with respective methine
proton signals of cyclic compounds [5], which is ex-
plained by the anisotropic effect of the neighboring
1
aromatic ring (Table 2). The H NMR spectra of octa-
hydro-1H-xanthen-9-yl derivatives VIa VIe and
VIIa VIIe (Table 2) are fully supportive of the struc-
ture of these compounds.
In the three-component mixture I II III, where
each of the reagents can react with the other two,
preferred are the reactions Ia (or Ib)+II
A and Ia
(or Ib) + IIIa IIIe B. The reactions of enamine A
The IR spectra of benz[a]acridines IVa IVe and
Va Ve display characteristic stretching and deforma-
tion NH vibration bands at 3300 and 1655 1650 cm ,
with aldehydes IIIa IIIe and of dione B with 2-
naphthylamine (II) provide intermediate C whose
dehydration gives rise to benz[a]acridin-11-ones IVa
IVe and Va Ve. The reactions involve formation of a
1,4-dihydropyridine ring that is likely to have an axial
aryl substituent and thus acoplanar to the main ring.
1
respectively. In the IR spectra of benz[a]acridines
IVa IVe and Va Ve and octahydro-1H-xanthen-9-yl
derivatives VIa VIe, stretching vibrations of the
carbonyl group conjugated with the enamine fragment
1
appear at 1615 1610 cm . The ester carbonyl gives a
Fuzed benz[a]acrydine derivatives IVa IVe and
Va Ve are colorless or light yellow crystals (Tables 1
and 2).
1
strong absorption band at 1640 1630 cm . This band
is shifted red, which is probably associated with the
involvement of the alkoxycarbonyl, amino, and eno-
lized ketone carbonyl groups in intermolecular hydro-
gen bonding. The C O C fragments absorb at 1240
Along with compounds IVa IVe and Va Ve, the
reactions gives rise to arylmethylene bisdiketones D
whose dehydration yields 2-methoxyphenyl 4-(1,8-di-
1
1220 cm . Stretching vibrations of alkyl and cyclo-
1070-3632/05/7504-0617 2005 Pleiades Publishing, Inc.

618
KOZLOV, BASALAEVA
O
R
+
R
O
R
O
R
O
O
O
R
R
R
R
O
NH
O
O
IIIa IIIe
IIIa IIIe
O
O
Ia, Ib
A
OH
H2N
R
R
II
NH
II
O
O
C
HO
O
O
R
O
B
R
R
R
R
OH HN
OH HO
R
R
R
R
R
10
11
O
O
R
O
9R
8
O
O
12
O
O
O
II
1
NH
O
2
3
O
R
O
O
6
R
O
O
4
5
II
E
IVa IVe, Va Ve
D
R
R
4
5
O
O
6 R
R3
2
7
1O
O
8
O
R
O
VIa VIe, VIIa VIIe
I, R = H (a), CH3 (b); III, R = CH3 (a), C2H5 (b), C3H7 (c), iso-C3H7 (d), C4H9 (e); IV, VI, R = H, R = CH3 (a), C2H5
(b), C3H7 (c), iso-C3H7 (d), C4H9 (e); V, R = CH3, R = CH3 (a), C2H5 (b), C3H7 (c), iso-C3H7 (d), C4H9 (e); VII, R =
CH3, R = CH3 (a), C2H5 (b), C3H7 (c), iso-C3H7 (d), C4H9 (e).
1
aliphatic CH bonds appear at 2960 2840 cm and of
aromatic CH bonds, at 3130 3030 cm .
