Synthesis, reactions, and anti-arrhythmic activity of substituted heterocyclic systems using 5-chloroanisic acid as starting material

Article abstract of DOI:10.1007/s00706-007-0701-7

A series of substituted heterocyclic systems were prepared from N1-[4-(4-fluorocinnamoyl)phenyl]-5-chloro-2-methoxybenzamide, which was prepared from the corresponding 5-chloroanisic acid (2-methoxy-4-chlorobenzoic acid) as starting material. Treating of the cinnamoyl derivative with hydrazine hydrate in dioxane afforded a pyrazoline, which was reacted with morpholine and paraformaldehyde to give the N-substituted pyrazoline. Acylation of pyrazoline with acetyl chloride in dioxane afforded the N-acetyl analogue. Also, the cinamoyl derivative was reacted with methylhydrazine, phenylhydrazine, or ethyl cyanoacetate to yield the corresponding N-methyl-, N-phenylpyrazoline, pyrane, and pyridone derivatives. Condensation of the cinnamoyl derivative with cyanothioacetamide gave the pyridinethione derivative, which was treated with ethyl chloroacetate affording the ethyl carboxylate derivative. Also, it was reacted with malononitrile or ethyl acetoacetae to give the cyano amino analougues and ethyl carboxylate, which was reacted with methylhydrazine to give the (indazolyl)phenyl derivative. On the other hand, reaction of cinnamoyl derivative with acetyl acetone afforded the cyclohexenyl derivative, which was reacted with hydrazine hydrate to give the [methylindazolyl]phenyl derivative. Condensation of the cinnamoyl derivative with guanidine hydrochloride or thiourea afforded the aminopyrimidine derivative and thioxopyrimidine. The latter was condensed with chloroacetic acid to yield a thiazolopyrimidine, which was condensed with 2-thiophenealdehyde to yield the arylmethylene derivative, however, it was also prepared directly from thiopyrimidine by the action of chloroacetic acid, 2-thiophenealdehyde, and anhydrous sodium acetate. The pharmacological screening showed that many of these compounds have good anti-arrhythmic activity and low toxicity.

Full text of DOI:10.1007/s00706-007-0701-7

Monatshefte fu¨r Chemie 138, 1019–1027 (2007)
DOI 10.1007/s00706-007-0701-7
Printed in The Netherlands
Synthesis, Reactions, and Anti-arrhythmic activity of Substituted
Heterocyclic Systems Using 5-Chloroanisic Acid as Starting Material
Ahmed F. A. Shalaby1, Mohamed M. Abdulla2;ꢀ, Abd El Galil E. Amr3, and Azza A. Hussain1
1
Chemistry Department, Faculty of Science, Cairo University, Cairo, Egypt
2
Research Units, Hi-Care Pharmaceutical Co., Cairo, Egypt
3
National Research Center, Applied Organic Chemistry Department, Dokki, Cairo, Egypt
Received April 2, 2007; accepted (revised) April 20, 2007; published online July 13, 2007
# Springer-Verlag 2007
Summary. A series of substituted heterocyclic systems
were prepared from N1-[4-(4-fluorocinnamoyl)phenyl]-5-
chloro-2-methoxybenzamide, which was prepared from the
corresponding 5-chloroanisic acid (2-methoxy-4-chloroben-
zoic acid) as starting material. Treating of the cinnamoyl
derivative with hydrazine hydrate in dioxane afforded a
pyrazoline, which was reacted with morpholine and para-
formaldehyde to give the N-substituted pyrazoline. Acyla-
tion of pyrazoline with acetyl chloride in dioxane afforded
the N-acetyl analogue. Also, the cinamoyl derivative was
reacted with methylhydrazine, phenylhydrazine, or ethyl
cyanoacetate to yield the corresponding N-methyl-, N-phe-
nylpyrazoline, pyrane, and pyridone derivatives. Condensa-
tion of the cinnamoyl derivative with cyanothioacetamide
gave the pyridinethione derivative, which was treated with
ethyl chloroacetate affording the ethyl carboxylate de-
rivative. Also, it was reacted with malononitrile or ethyl
acetoacetae to give the cyano amino analougues and ethyl
carboxylate, which was reacted with methylhydrazine to
give the (indazolyl)phenyl derivative. On the other hand,
reaction of cinnamoyl derivative with acetyl acetone af-
forded the cyclohexenyl derivative, which was reacted with
hydrazine hydrate to give the [methylindazolyl]phenyl de-
rivative. Condensation of the cinnamoyl derivative with
guanidine hydrochloride or thiourea afforded the amino-
pyrimidine derivative and thioxopyrimidine. The latter was
condensed with chloroacetic acid to yield a thiazolopyrimi-
dine, which was condensed with 2-thiophenealdehyde to
yield the arylmethylene derivative, however, it was also pre-
pared directly from thiopyrimidine by the action of chloro-
acetic acid, 2-thiophenealdehyde, and anhydrous sodium
acetate. The pharmacological screening showed that many
of these compounds have good anti-arrhythmic activity and
low toxicity.
Keywords. 5-Chloroanisic acid; 4-Fluorobenzaldehyde;
Thioxopyrimidine; Thiazolopyrimidine; Anti-arrhythmic
activity.
