Conversion of 5-aryl-3-phenylthio-2(3H)-furanones into some nitrogen- and sulphur-containing heterocycles

Article abstract of DOI:10.1080/10426500600867349

3-Phenylthio-5-aryl-2(3H)-furanones 4 were prepared from 2-phenylthio- 3-aroylpropionic acids 3 by a ring closure using acetic anhydride. Benzylamine reacted with 4 to give the benzylamide derivatives 5, which were cyclized to the corresponding 2(3H)-pyrr

Full text of DOI:10.1080/10426500600867349

This article was downloaded by: [University of Waterloo]
On: 11 September 2013, At: 04:55
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954
Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH,
UK
Phosphorus, Sulfur, and Silicon
and the Related Elements
Publication details, including instructions for
authors and subscription information:
http://www.tandfonline.com/loi/gpss20
Conversion of 5-Aryl-3-
phenylthio-2(3H)-furanones
into Some Nitrogen-
and Sulphur-Containing
Heterocycles
Ahmed S. A. Youssef a , Kamal A. Kandeel a , Wael S.
I. Abou-Elmagd a & Ahmed I. Hashem a
a Chemistry Department, Ain Shams University,
Abassia, Cairo, Egypt
Published online: 01 Feb 2007.
To cite this article: Ahmed S. A. Youssef , Kamal A. Kandeel , Wael S. I. Abou-Elmagd
& Ahmed I. Hashem (2007) Conversion of 5-Aryl-3-phenylthio-2(3H)-furanones into
Some Nitrogen- and Sulphur-Containing Heterocycles, Phosphorus, Sulfur, and Silicon
and the Related Elements, 182:1, 85-97, DOI: 10.1080/10426500600867349
To link to this article: http://dx.doi.org/10.1080/10426500600867349
PLEASE SCROLL DOWN FOR ARTICLE
Taylor & Francis makes every effort to ensure the accuracy of all the
information (the “Content”) contained in the publications on our platform.
However, Taylor & Francis, our agents, and our licensors make no
representations or warranties whatsoever as to the accuracy, completeness,
or suitability for any purpose of the Content. Any opinions and views
expressed in this publication are the opinions and views of the authors, and
are not the views of or endorsed by Taylor & Francis. The accuracy of the
Content should not be relied upon and should be independently verified with
primary sources of information. Taylor and Francis shall not be liable for any

losses, actions, claims, proceedings, demands, costs, expenses, damages,
and other liabilities whatsoever or howsoever caused arising directly or
indirectly in connection with, in relation to or arising out of the use of the
Content.
This article may be used for research, teaching, and private study purposes.
Any substantial or systematic reproduction, redistribution, reselling, loan,
sub-licensing, systematic supply, or distribution in any form to anyone is
expressly forbidden. Terms & Conditions of access and use can be found at
http://www.tandfonline.com/page/terms-and-conditions

Phosphorus, Sulfur, and Silicon, 182:85–97, 2007
Copyright © Taylor & Francis Group, LLC
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426500600867349
Conversion of 5-Aryl-3-phenylthio-2(3H)-furanones into
Some Nitrogen- and Sulphur-Containing Heterocycles
Ahmed S. A. Youssef
Kamal A. Kandeel
Wael S. I. Abou-Elmagd
Ahmed I. Hashem
Chemistry Department, Ain Shams University, Abassia, Cairo, Egypt
3-Phenylthio-5-aryl-2(3H)-furanones
4 were prepared from 2-phenylthio-3-
aroylpropionic acids 3 by a ring closure using acetic anhydride. Benzylamine re-
acted with 4 to give the benzylamide derivatives 5, which were cyclized to the corre-
sponding 2(3H)-pyrrolones 6. The isothiazolone derivatives 7 were obtained from the
benzylamides 5 by the action of SOCl . A ring opening of furanone 4 with hydrazine
2
hydrate gave the acid hydrazides 8. The latter hydrazides were utilized as starting
materials for the synthesis of pyridazinone derivatives 9 and 11, 1,3,4-oxadiazoles
13, and triazolone derivatives 14.
Keywords 2(3H)-furanones; 1,3,4-oxadiazales; 2(3H)-pyrrolones; pyridazinones; 1,2,4-
triazolones
INTRODUCTION
2(3H)-furanones represent an important type of five-membered het-
erocycles of synthetic and biological importance. The products of a
ring opening of these compounds with nucleophiles are the precursors
of a wide variety of biologically important heterocyclic systems viz.
pyrrolones,1,2 pyridazinones,3,4 pyrazoles,5 1,3,4-oxadiazoles,6,7 and
triazoles.8
During an attempted ring opening of 3-aryl-5-phenyl-2(3H)-
furanones 1 with nitrogen nucleophiles, some of our research group
observed that instead of a ring opening, isomerization of furanones 1
into isomeric 2(5H)-furanones 2 occurred (Scheme 1).9
It was believed that such isomerization took place via the interme-
diacy of a carbanion intermediate initially formed at position 3, which
by resonance stabilization affected the migration of the double bond.
Received March 7, 2006; accepted May 18, 2006.
Address correspondence to Wael S. I. Abou-Elmagd, Ain Shams University, Chemistry
Department, Faculty of Science, Abassia, Cairo, Egypt. E-mail: waelmagd97@yahoo.com
85