(I 11 18%). The base peak in the spectra belongs to
an [M MeO R COOC6H3] ion. The spectra of
1
benz[a]acridines IVa IVe and Va Ve all show an
m/z 192 ion peak (15 38%) formed by elimination
The mass spectra of compounds IVa IVe, Va Ve,
VIa VIe, and VIIa VIIe contain molecular ion peaks
from the [M
MeO
R COOC6H3]+ ion of
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 75 No. 4 2005

VANILLINE ALKANOATES IN THE SYNTHESIS
619
Table 1. Yields, melting points, and elemental analyses of 4-(11-oxo-7,8,9,10,11,12-hexahydrobenz[a]acridin-12-yl)-
(IVa IVe)-, 4-(9,9-dimethyl-11-oxo-7,8,9,10,11,12-hexahydrobenz[a]acridin-12-yl)-(Va Ve)-, 4-(1,8-dioxo-2,3,4,5,6,7,-
8,9-octahydro-1H-xanthen-9-yl)-(VIa VIe)-, and 4-(3,3,6,6-tetramethyl-1,8-dioxo-2,3,4,5,6,7,8,9-octahydro-1H-xanthen-
9-yl)- (VIIa VIIe)-2-methoxyphenyl esters of aliphatic (C1 C4) carboxylic acids
Found, %
H
Calculated, %
H
Comp. no. Yield, %
mp, Ca
Formula
C
N
C
N
IVa
IVb
IVc
IVd
IVe
Va
Vb
Vc
Vd
Ve
VIa
VIb
VIc
VId
VIe
VIIa
VIIb
VIIc
VIId
VIIe
75
59
46
43
70
94
96
95
77
92
43
46
22
15
19
58
31
36
45
29
298
270
258 260
302 304
256
292
252 254
256
248 250
234
176 177
141 142
182
75.63
75.90
76.14
76.21
76.49
76.22
76.51
76.80
76.78
77.00
69.10
69.68
70.22
70.19
70.73
71.21
71.65
72.13
72.08
72.48
5.56
5.82
6.14
6.10
6.38
6.15
6.42
6.63
6.59
6.85
5.74
6.03
6.35
6.35
6.60
6.85
7.10
7.28
7.32
7.53
3.37
3.29
3.19
3.17
3.10
3.20
3.11
3.01
2.97
2.91
C26H23NO4
C27H25NO4
C28H27NO4
C28H27NO4
C29H29NO4
C28H27NO4
C29H29NO4
C30H31NO4
C30H31NO4
C31H33NO4
C22H22O6
C23H24O6
C24H26O6
C24H26O6
C25H28O6
C26H30O6
C27H32O6
C28H34O6
C28H34O6
C29H36O6
75.55
75.88
76.19
76.19
76.48
76.19
76.48
76.76
76.76
77.02
69.11
69.70
70.24
70.24
70.75
71.23
71.68
72.10
72.10
72.50
5.57
5.85
6.12
6.12
6.37
6.12
6.37
6.61
6.61
6.83
5.76
6.06
6.34
6.34
6.60
6.84
7.08
7.30
7.30
7.50
3.39
3.28
3.17
3.17
3.07
3.17
3.07
2.98
2.98
2.90
179
184 185
141 142
167 168
156 158
150
139
CH2CH2CO (IVa IVe) or (CH3)2CCH2CO (Va Ve)
fragments. The mass spectra of octahydro-1H-xan-
then-9-yl derivatives VIa VIe and VIIa VIIe lack
such peaks.
the residue. The reaction mixture was refluxed for 1 h,
CH2Cl2 was removed, and the residue was dissolved
in 500 ml of benzene. The solution was washed with
three portions of water, three portions of 5% aqueous
NaHCO3, and dried with CaCl2. The solvent was re-
moved, and the residue was distilled in a vacuum or
recrystallized from a 1:1 benzene hexane mixture.
EXPERIMENTAL
The mass spectra were measured on a Finnigan-
MAT Incos-50 instrument, ionizing energy 70 eV.
The IR spectra were obtained on a Nicolet Protege-
Compound IIIa, yield 92%, mp 78 79 C (pub-
lished data [6]: mp 77 79 C). H NMR spectrum, ,
ppm: 2.32 s (Me), 3.92 s (OMe), 7.18 d, 7.48 m (3H,
Harom), 9.92 s (CH).
Compound IIIb, yield 79%, mp 33 34 C. 1H
NMR spectrum, , ppm: 1.25 t (Me), 2.52 q (CH2),
3.84 s (OMe), 7.13 d, 7.42 m (3H, Harom), 9.88 s
(CH). Found, %: C 63.29; H 5.73. C11H12O4. Calcu-
lated, %: C 63.46; H 5.77.