Introduction
In previous work we have reported on the sub-
stituted heterocyclic derivatives as analgesic, anti-
convulsant, and antiandrogenic agents [1–4] and
demonstrated their antimicrobial activity [5–8]. On
the other hand, cyanopyridone and cyanopyridine
derivatives are promising antimicrobial agents [9,
10] and display anticancer activities [11–15]. Some
of the chiral heterocyclic compounds containing a
pyridine moiety have been reported as anticancer
and anti-inflammatory agents [16, 17]. In addi-
tion, the heterocyclic nitrogen derivatives exhibited
a general ionophoric potency for divalent cations
[18] and are used as novel thiocyanate-selective
membrane sensors [19]. Recently, we reported that
certain substituted heterocyclic compounds exhib-
ited antiparkinsonian, anti-inflammatory, antimi-
crobial, and anticonvulsant activities [20–24]. In
ꢀ
hotmail.com
Corresponding author. E-mail: Mohamed_mostafa211@

1020
A. F. A. Shalaby et al.
view of these observations and in continuation of
our previous work in heterocyclic chemistry, we
synthesized some new heterocyclic compounds con-
taining pyridone, pyridinethione, pyrazoline, and
pyrimidine rings and tested their anti-arrhythmic
activities.
Scheme 1

Heterocyclic Systems Using 5-Chloroanisic Acid
Results and Discussion
Synthesis
1021
ing to the mixed anhydride technique [16] providing
2, followed by treating with 4-fluorobenzaldehyde
in ethanolic piperidine to afford N1-[4-(4-fluoro-
cinnamoyl)phenyl]-5-chloro-2-methoxybenzamide 3.
Cyclocondensation of 3 with hydrazine hydrate in
The starting material 3 was synthesized from 5-chlo-
roanisic acid (1) and p-aminoacetophenone accord-
Scheme 2

1022
A. F. A. Shalaby et al.
refluxing dioxane afforded the pyrazoline 4, which
was treated with morpholine in the presence of para-
formaldehyde to give the N-morpholinomethylpyr-
azoline 5. But 4 was reacted with acetyl chloride
in dioxane to yield the 1-acetylpyrazoline 6, which
was also prepared directly from 3 by the action of
Scheme 3

Heterocyclic Systems Using 5-Chloroanisic Acid
1023
Table 1. Anti-arrhythmic activities of the newly synthesized
compounds
hydrazine hydrate in the presence of an acetic
acid=acetic anhydride mixture. Also, 3 was treated
with methylhydrazine or phenylhydrazine to yield
N-methylpyrazoline 7 and N-phenylpyrazoline 8.
Condensation of 3 with ethyl cyanoacetate in the
presence of sodium ethoxide in ethanol gave cyano-
pyrane 9, but in the presence of ammonium acetate
in n-butanol afforded cyanopyridone 10, which was
prepared also from 3 with cyanoacetamide under the
same conditions (Scheme 1).
Condensation of 3 with cyanothioacetamide in
the presence of ammonium acetate in n-butanol
yielded pyridinethione 11, which was treated with
ethyl chloroacetate in the presence of EtONa to
give ethyl-3-aminothieno[2,3-b]pyridine-2-carbox-
ylate derivative 12. But, 3 was condensed with
malononitrile in refluxing n-butanol in the pres-
ence of ammonium acetate, which gave the cyano-
aminopyridine 13. In addition, 3 was reacted with
ethyl acetoacetae in the presence of EtONa to
yield ethyl 3-cyclohexene-1-carboxylate 14, which
was then reacted with methylhydrazine in reflux-
ing ethanol to afford the N-methylpyrazolone 15
(Scheme 2).
Compound in (5 mg=kg) Percentage increase in LD100=%
3
4
5
76 ꢂ 0.081
77 ꢂ 0.092
no effect
6
7
8
9
48 ꢂ 0.046
65 ꢂ 0.063
67 ꢂ 0.066
72 ꢂ 0.072
54 ꢂ 0.050
no effect
10
11
12
13
14
15
16
17
18
19
20
21
77 ꢂ 0.077
no effect
79 ꢂ 0.071
no effect
47 ꢂ 0.041
37 ꢂ 0.051
75 ꢂ 0.081
86 ꢂ 0.091
45 ꢂ 0.051
78 ꢂ 0.099
All data were significantly different from the normal control
value at P ꢃ 0.05
On the other hand, reaction of 3 with acetylace-
tone in the presence of EtONa afforded 4-acetyl-
3-oxo-1-cyclohexene 16, which was treated with
hydrazine hydrate in ethanol to give the 3-methyl-
pyrazoline derivative 17. Condensation of 3 with
diamino reagents, namely, guanidine hydrochloride
or thiourea in methanolic MeONa afforded the cor-
responding aminopyrimidine 18 and thioxopyrimi-
dine 19. Also, 19 was condensed with chloroacetic
acid in a mixture of acetic acid=acetic anhydride in
the presence of anhydrous sodium acetate to yield
the corresponding thiazolopyrimidine 20, which was
condensed with 2-thiophenealdehyde in the presence
of anhydrous sodium acetate and a glacial acetic
acid=acetic anhydride mixture to yield arylmethy-
lene derivative 21. However, the latter compound
was also prepared directly from 19 by the action of
chloroacetic acid, 2-thiophenealdehyde, and anhy-
drous sodium acetate in the presence of acetic acid=
acetic anhydride mixture (Scheme 3).
From Table 1, compounds 5, 11, 13, and 15 show-
ed no anti-arrhythmic activities but compounds 7
and 8 displayed nearly equal anti-arrhythmic activ-
ities as procaine amide and lidocaine. Compounds 3,
4, 9, 10, 12, 14, 19, 21, and 18 are more active than
procaine amide and lidocaine, they arranged in de-
scending manner. Also, 6, 10, 16, 20, and 17 showed
anti-arrhythmic activities less than procaine and
lidocaine, they arranged in descending manner.
Structural Activity Relationship (SAR)
ꢁ The benzylidene moiety and a high degree of aro-
maticity is essential for anti-arrhythmic activity.
ꢁ Hetero-aromaticity increases the anti-arrhythmic
activity.
ꢁ Fused ring systems give anti-arrythmic activity
but to a lower extent.