86
A. S. A. Youssef et al.
SCHEME 1
In this investigation, it was thought that the presence of the
phenylthio group at position 3 might exert a field effect, retarding the
approach of the nucleophile (base). This would make an abstraction of a
proton from position-3 difficult, and therefore, the ring opening should
be the preferred route.
RESULTS AND DISCUSSION
The starring materials for this study, 3-phenylthio-5-aryl-2(3H)-
furanones 4, were prepared from 2-phenylthio-3-aroylpropionic acids
3 (obtained from an addition of thiophenol to 3-aroylacrylic acids)10 by
a ring closure using the procedure previously described by one of us
(Scheme 2).11
SCHEME 2
The structure of furanones was inferred from analytical as well as
spectral data (cf. Table I). IR spectra of these products showed an ab-
sorption band at 1773 cm−1 characteristic of the five-membered lactone
1
carbonyl group. H NMR spectra of 4 showed characteristic signals of
the methine, olefinic, and aromatic protons.
Benzylamine reacted with furanones 4; the product obtained was
found to depend mainly on the reaction conditions. Thus, when the
reaction was carried out in ethanol at r.t. or in refluxing benzene for
1 h, the open-chain benzylamides 5 were obtained.
On the other hand, refluxing the reaction mixture in benzene for
3 h afforded the corresponding 2(3H)-pyrrolones 6. The latter products
were also obtained by a ring closure of the amides 5 using an HCl/AcOH
mixture as a cyclizing agent.
It was of interest to the authors to convert amides 5 into the corre-
sponding isothiazolone derivatives 7 by the action of thionyl chloride at

Conversion of 5-Aryl-3-phenylthio-2(3H)-furanones
87
TABLE I Infrared (IR) and 1H NMR (300 MHz) Spectral Data of
Furanones 4
IR (ν max)
(KBr) cm−1
No.
νC=O
1H NMR (DMSO-d6)
4a
1773
δ = 3.73 (d, 1, CH, J = 1.36 Hz), 6.72 (d, 1, CH, J= 1.56 Hz),
7.20–7.53 (m, 10, ArH)
4b
4c
1772
1773
δ = 3.35 (d, 1, CH, J = 1.30 Hz), 6.80 (d, 1, CH, J= 1.56 Hz),
7.35–7.50 (m, 9, ArH)
δ = 3.30 (d, 1, CH, J = 1.30 Hz), 3.70 (s, 3, OCH3), 6.82 (d, 1, CH,
J= 1.42 Hz), 7.32–7.60 ( m, 9, ArH)
r.t. Debenzoylation of the latter products 7a–c was affected by refluxing
with solid NaOH to give the isothiazolone derivative 7d.
Structures of the products 5,6, and 7 were elucidated from analytical
and spectral data (cf. Table II). The foregoing reactions are represented
by Scheme 3.
SCHEME 3 Reagents and conditions: (i) benzylamine in ethanol at r.t. or
benzene/reflux for 1 h, (ii) benzylamine in benzene/reflux for 3 h, (iii) HCl/AcOH
reflux 1 h, (iv) thionyl chloride at r.t.
Acid hydrazides represent a suitable functionality for obtaining a
wide variety of biologically important heterocyclic systems. Dihydropy-
ridazinones are known to have diverse pharmacological activities, e.g.,