1
1
460 Fourier spectrometer. The H NMR spectra were
taken on Bruker AC-500 (500 MHz) and Tesla BS-567
(100 MHz) spectrometers in DMSO-d6, internal
reference TMS.
The melting points were measured in a Kofler hot
stage.
Vanillin alkanoates IIIa IIIe. To a solution of
0.2 mol of vanillin in 500 ml of absolute CH2Cl2,
absolute pyridine, 0.25 mol, and, in small portions
with stirring, 0.2 mol of acid chloride prepared by 6-h
refluxing of a mixture of 1 mol of carboxylic acid,
1.3 mol of SOCl2, and 500 ml of absolute benzene,
followed by removal of the solvent and distillation of
Compound IIIc, yield 81%, bp 137 138 C
(0.5 mm Hg), n2D0 1.5281. H NMR spectrum, , ppm:
1
1.02 t (Me), 1.63 m (CH2), 2.51 t (CH2), 3.84 s (OMe),
7.15 d, 7.40 m (3H, Harom), 9.90 s (CH). Found, %: C
64.71; H 6.32. C12H14O4. Calculated, %: C 64.86;
H 6.31.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 75 No. 4 2005

620
KOZLOV, BASALAEVA
Table 2. 1H NMR spectra of compounds IVa IVd VIIa VIIe, , ppm (J, Hz)
OMe, s CH, s Cycloaliphatic, R, and NH protons
Aromatic and R protons
IVa 3.69
5.88
5.90
1.90 2.00 m, 2.20 2.30 m, 2.60 2.65 m, 6.55 d (8.0), 6.73 d (8.2), 7.13 s, 7.29 7.34 m, 7.43 t,
9.70 s (NH) 7.73 7.80 m, 7.95 d (7.6), 2.15 s (3H, CH3)
1.90 2.00 m, 2.10 2.15 m, 2.60 2.65 m, 6.49 d (7.8), 6.62 d (8.0), 7.08 s, 7.24 7.30 m, 7.38 t,
IVb 3.72
IVc 3.75
9.50 s (NH)
7.68 d (8.8), 7.71 d (8.6), 7.79 d (7.0), 1.19 t (3H,
CH2CH3), 1.26 q (2H, CH2CH3)
1.90 2.10 m, 2.20 2.28 m, 2.50 2.58 m, 6.48 d (8.0), 6.65 d (8.7), 7.14 s, 7.22 7.30 m, 7.35
5.90
9.48 s (NH)
7.40 m, 7.68 d (6.9), 7.73 d (7.2), 7.95 d (7.5), 1.00 t
(3H, CH2CH2CH3), 1.70 m (2H, CH2CH2CH3),
2.65 m (2H, CH2CH2CH3)
IVd 3.74
IVe 3.76
5.79
5.94
1.87 1.98 m, 2.15 2.28 m, 2.58 2.63 m, 6.47 d (8.6), 6.70 d (8.8), 7.16 s, 7.20 7.40 m, 7.70 d
9.63 s (NH)
(7.6), 7.90 d (7.3), 1.35 d (7.0) [6H, CH(CH3)2],
2.88 m [H, CH(CH3)2]
1.98 2.09 m, 2.20 2.30 m, 2.59 2.64 m, 6.50 d (8.3), 6.64 d (8.9), 7.10 s, 7.20 7.30 m, 7.35
9.49 s (NH)
7.40 m, 7.68 7.75 m, 7.90 d (6.8), 0.96 t (3H,
CH2CH2CH2CH3), 1.43 m (2H, CH2CH2CH2CH3),
1.65 m (2H, CH2CH2CH2CH3), 2.45
CH2CH2CH2CH3)
t (2H,
Va
Vb