Determination of Acute Toxicity (LD50)
The LD50 was determined by using rats. They were
injected with different increasing doses of the syn-
thesized compounds. The dose that killed 50% of
the animals was calculated according to Austen and
Brocklehurst [25].
Pharmacological Screening
Procaine amide, 5 mg=kg iv, and lidocaine, 5 mg=kg
iv, led to an increase in LD100 by 65%, which corre-
sponds to a LD100 of approximately 9 ꢀg=100 mg.

1024
A. F. A. Shalaby et al.
Table 2. Acute toxicity (LD50) of the synthesized compounds
N1-f4-[5-(4-Fluorophenyl)-4,5-dihydro-1H-3-pyrazolyl]
phenylg-5-chloro-2-methoxybenzamide (4, C23H19FClN3O2)
A solution of 0.41 g 3 (1mmol) and 0.4 cm3 hydrazine hydrate
(8mmol) in 20cm3 dioxane was refluxed for 2 h. The solvent
was evaporated under reduced pressure, the residue was wash-
ed with n-hexane and crystallized to give 0.3 g 4 (71%). Mp
201–202ꢄC (MeOH); IR (film): ꢁꢀ¼ 3435–3285 (NH), 1698
Compound no.
LD50=mg kgꢅ1
3
4
5
6
7
242.52 ꢂ 0.27
297.76 ꢂ 0.25
294.33 ꢂ 0.15
298.85 ꢂ 0.19
238.87 ꢂ 0.17
298.67 ꢂ 0.22
317.99 ꢂ 0.11
387.49 ꢂ 0.19
309.29 ꢂ 0.18
309.99 ꢂ 0.22
374.33 ꢂ 0.27
274.37 ꢂ 0.29
285.89 ꢂ 0.23
242.29 ꢂ 0.29
338.44 ꢂ 0.18
226.62 ꢂ 0.19
278.22 ꢂ 0.27
276.01 ꢂ 0.19
298.22 ꢂ 0.12
1
(CO) cmꢅ1; H NMR (CDCl3): ꢂ ¼ 2.15–2.24 (d, CH2-pyra-
zoline), 3.52 (s, OCH3), 3.86 (m, CH-pyrazoline), 6.95 (s, NH,
exchangeable with D2O), 7.28–7.94 (m, Ar–H), 10.55 (s, NH,
exchangeable with D2O) ppm; 13C NMR (CDCl3): ꢂ ¼ 56.19
(OCH3), 165.10 (CONH2), 45.71, 62.65, 156.10 (pyrazoline-
C), 115.70, 118.60, 123.0, 128.40, 128.90, 129.30, 131.30,
133.81, 133.90, 139.40, 141.50, 147.90, 148.01, 161.65 (Ar–
C) ppm; MS (EI, 70eV): m=z (%) ¼ 424 [Mþ, 16] and at 328
(100, base peak).
8
9
10
11
12
13
14
15
16
17
18
19
20
21
N1-f4-[N-Morpholinomethyl)-5-(4-fluorophenyl)-4,5-dihydro-
1H-3-pyrazolyl]phenylg-5-chloro-2-methoxybenzamide
(5, C28H28FClN4O3)
A mixture of 0.424 g 4 (1mmol), ꢆ0.1g morpholine (1 mmol),
and 0.2 g paraformaldehyde in 30cm3 absolute ethanol was
refluxed for 2 h. The reaction mixture was evaporated under
reduced pressure, dried, and crystallized to give 0.29g 5
(56%). Mp 118–120ꢄC (MeOH); IR (film): ꢁꢀ¼ 3386–3156
All data were significantly different from the normal control
value at P ꢃ 0.05
(NH), 1692 (CO) cmꢅ1
;
1H NMR (CDCl3): ꢂ ¼ 2.05–2.20
(d, CH2-pyrazoline), 2.40–2.45 (m, CH2-morpholine), 3.31–
3.35 (m, CH2-morpholine), 3.56 (s, OCH3), 3.81 (s, N–CH2–
N), 3.88 (m, CH-pyrazoline), 7.43–8.17 (m, Ar–H), 10.66 (s,
NH, exchangeable with D2O) ppm; MS (EI, 70eV): m=z
(%) ¼ 523 [Mþ, 22] and at 119 (100, base peak).
Experimental
All melting points were taken on Electrothermal IA 9000
series digital melting point apparatus. Elemental analytical
data (in accord with the calculated values) were obtained
from the microanalytical unit, Cairo University, Cairo,
Egypt. The IR spectra (KBr) were recorded on a Shimadzu
CVT-04 spectrophotometer. The 1H NMR spectra were
recorded at 270 MHz on a Varian EM-360 spectrometer using
TMS as an internal standard. The mass spectra were performed
using a Varian MAT CH-5 spectrometer (70 eV). All reactions
N1-f4-[1-Acetyl-5-(4-fluorophenyl)-4,5-dihydro-1H-3-
pyrazolyl]phenylg-5-chloro-2-methoxybenzamide
(6, C25H21FClN3O3)
Method A: A mixture of 0.424 g 4 (1 mmol) and ꢆ0.1 g
acetyl chloride (1 mmol) in 30 cm3 dioxane was stirred at
room temperature for 5 h. The reaction mixture was evapo-
rated under reduced pressure, the product was extracted with
dichloromethane, washed with aqueous sodium bicarbonate,
dried over anhydrous MgSO4, evaporated under reduced
pressure, and crystallized to give 0.37 g 6 (80%). Mp 266–
268ꢄC (MeOH); IR (film): ꢁꢀ¼ 3320–3100 (NH), 1718, 1694
(2CO) cmꢅ1; 1H NMR (CDCl3): ꢂ ¼ 1.85 (s, CH3), 2.10–2.18
(m, CH2-pyrazoline), 3.53 (s, OCH3), 3.85 (m, CH-pyrazo-
line), 7.26–7.98 (m, Ar–H), 10.46 (s, NH, exchangeable with
D2O) ppm; MS (EI, 70eV): m=z (%) ¼ 466 [Mþ, 8] and at 280
(100, base peak).