88
A. S. A. Youssef et al.
TABLE II Infrared (IR) and 1H NMR (300 MHz) Spectral Data of 5, 6,
and 7
IR (ν max)
KBr (cm−1
)
No.
νNH
νC=O
1H NMR (DMSO-d6)
5a
3300
1702
1665
δ = 3.16(d, 2, CH2CO, J = 7.2 Hz), 4.10(ABq, 2, N-CH2), 4.56(t,
1, CH, J= 7.2 Hz), 7.15–7.50 (m, 15, ArH), 8.50(br.s, NH,
exchangeable)
5b
3350
1702
1665
δ = 3.20(d, 2, CH2CO, J = 7.0 Hz), 4.15(ABq, 2, N-CH2), 4.56(t,
1, CH, J = 7.0 Hz), 7.10–7.63 (m, 14, ArH), 8.35(br.s, NH,
exchangeable)
5c
6a
3330
—
1705
1675
1650
δ = 3.80(ABq, 2, N-CH2), 4.82 (d, 1, CH, J=
6.0 Hz), 6.59(d, 1, CH, J= 6.0 Hz), 7.51–8.12 (m, 15, ArH)
6b
6c
—
—
1635
1639
δ = 3.80(ABq, 2, N-CH2), 3.95 (s, 3, OCH3), 4.84 (d, 1, CH, J=
6.0 Hz), 6.50 (d, 1, CH, J=
6.0 Hz), 7.50–8.50 (m, 14, ArH)
7a
7b
7c
—
—
—
1688
1690
1687
δ = 3.95( s, 2,N CH2), 7.25–7.55 (m, 15, ArH)
δ = 3.95(s, 3, OCH3), 4.05 (s, 2,N CH2), 7.20–7.55 (m, 14,
ArH)
7d
—
1650
δ = 3.95( s, 2,N CH2), 6.62 (s, 1, CH), 7.25–7.50, (m, 10,
ArH)
antihypertensive,12 analgesic, and antiinflammatory activities.13 1,3,4-
oxadiazoles were reported to have carcinostatic activity against sev-
eral types of tumors14 and antiarrhythmic15 and anticholesterolsmic16
activities. Also 1,2,4-triazoles display some biological activities, such
as an inhibition of cholinesterase,17 interference with mitosis,18 and
reversible denaturation of serum proteins.19 Since this investigation
aims at converting 2(3H)-furanone derivatives 4 into other heterocyclic
systems of biological importance, we believe that the key step is the
conversion of 4 into the corresponding acid hydrazides.
Thus, the furanone 4 reacted with hydrazine hydrate in ethanol at r.t.
to give 3-aroyl-2-phenylthiopropionic acid hydrazides 8. The infrared
spectra of these hydrazides (cf. Table III) showed absorption bands
characteristic of the NH and amide C O groups at 3200–3220 cm−1
and 1670–1690cm−1, respectively. Furthermore, the 1H NMR spec-
trum of 8a showed signals characteristic of the different protons (cf.
Table III).

89

90

Conversion of 5-Aryl-3-phenylthio-2(3H)-furanones
91
Hydrazides 8 were utilized for the synthesis of the following heterocyclic
compounds (cf. Scheme 4):
SCHEME 4 Regents and conditions: (i) Hydrazine hydrate/ethanol r.t.;
(ii) HCl/AcOH reflux 1 h; (iii) PhCOCl/benzene reflux 2 h; (iv) KNCO/H2O r.t.
3 h; (v) ClꢀNꢁH3 NHCONH2/AcONA (1.1 mol) ethanol, reflux 1 h; (vi) HCl/AcOH
reflux 1 h; (vii) POCl3/reflux 20 min; (viii) 2 N NaOH/reflux 2 h.
1. Pyridazinone derivatives 9 were obtained by a ring closure of the
hydrazides 8 using an HCl/AcOH mixture as a cyclizing agent. The
infrared spectra of these compounds (cf. Table III) showed an ab-
sorption band characteristic of the NH and amide C O groups at
3245–3290 cm−1 and 1630–1642 cm−1, respectively. Furthermore,
1
the H NMR spectrum of 9a showed signals characteristic of the
different protons (cf. Table III).