3.74
3.70
5.87
5.89
2.15 2.20 m, 2.30 2.49 m, 9.37 s (NH), 6.80 d (8.4), 7.12 d (8.3), 7.18 s, 7.28 7.34 m, 7.40 t,
0.95 s (3H, CH3), 1.10 s (3H, CH3) 7.60 d (7.8), 7.90 d (7.9), 2.10 s (3H, CH3)
2.10 2.123 m, 2.30 2.35 m, 9.37 s (NH), 7.00 d (7.9), 7.14 d (7.3), 7.10 s, 7.30 7.35 m, 7.37 t,
0.95 s (3H, CH3), 1.10 s (3H, CH3)
7.68 d (6.7), 7.75 d (7.4), 7.95 d (6.9), 1.17 t (3H,
CH3) 2.50 q (2H, CH2CH3)
Vc
Vd
Ve
3.76
3.69
3.72
5.88
5.82
5.89
2.10 2.20 m, 2.25 2.40 m, 9.55 s (NH), 6.60 6.80 m, 7.10 7.30 m, 7.60 7.80 m, 7.90 8.10 m,
0.98 s (1H, CH3), 1.10 s (1H, CH3)
1.15 s (3H, CH2CH2CH3), 1.76 q (2H, CH2CH2CH3),
2.50 m (2H, CH2CH2CH3)
2.03 2.09 m, 2.10 2.13 m, 9.58 s (NH), 6.55 d (8.1), 6.60 d (7.3), 7.10 s, 7.29 7.34 m, 7.45
0.90 s (3H, CH3), 1.08 s (3H, CH3)
7.49 m, 7.72 7.80 m, 7.90 d (6.8), 1.20 d (6.5) [6H,
CH(CH3)2], 2.90 m [1H, CH(CH3)2]
2.15 2.20 m, 2.30 2.35 m, 9.35 s (NH), 6.52 d (6.5), 6.64 d (7.2), 7.10 s, 7.20 7.30 m, 7.35
0.90 s (3H, CH3), 1.10 s (3H, CH3)
7.40 m, 7.65 d (6.9), 7.08 d (7.5), 7.90 d (8.3), 0.90 t
(3H, CH2CH2CH2CH3), 1.40 m (2H, CH2CH2CH2
CH3), 1.60 m (2H, CH2CH2CH2CH3), 2.45 m (2H,
CH2CH2CH2CH3)
VIa 3.80
VIb 3.82
4.65
4.64
1.90 2.10 m, 2.24 s, 2.25 2.40 m
1.90 2.10 m, 2.25 2.30 m, 2.65 2.76 m 2.65 2.70 m 6.65 d (9.1), 6.79 d (8.3), 7.00 s, 1.20 t
6.85 d (8.9), 6.75 d (8.0), 7.00 s, 2.20 s (3H, CH3)
(3H, CH2CH3), 2.50 q (2H, CH2CH3)
VIc 3.80
4.63
1.95 2.10 m, 2.26 2.40 m, 2.65 2.7 m 6.67 d (8.6), 6.78 d (8.0), 6.69 s, 1.10 t (3H, CH2
CH2CH3), 1.75 m (2H, CH2CH2CH3), 2.45 m (2H,
CH2CH2CH3)
VId 3.75
VIe 3.80
4.67
4.64
1.90 2.15 m, 2.28 2.40 m, 2.60 2.75 m 6.68 d (8.4), 6.70 d (7.6), 6.70 s, 1.25 d (6.4) [6H,
CH(CH3)2], 2.85 m [1H, CH(CH3)2]
1.90 2.10 m, 2.30 2.40 m, 2.65 2.70 m 6.65 d (9.0), 6.80 d (7.8), 6.97 s, 0.90 t (3H,
CH2CH2CH2CH3), 1.48 m (2H, CH2CH2CH2CH3),
1.65 m (2H, CH2CH2CH2CH3), 2.50 m (2H, CH2
CH2CH2CH3)
VIIa 3.76
4.70
2.10 2.20 m, 2.35 2.50 m, 0.90 s (6H, 6.80 d (9.3), 6.85 s, 7.15 d (7.9), 1.25 s (3H, CH3)
2CH3), 1.10 s (6H, 2CH3)
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 75 No. 4 2005

VANILLINE ALKANOATES IN THE SYNTHESIS
621
Table 2. (Contd.)