Method B: A mixture of 0.41 g 3 (1mmol) and 0.4 cm3
hydrazine hydrate (8mmol) in 40cm3 AcOH=Ac2O (3=1)
was refluxed for 3 h, allowed to cool, and then poured onto
water. The obtained solid was filtered off and crystallized to
give 0.34 g 6 (72%).
were followed by TLC (silica gel, aluminum sheets 60 F254
Merck).
,
N1-[4-(4-Fluorocinnamoyl)phenyl]-5-chloro-2-
methoxybenzamide (3, C23H17FClNO3)
A mixture of 0.303 g acetyl derivative 2 (1 mmol), 0.124 g
4-fluorobenzaldehyde (1 mmol) in 20 cm3 absolute etha-
nol and 0.5 cm3 piperdine was refluxed for 30 min. The
reaction mixture was left overnight at room tempera-
ture, the obtained solid was filtered off and crystallized to
give 0.35 g 3 (87%). Mp 268–269ꢄC (EtOH); IR (film):
1
ꢁꢀ¼ 3340–3240 (NH), 1698, 1679 (2CO) cmꢅ1; H NMR
(CDCl3): ꢂ ¼ 3.57 (s, OCH3), 6.91 (d, CH-arylidene), 7.23–
7.78 (m, Ar–H þ CH-arylidene), 10.66 (s, NH, exchange-
able with D2O) ppm; 13C NMR (CDCl3): ꢂ ¼ 57.10 (OCH3),
164.98, 188.96 (2C¼O), 129.10, 155.20 (C¼C), 133.79,
127.90, 134.60, 128.70, 115.22, 159.50, 139.90, 117.40,
129.10, 142.70, 136.70, 130.0, 124.18, 148.90 (Ar–C) ppm;
MS (EI, 70 eV): m=z (%) ¼ 410 [Mþ, 12] and at 268 (100,
base peak).
N1-f4-[1-Substituted-5-(4-fluorophenyl)-4,5-dihydro-1H-3-
pyrazolyl]phenylg-5-chloro-2-methoxybenzamide 7 and 8
General procedure: A solution of 0.41 g 3 (1mmol) and
methylhydrazine or phenylhydrazine (1.5 mmol) in 15 cm3

Heterocyclic Systems Using 5-Chloroanisic Acid
1025
absolute ethanol was refluxed for 5 h. The reaction mixture
was poured onto ice, the obtained solid was collect by filtra-
tion, dried, and crystallized to give 0.25 g 7 (58%) and 0.31g 8
(62%).
H þ CH-pyridine), 8.72 (s, NH exchangeable with D2O),
10.55 (s, NH, exchangeable with D2O) ppm; MS (EI, 70 eV):
m=z (%) ¼ 474 [Mþ, 22] and at 238 (100, base peak).
Method B: A solution of 0.41 g 3 (1mmol), 0.1 g cyano-
acetamide (1.2 mmol), and 0.616 g ammonium acetate
(8mmol) in 20cm3 n-butanol was refluxed for 2 h. After cool-
ing, the solid formed was filtered off, dried, and crystallized to
give 0.34 g 10 (72%).
N1-f4-[1-Methyl-5-(4-fluorophenyl)-4,5-dihydro-1H-3-
pyrazolyl]phenylg-5-chloro-2-methoxybenzamide
(7, C24H21FClN3O2)
Mp 273–275ꢄC (MeOH); IR (film): ꢁꢀ¼ 3360–3105 (NH),
N1-f4-[3-Cyano-2-thioxo-6-(4-fluorophenyl)-1,2-dihydro-4-
pyridinyl]phenylg-5-chloro-2-methoxybenzamide
1699 (CO) cmꢅ1
;
1H NMR (CDCl3): ꢂ ¼ 2.10–2.25 (d,
CH2-pyrazoline), 2.57 (s, N–CH3), 3.54 (s, OCH3), 3.87 (m,
CH-pyrazoline), 7.13–7.96 (m, Ar–H), 10.60 (s, NH, ex-
changeable with D2O) ppm; 13C NMR (CDCl3): ꢂ ¼ 36.60
(N–CH3), 55.20 (OCH3), 164.91 (CONH), 43.20, 67.69,
155.10 (pyrazoline-C), 115.24, 117.10, 118.90, 120.14,
127.90, 128.40, 128.80, 129.59, 131.09, 133.70, 135.10,
139.10, 139.70, 158.10 (Ar–C) ppm; MS (EI, 70 eV): m=z
(%) ¼ 438 [Mþ, 16] and at 186 (100, base peak).
(11, C26H17ClFN3O2S)
A solution of 0.41g 3 (1mmol), 0.12g cyanothioacetamide
(1.2mmol), and 0.616g ammonium acetate (8mmol) in 25cm3
n-butanol was refluxed for 3 h. After cooling the precipitated
was filtered off, dried, and crystallized to give 0.45g 11 (92%).
Mp 148–150ꢄC (toluene); IR (film): ꢁꢀ¼ 3460–3250 (NH),
1
2219 (CN), 1697 (CO), 1230 (CS) cmꢅ1; H NMR (CDCl3):
ꢂ ¼ 3.59 (s, OCH3), 4.56 (s, CSNH, exchangeable with D2O),
7.15–8.11 (m, Ar–H þ CH-pyridinethione), 10.64 (s, NH,
exchangeable with D2O) ppm; 13C NMR (CDCl3): ꢂ ¼ 56.19
(OCH3), 117.80 (CN), 164.92 (CONH), 112.86, 138.90,
145.36, 163.75, 171.50 (pyridine-C), 112.82, 112.90, 118.10,
126.80, 127.77, 129.70, 129.87, 134.09, 134.18, 140.90,
141.20, 145.36, 153.10, 163.75 (Ar–C) ppm; MS (EI, 70 eV):
m=z (%) ¼ 490 [Mþ, 65] and at 229 (100, base peak).