92
A. S. A. Youssef et al.
2. 1-aroylpyridazinones 11 were synthesized from hydrazides 8 by two
steps: (i) hydrazides 8 were converted by the action of benzoyl chlo-
ride into the corresponding diaroylhydrazines 10−, and (ii) a ring
closure of the latter products using HCl/AcOH afforded pyridazi-
nones 11. The infrared spectra of compounds 10 (cf. Table III) showed
absorption bands characteristic of the NH and C O groups at 3350–
3400 cm−1 and 1659–1710 cm−1, respectively. Furthermore, the 1H
NMR spectrum of 10a and b showed signals characteristic of the
different protons (cf. Table III).
3. The infrared spectra of compounds 11 (cf. Table III) showed absorp-
tion bands characteristic of the NH and amide C O groups at 3320–
3324 cm−1 and 1630–1635 cm−1, respectively. Furthermore, the
1H NMR spectrum of 11a and c showed signals characteristic of
the different protons (cf. Table III).
4. 1,3,4-oxadiazoles 13 were obtained by a ring closure of diaroylhy-
drazines using phosphorus oxychloride. Infrared spectra of com-
pounds 13 (cf. Table III) showed absorption bands characteristic
of the C N and C O groups at 1600–1605 cm−1, and 1670–1685
cm−1, respectively. Furthermore, the 1H NMR spectrum of 13a and b
showed signals characteristic of the different protons (cf. Table III).
5. 1,2,4-triazolone derivatives 14 were obtained from hydrazides by
two steps: (i) hydrazides 8 were reacted with pot. isocyanate to give
the corresponding semicarbazide derivatives 12. The infrared spec-
tra of compounds 12 (cf. Table III) showed absorption bands char-
acteristic of NH and C O groups at 3356–3362 cm−1 and 1675–
1710 cm−1, respectively. Furthermore, the 1H NMR spectrum of 12a
and b showed signals characteristic of the different protons (cf. Table
III). The latter products were also obtained by a ring opening of fu-
ranones 4 by semicarbazide in refluxing ethanol. (ii) Semicarbazides
12 were cyclized by means of sodium hydroxide to give triazolones
14. The structures of compounds 14 were elucidated from their an-
alytical as well as spectral data. Infrared spectra of compounds 14
(cf. Table III) showed absorption bands characteristic of NH and
C O groups at 3300–3329 cm−1 and 1675–1680 cm−1, respectively.
1
Furthermore, the H NMR spectrum of 14a and c showed signals
characteristic of the different protons (cf. Table III).
EXPERIMENTAL
Melting points were measured on an electrothermal melting-point ap-
paratus and are uncorrected. Elemental analyses were carried out at
the Micro-Analytical Unit, Cairo University, Giza. IR spectra were mea-
sured on a Unicam SP-1200 spectrophotometer using the KBr-wafer

Conversion of 5-Aryl-3-phenylthio-2(3H)-furanones
93
1
technique. H NMR spectra were measured in DMSO-d6 on a varian
plus instrument (300 MHz).
The Preparation of 2-Phenylthio-3-aroylpropionic Acids (3a–c)
These compounds were prepared according to the procedure described
by previous investigators.10
The Preparation of 3-Phenylthio-5-aryl-2(3H) Furanones (4a–c)
A mixture of 2-phenylthio-3-aroylpropionic acids (3a–c)10 (0.1 mol) and
acetic anhydride (27 mL, 0.3 mol) was heated under reflux for 20 min.
The reaction mixture was cooled, poured onto ice, and filtered off, and
the product was recry stallized from a suitable solvent to give (4a–c)
(cf. Table IV).
The Reaction of 3-Phenylthio-5-aryl-2(3H)-furanones (4a–c)
with Benzylamine
To a solution of the furanones (4a–c) (0.01 mol) in benzene or ethanol
(20 mL), benzylamine (1.1 mL, 0.01 mol) was added. The reaction mix-
ture was refluxed in benzene at 60◦C for 1 h or left at r.t. for 5 min in
ethanol. The products obtained were shown to be 2-phenylthio-3-aroyl-
N-benzyl-propionamides (5a–c), (cf. Table IV). When the reaction mix-
ture was heated at 100◦C for 3 h, the product obtained was filtered off,
washed with benzene, and recrystallized from the suitable solvent (cf.
Table IV). 1-benzyl-3-phenylthio-5-aryl-2(3H)-pyrrolones (6a–c) were
obtained.
The Conversion of Amides (5a–c) into Isothiazolones (7a–c)
A mixture of N-benzylamide derivatives (5a–c) (0.001 mol) and thionyl
chloride (20 mL, 0.17 mol) was stirred at r.t. for 24 h. The excess thionyl
chloride then was evaporated under vacuum. The solid obtained was
filtered off and recrystallized from a suitable solvent (cf. Table IV) to
give 2-benzyl-4-phenylthio-5-aroyl-3 (2H)-isothiazolones (7a–c).
Debenzoylation of (7a–c)
A mixture of (7a–c) (0.01 mol) and solid NaOH (0.1 g, 0.0025 mol)
in 20 mL of benzene was stirred at r.t. for 1 h. When a fading of the
initial yellowish color was observed, the benzene layer was separated
and concentrated under vacuum to give a solid residue, which was