OMe, s CH, s Cycloaliphatic, R, and NH protons
Aromatic and R protons
VIIb 3.80
VIIc 3.70
4.72
2.15 2.20 m, 2.40 2.60 m, 1.00 s (6H, 6.75 d (8.3), 6.80 s, 7.10 d (7.2), 1.22 t (3H, CH2
2CH3), 1.08 s (6H, 2CH3) CH3, 2.40 q (2H, CH2CH3)
2.20 2.50 m, 1.00 s (6H, 2CH3), 1.20 s 6.77 d (8.5), 6.79 d (6.5), 6.90 s, 1.10 t (3H, CH2
4.68
(6H, 2CH3)
CH2CH3), 1.75 q (2H, CH2CH2CH3), 2.45 m (2H,
CH2CH2CH3)
VIId 3.73
VIIe 3.80
4.55
4.59
2.10 2.19 m, 0.90 s (6H, 2CH3), 1.10 s 6.70 d (8.4), 6.85 6.92 m, 1.25 d [6H, CH(CH3)2],
(6H, 2CH3) 2.70 m [1H, CH(CH3)2]
2.15 2.20 m, 1.00 s (6H, 2CH3), 1.10 s 6.65 d (7.2), 6.80 d (6.2), 6.94 s, 0.95 t (3H,
(6H, 2CH3)
CH2CH2CH2CH3), 1.40 m (2H, CH2CH2CH2CH3),
1.65 m (2H, CH2CH2CH2CH3), 2.59 m (2H, CH2
CH2CH2CH3)
Compound IIId, yield 89%, mp 29 30 C. 1H
NMR spectrum, , ppm: 1.35 d, 2.88 m (7H, i-Pr),
3.90 s (OMe), 7.21 d, 7.50 m (3H, Harom), 9.96 s
(CH). Found, %: C 64.72; H 6.19. C12H14O4. Calcu-
lated, %: C 64.86; H 6.31.
(VIIa VIIe) of aliphatic (C1 C4) carboxylic acids.
To a solution of 0.01 mol of vanillin alkanoate IIIa
IIIe in 50 ml of ethanol, 0.02 mol of 1,3-cyclohexane-
dione (Ia) or dimedone (Ib) was added, and the mix-
ture was refluxed for 2 6 h. Crystals formed and were
separated, washed with diethyl ether, dried, and re-
crystallized from methanol.
Compound IIIe, yield 76%, bp 149 150 C
1
(0.5 mm Hg), n2D0 1.5273. H NMR spectrum, , ppm:
0.96 t (Me), 1.20 1.90 m (2CH2), 2.62 t (CH2), 3.96 s
(OMe), 7.15 d, 7.38 m (3H, Harom), 9.90 s (CH).
Found, %: C 66.01; H 6.62. C13H16O4. Calculated,
%: C 66.10; H 6.77.
ACKNOWLEDGMENTS
The work was financially supported by the Bela-
russian Republican Foundation for Basic Research
(grant no. X03-079).
2-Methoxy-4-(11-oxo-7,8,9,10,11,12-hexahydro-
benz[a]acridin-12-yl)phenyl esters IVa IVe of ali-
phatic (C1 C4) carboxylic acids. To a solution of
0.01 mol of 2-naphthylamine (II) in 50 ml of ethanol,
0.01 mol of vanillin alkanoate IIIa IIIe and 0.01 mol
of 1,3-cyclohexanedione (Ia) were added, and the
mixture was refluxed for 1 3 h (depending on the
radical chain length in the vanillin ester). After
cooling, crystal formed and were separated, washed
with hotmethanol, and recrystallized from benzene.
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12-hexahydrobenz[a]acridin-12-yl)phenyl esters
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tsionnoi spektroskopii organicheskikh soedinenii,
Moscow: Khimiya, 1970, p. 100.
2-Methoxy-4-(1,8-dioxo-2,3,4,5,6,7,8,9-octahyd-
ro-1H-xanthen-9-yl)- (VIa VIe)- and 2-methoxy-4-
(3,3,6,6-tetramethyl-1,8-dioxo-2,3,4,5,6,7,8,9-octa-
xydro-1H-xanthen-9-yl)-2-methoxyphenyl esters
6. Beilstein, vol. H8, p. 258.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 75 No. 4 2005