N1-f4-[1-Phenyl-5-(4-fluorophenyl)-4,5-dihydro-1H-3-
pyrazolyl]phenylg-5-chloro-2-methoxybenzamide
(8, C29H23FClN3O2)
Mp 218ꢄC (MeOH); IR (film): ꢁꢀ¼ 3350–3145 (NH), 1692
1
(CO) cmꢅ1; H NMR (CDCl3): ꢂ ¼ 1.99–2.16 (d, CH2-pyr-
azoline), 3.56 (s, OCH3), 3.91 (m, CH-pyrazoline), 7.10–7.98
(m, Ar–H), 10.58 (s, NH, exchangeable with D2O) ppm; MS
(EI, 70 eV): m=z (%) ¼ 500 [Mþ, 100, base peak].
Ethyl 3-amino-4-f4-[(5-chloro-2-methoxybenzoyl)amino]-
phenylg-6-(4-fluorophenyl)thieno[2,3-b]pyridine-2-
carboxylate (12, C30H23FClN3O4S)
N1-f4-[3-Cyano-2-oxo-6-(4-fluorophenyl)-2H-4-pyranyl]-
phenylg-5-chloro-2-methoxybenzamide (9, C26H16ClFN2O4)
A solution of 0.41 g 3 (1mmol), 0.13cm3 ethyl cyanoacetate
(1.2mmol), and 68mg of sodium ethoxide (1mmol) in 20cm3
absolute ethanol was refluxed for 2 h. The reaction mixture
was evaporated under reduced pressure, the residue was soli-
dified with n-hexane, the obtained solid was filtered off, and
crystallized to give 0.32 g 9 (67%). Mp 267–269ꢄC (MeOH=
toluene); IR (film): ꢁꢀ¼ 3405–2900 (NH), 2226 (CN), 1715,
A solution of 0.5 g 11 (1mmol), 0.122g ethyl chloroacetate
(1mmol), and 0.68 g sodium ethoxide (10 mmol) in 10 cm3
ethanol was refluxed for 4 h. The reaction mixture was evapo-
rated under reduced pressure, the obtained solid was filtered
off, dried, and crystallized to give 0.4 g 12 (70%). Mp 301–
303ꢄC (MeOH=methylacetate); IR (film): ꢁꢀ¼ 3490–3265
(NH, NH2), 1735, 1693 (2CO) cmꢅ1 1H NMR (CDCl3):
;
ꢂ ¼ 1.10 (t, CH3), 3.62 (s, OCH3), 4.51 (q, OCH2), 5.75 (s,
NH2, exchangeable with D2O), 7.12–7.97 (m, Ar–H þ CH-pyr-
idine), 10.66 (s, NH, exchangeable with D2O) ppm; MS (EI,
70eV): m=z (%) ¼ 576 [Mþ, 15] and at 530 (100, base peak).
1
1698 (2CO) cmꢅ1; H NMR (CDCl3): ꢂ ¼ 3.53 (s, OCH3),
7.01 (s, pyrane-H), 7.12–7.96 (m, Ar–H), 10.58 (s, NH, ex-
changeable with D2O) ppm; 13C-NMR (CDCl3): ꢂ ¼ 56.38
(OCH3), 117.88 (CN), 163.78 (CONH), 106.08, 131.08,
145.10, 154.70, 157.78 (pyrane-C), 114.73, 116.50, 117.88,
128.15, 129.47, 129.84, 130.25, 133.90, 134.09, 139.90,
144.91, 144.98, 153.17, 166.60 (Ar–C) ppm; MS (EI, 70 eV):
m=z (%) ¼ 475 [Mþ, 32] and at 351 (100, base peak).
N1-f4-[6-Amino-5-cyano-2-(4-fluorophenyl)-4-pyridyl)-
phenyl]g-5-chloro-2-methoxybenzamide (13, C26H18ClN4O2)
A solution of 0.41 g 3 (1 mmol), ꢆ0.1 g malononitril
(1.2 mmol), and 0.616 g ammonium acetate (8 mmol) in
25cm3 n-butanol was refluxed for 3 h. After cooling, the pre-
cipitate was filtered off, dried, and crystallized to give 0.34g
13 (72%). Mp 228–230ꢄC (acetone=MeOH); IR (film):
N1-f4-[3-Cyano-2-oxo-6-(4-fluorophenyl)-1,2-dihydro-4-
pyridinyl]phenylg-5-chloro-2-methoxybenzamide
ꢁꢀ¼ 3460–3250 (NH, NH2), 2223 (CN), 1694 (CO) cmꢅ1
;
1H NMR (CDCl3): ꢂ ¼ 3.51 (s, OCH3), 5.45 (s, NH2, ex-
changeable with D2O), 6.96–7.97 (m, Ar–H þ CH-pyridine),
10.64 (s, NH, exchangeable with D2O) ppm; 13C NMR
(CDCl3): ꢂ ¼ 56.19 (OCH3), 116.10 (CN), 164.75 (CONH),
111.50, 137.43, 145.10, 163.80, 176.11 (pyridine-C), 111.68,
113.10, 117.90, 125.60, 127.55, 129.10, 130.25, 134.10,
134.17, 141.10, 141.80, 143.20, 154.74, 163.88 (Ar–C) ppm;
MS (EI, 70eV): m=z (%) ¼ 473 [Mþ, 100, base peak].
(10, C26H17FClN3O3)
Method A: A solution of 0.41g 3 (1mmol), 0.13cm3 ethyl
cyanoacetate (1.2mmol), and 0.616 g ammonium acetate
(8mmol) in 20cm3 n-butanol was refluxed for 2 h. The formed
precipitate after cooling was filtered off, dried, and crystallized
to give 0.32 g 10 (68%). Mp 258–260ꢄC (EtOH); IR (film):
ꢁꢀ¼ 3452–2685 (NH), 2218 (CN), 1696, 1678 (2CO) cmꢅ1
;
1H NMR (CDCl3): ꢂ ¼ 3.55 (s, OCH3), 7.22–8.12 (m, Ar–

1026
A. F. A. Shalaby et al.
for 3 h. The separated solid was filtered off and crystallized
to give 0.42 g 17 (87%). Mp 163–165ꢄC (EtOH); IR (film):
Ethyl 4-f4-[(5-chloro-2-methoxybenzoyl)amino]phenylg-2-
oxo-6(S)-(4-fluorophenyl)-3-cyclohexene-1(S)-carboxylate
(14, C29H25FClNO5)
1
ꢁꢀ¼ 3340–3180 (NH), 1697 (CO, amide) cmꢅ1; H NMR
A solution of 0.41 g 3 (1 mmol), 0.15 cm3 ethyl acetoacetate
(1.2 mmol), and ꢆ0.1 g sodium ethoxide (1.5 mmol) in
25 cm3 absolute ethanol was refluxed for 3 h. The reaction
mixture was evaporated under reduced pressure, the residue
was crystallized to give 0.48 g 14 (92%). Mp 164–166ꢄC
(EtOH); IR (film): ꢁꢀ¼ 33100–2980 (NH), 1728, 1718, 1697
(3CO) cmꢅ1; 1H NMR (CDCl3): ꢂ ¼ 1.05 (t, CH3), 2.49 (m,
CH2-cyclohexene), 3.52 (s, OCH3), 3.78 (d, CH-cyclohex-
ene), 3.88 (m, CH-cyclohexene), 4.18 (m, OCH2), 6.57 (s,
CH-ene), 7.10–7.96 (m, Ar–H), 10.72 (s, NH, exchangeable
with D2O) ppm; MS (EI, 70eV): m=z (%) ¼ 522 [Mþ, 7] and
at 279 (100, base peak).
(CDCl3): ꢂ ¼ 1.98 (s, CH3), 3.28 (m, CH2-indazolyl), 3.58
(s, OCH3), 3.79 (m, CH-indazolyl), 4.09 (m, CH-indazolyl),
6.78 (s, CH-indazolyl), 7.12–7.89 (m, Ar–H), 10.65 (s,
NH, exchangeable with D2O) ppm; 13C NMR (CDCl3):
ꢂ ¼ 17.40 (CH3), 56.17 (OCH3), 163.16 (CONH), 36.61,
39.31, 51.11, 134.18, 143.60, 144.80, 154.10 (indazolyl-
C), 113.18, 117.56, 118.17, 126.70, 129.35, 130.18, 130.38,
134.18, 138.16, 142.16, 143.21, 154.57, 154.81, 164.28 (Ar–
C) ppm; MS (EI, 70eV): m=z (%) ¼ 488 [Mþ, 14] and at 251
(100, base peak).
Substituted Pyrimidine Derivatives 18 and 19
A solution of 0.41 g 3 (1 mmol), diamino reagents, name-
ly, guanidine hydrochloride or thiourea (1.2 mmol) and
ꢆ0.1 g sodium methoxide (1.5 mmol) in 25 cm3 absolute
methanol was refluxed for 2–4 h. The reaction mixture
was evaporated to dryness under reduced pressure, dried
and crystallized to give 0.41 g 18 (91%) and 0.30 g 19
(65%).
N1-[4-(3-Oxo-4-(4-fluorophenyl)-3,3a(S),4(S),5-tetrahydro-
2-methyl-2H-6-indazolyl)phenyl]-5-chloro-2-
methoxybenzamide (15, C28H23FClN3O3)
A solution of 0.522 g 14 (1mmol) and 0.46g methylhydra-
zine (1mmol) in 10cm3 absolute ethanol was refluxed for
1.5 h. The reaction mixture was left overnight at room tem-
perature, the obtained solid was filtered off and crystallized to
give 0.24g 15 (48%). Mp 154–156ꢄC (EtOH); IR (film):
N1-f4-[2-Amino-6-(4-fluorophenyl)-4-pyrimidinyl]phenyl]g-
5-chloro-2-methoxybenzamide (18, C24H20FClN4O2)
Mp 210–212ꢄC (AcOMe); IR (film): ꢁꢀ¼ 3450–3200 (NH,
ꢁꢀ¼ 3375–3205 (NH), 1715, 1694 (2CO) cmꢅ1
;
1H NMR
(CDCl3): ꢂ ¼ 2.54 (s, CH3), 2.70 (m, CH2-indazolyl), 3.14
(d, CH-indazolyl), 3.52 (d, CH-indazolyl), 3.62 (s, OCH3),
6.78 (s, CH-indazolyl), 7.21–8.05 (m, Ar–H), 10.48 (s, NH,
exchangeable with D2O) ppm; MS (EI, 70 eV): m=z (%) ¼ 504
[Mþ, 100, base peak].
NH2), 1696 (CO) cmꢅ1
;
1H NMR (CDCl3): ꢂ ¼ 3.53 (s,
OCH3), 5.18 (d, Ha-pyrimidine), 5.46 (s, NH2, exchangeable
with D2O), 6.98–8.04 (m, Ar–H þ Hb-pyrimidine), 8.40 (s,
NH, exchangeable with D2O), 10.42 (s, NH, exchangeable
with D2O) ppm; MS (EI, 70eV): m=z ¼ 451 [Mþ, 12] and
at 200 (100, base peak).
N1-f4(R)-[4-Acetyl-3-oxo-5(R)-(4-fluorophenyl)-1-
cyclohexenyl]phenylg-5-chloro-2-methoxybenzamide
(16, C28H23FClNO4)
N1-f4-[6-(4-Fluorophenyl)-2-thioxo-4-pyrimidinyl]phenyl]g-
5-chloro-2-methoxybenzamide (19, C24H19FClN3O2S)
Mp 230–232ꢄC (AcOMe); IR (film): ꢁꢀ¼ 3460–3210 (NH),
A solution of 0.41 g 3 (1mmol), 0.12cm3 acetyl acetone
(1.2mmol) and ꢆ0.1 mg sodium ethoxide (1.5mmol) in
10cm3 absolute ethanol was refluxed for 2 h. The reaction
mixture was evaporated under reduced pressure, the residue
was crystallized to give 0.46 g 16 (94%). Mp 213–215ꢄC
(acetone=MeOH); IR (film): ꢁꢀ¼ 3380–3190 (NH), 1728,
1
1697 (CO), 1225 (CS) cmꢅ1; H NMR (CDCl3): ꢂ ¼ 3.58
(s, OCH3), 5.22 (d, Ha-pyrimidine), 7.24–8.31 (m, Ar–
H þ Hb-pyrimidine), 8.42 and 8.54 (2s, 2NH, exchange-
able with D2O), 10.65 (s, NH, exchangeable with D2O)
ppm; MS (EI, 70 eV): m=z (%) ¼ 468 [Mþ, 100, base
peak].
1710, 1699 (3CO) cmꢅ1
;
1H NMR (CDCl3): ꢂ ¼ 1.84 (s,
COCH3), 2.67 (m, CH2-cyclohexene), 3.54 (s, OCH3), 3.76
(m, CH-cyclohexene), 3.83 (m, CH-cyclohexene), 6.84 (s,
CH-cyclohexene), 7.12–7.89 (m, Ar–H), 10.66 (s, NH,
exchangeable with D2O) ppm; 13C NMR (CDCl3): ꢂ ¼ 29.70
(CH3), 56.91 (OCH3), 163.40 (CONH), 36.46, 40.49, 68.10,
132.25, 159.68, 198.31 (cyclohexenone-C), 207.11 (CO),
113.20, 117.33, 117.80, 124.89, 126.91, 129.0, 130.28,
134.80, 135.60, 142.60, 142.70, 151.60, 154.70, 164.11 (Ar–
C) ppm; MS (EI, 70 eV): m=z (%) ¼ 492 [Mþ, 20] and at 381
(100, base peak).
7-f4-[4-(5-Chloro-2-methoxybenzoyl)amino]phenylg-3-oxo-
5-(4-fluorophenyl)-2,3-dihydro-5H-thiazolo[3,2-a]-
pyrimidine (20, C26H19FClN3O3S)
A mixture of 0.468 g 19 (1 mmol) and 0.1 g chloroacetic
acid (1 mmol) was dissolved in 40 cm3 AcOH=Ac2O (1=3)
in the presence of 1.5 g anhydrous sodium acetate and was
refluxed for 6 h. The reaction mixture was cooled and
poured onto cold water with stirring, the formed solid
was filtered off and crystallized to give 0.35 g (68%) 20.
Mp 188–190ꢄC (AcOH=H2O); IR (film): ꢁꢀ¼ 3355–3295
N1-f4-[3-Methyl-4-(4-fluorophenyl)-4,5-dihydro-3a(R)H-6-
indazolyl]phenylg-5-chloro-2-methoxybenzamide
(17, C28H23FClN3O2)
A solution of 0.5 g 16 (1 mmol) and 0.4 cm3 hydrazine
hydrate (8 mmol) in 5 cm3 absolute ethanol was refluxed
(NH), 1735, 1698 (2CO) cmꢅ1 1H NMR (DMSO-d6):
;
ꢂ ¼ 3.53 (s, OCH3), 3.72 (s, CH2-thiazole), 5.52 (d, Ha,
pyrimidine), 7.26–7.50 (m, Ar–H þ Hb-pyrimidine), 10.25

Heterocyclic Systems Using 5-Chloroanisic Acid
1027
(s, NH, exchangeable with D2O) ppm; MS (EI, 70eV): m=z
(%) ¼ 508 [Mþ, 10] and at 228 (base peak, 100).
References
[1] Amr AE, Hegab MI, Ibrahiem AA, Abdulla MM (2003)
Monatsh Chem 134: 1395
7-f4-[4-(5-Chloro-2-methoxybenzoyl)amino]phenylg-2-
(2-thienylmethylene)-3-oxo-5-(4-fluorophenyl)-2,3-dihydro-
5H-thiazolo[3,2-a]pyrimidine (21, C31H21FClN3O3S2)
Method A: A mixture of 0.468 g 19 (1mmol), 0.1g chloro-
acetic acid (1mmol), and 1.5 g anhydrous sodium acetate in
40cm3 AcOH=Ac2O (1=3) and 0.112 g 2-thiophenealdehyde
(1mmol) was refluxed for 6 h. The reaction mixture was
cooled and poured onto ice-water, the obtained solid was
collected by filtration, and crystallized to give 0.5 g (84%)
21. Mp 212–214ꢄC (AcOH=H2O); IR (film): ꢁꢀ¼ 3355–3325
[2] Amr AE, Abdel-Latif NA, Abdalla MM (2006) Bioorg
Med Chem 14: 273
[3] Amr AE, Sayed HH, Abdulla MM (2005) Arch Pharm
Chem Life Sci 338: 433
[4] Amr AE (2005) Z Naturforsch 60b: 90
[5] Amr AE, Abdel-Latif NA, Abdalla MM (2006) Acta
Pharm 56: 203
[6] Attia A, Abdel-Salam OI, Amr AE (1997) Egypt J Chem
40: 317
[7] Attia A, Abdel-Salam OI, Stibor I, Amr AE, Budesinsky
M (2000) Egypt J Chem 43: 187
[8] Attia A, Abdel-Salam OI, Amr AE (2000) Egypt J Chem
43: 297
[9] Amr AE (2000) Ind J Heterocycl Chem 10: 49
[10] Amr AE, Mohamed AM, Ibrahim AA (2003) Z
Naturforsch 58b: 861
[11] Hammam AG, Fahmy AFM, Amr AE, Mohamed AM
(2003) Ind J Chem 42B: 1985
1
(NH), 1716, 1694 (2CO) cmꢅ1; H NMR (DMSO-d6): ꢂ ¼
3.58 (s, OCH3), 5.56 (d, Ha, pyrimidine), 7.32–7.65 (m, Ar–
H þ Hb-pyrimidineþ benzylic protonþ thiophen-H), 10.15 (s,
NH, exchangeable with D2O) ppm; MS (EI, 70 eV): m=z
(%) ¼ 602 [Mþ, 100, base peak].
Method B: A mixture of 0.5 g 20 (1mmol) and 0.112g 2-
thiophenealdehyde (1mmol) in 40 cm3 AcOH=Ac2O (1=3)
was refluxed for 5 h, allowed to cool, then poured onto water,
the solid formed was collected by filtration, and crystallized to
yield 0.42g (72%) 21, as identified by its mp, mixed mp, and
Rf value on TLC by comparison with authentic sample from
method A.
[12] Hammam AG, Abdel Hafez NA, Midura WH,
Mikolajczyk M (2000) Z Naturforsch 55b: 417
[13] Hammam AG, Sharaf M, Abdel-Hafez NA (2001) Ind J
Chem 40B: 213
[14] Hammam AG, Magdy AZ, Fatma AE, Khalid MHH
(1996) Egypt J Pharm Sci 37: 565
Pharmacological Assay
[15] Hammam AG, Zaki MEA, El-Assasy ME (1997) Egypt J
Pharm Sci 38: 292
[16] Abo-Ghalia M, Amr AE (2004) Amino Acids 26: 283
[17] Abo-Ghalia M, Amr AE, Abdulla MM (2003) Z
Naturforsch 58b: 903
Anti-arrhythmic Activity [26–31]
Purpose and Rational
The plant alkaloid aconitine persistently activates sodium
channel. Infusion of aconitine in the anesthetized rat causes
ventricular arrhythmias. Drugs considered to have anti-ar-
rhythmic properties can be tested in aconitine-intoxicated rats.
[18] Hassan SSM, Abou-Ghalia MH, Amr AE, Mohamed
AHK (2003) Talanta 60: 81
[19] Hassan SSM, Abou-Ghalia MH, Amr AE, Mohamed
AHK (2003) Anal Chem Acta 482: 9
Procedure
Male Ivanovas rats weighing 300–350 g are used. The animals
are anesthetized by intra peritoneal injection of 1.25g=kg
urethane: 5 mg=kg aconitine dissolved in 0.1 N HNO3 is admi-
nistered by continuous infusion into the saphenous vein of
0.1 cm3=min and the ECG in lead II is recorded every 30sec.
The test compound is injected IV at a screening dose of
3 mg=kg 5 min before the start of the aconitine infusion, 24
animals are used per compound.
[20] Amr AE, Abdalla MM (2006)Bioorg Med Chem 14: 4341
[21] Amr AE, Abdalla MM (2006) Arch Pharm Chem Life
Sci 339: 88
[22] Amr AE, Nermien MS, Mohamed MA (2007) Monatsh
Chem Accepted in 10-1-2007
[23] Amr AE (2006) Z Naturforsch 61b: 1335
[24] Amr AE, Ashraf MM, Salwa FM, Nagla AA, Hammam
AG (2006) Bioorg Med Chem 14: 5481
[25] Austen KF, Brocklehurst WE (1961) J Exp Med 113: 521
[26] Walker MJA, Curtius MJ, Hearse DJ, Campbell RWF,
Jams MJ, Yellon DM, Coker SM, Harness JB, Harron
DWG, Miggins AJ, Julian DG, Lab MJ, Manning AS,
Northover BJ, Parratt JR, Riemrsma RA, Riva E, Russell
DC, Sheridan DJ, Winslow E, Woodward B (1988)
Cardiovasc Res 22: 447
[27] Vaille A, Scotto di Tella AM, Maldonado J, Vanelle P
(1992) Meth Find Exp Clin Pharmacol 14: 183
[28] Bazzani C, Genedani S, Tugliavini S, Bertolini A (1989)
J Pharm Pharmacol 41: 651
Evaluation
The anti-arrhythmic effect of a test compound is measured by
the amount of aconitine=100 g animal.
(Duration of infusion) which induces.
– Ventricular extra systoles.
– Ventricular tachycardia.
– Ventricular fibrillation.
Higher doses of aconitine in the treated group as compared to
an untreated control group are an indication of anti-arrhythmic
activity.
Statistical significance between the groups is assessed by
the Student’s T-test.
[29] DeClerk FLUHR (1993) J Cardiovasc Pharmacol 22: 120
[30] Winslow E (1980) Br J Pharmac 71: 615
[31] Winslow E (1981) J Cardiovasc Pharmac 3: 87