94
A. S. A. Youssef et al.
Table IV Physical and Analytical Data of Compounds 4–14
(Calcd/Found) %
M.P. ◦
C
No.
(solvent)
Yield %
40
C
H
N
S
4a
120–122
(ethanol)
160–163
(ethanol)
140–141
(ethanol)
145–147
(ethanol)
190–191
(ethanol)
165–166
(ethanol)
130–132
(ethanol)
160–162
(ethanol)
140–142
(ethanol)
250–252
(ethanol)
230–233
(ethanol)
257–258
(ethanol)
195–197
(ethanol)
150–153
(benzene)
185–186
(benzene)
165–166
(benzene)
145–146
71.64
71.60
63.47
63.42
68.46
68.69
73.60
73.50
67.40
67.35
71.11
70.95
77.31
77.20
70.50
70.45
74.42
74.39
68.49
68.67
63.09
63.216
66.51
66.60
64.21
64.35
64.00
64.12
57.40
57.57
61.82
61.80
68.09
68.15
60.66
60.78
65.38
65.50
68.32
68.35
62.94
62.89
66.36
66.34
4.48
4.48
3.64
3.60
4.70
4.65
5.60
5.60
4.88
4.86
5.68
5.67
5.32
5.30
4.60
4.62
5.43
5.46
4.22
4.23
3.66
3.69
4.39
4.38
4.35
4.33
5.33
5.35
4.48
4.48
5.45
5.43
4.96
4.97
4.11
4.10
5.13
5.13
4.95
4.93
4.33
4.31
5.07
5.04
—
11.94
11.89
10.58
10.56
10.74
10.69
8.53
8.50
7.80
7.80
7.90
7.87
8.96
8.95
8.17
8.15
8.27
8.24
15.88
15.85
14.63
14.60
14.78
14.77
21.40
21.37
10.67
10.65
9.57
954
9.69
9.65
11.35
11.33
10.11
10.10
10.26
10.25
7.92
4b
4c
50
25
65
62
55
75
70
72
40
35
40
45
72
75
70
55
45
50
40
45
35
—
—
5a
5b
5c
3.73
3.70
3.42
3.40
3.46
3.44
3.92
3.88
3.58
3.64
3.62
3.60
3.47
3.54
3.20
3.31
3.23
3.21
4.68
4.68
9.33
9.50
8.37
8.40
8.48
8.42
9.93
9.97
8.85
8.89
8.97
8.95
6.93
6.90
6.39
6.38
6.45
6.46
6a
6b
6c
7a
7b
7c
7d
8a
8b
8c
9a
9b
9c
(ethanol)
156–159
(ethanol)
183–185
(ethanol)
250–251
10a
10b
10c
(benzene/ethanol)
258–259
(benzene/ethanol)
265–266
7.90
7.29
7.27
7.37
(benzene/ethanol)
7.35
(Continued on next page)

Conversion of 5-Aryl-3-phenylthio-2(3H)-furanones
95
Table IV Physical and Analytical Data of Compounds 4–14
(Continued)
(Calcd/Found) %
M.P. ◦C
No.
(solvent)
Yield %
C
H
N
S
11a
190–192
(ethanol)
178–179
(ethanol)
192–193
30
71.50
71.56
65.64
65.69
69.23
69.20
59.48
59.47
54.01
54.09
57.91
57.96
71.50
71.52
65.64
65.66
69.23
69.20
62.77
62.73
56.75
56.69
60.85
60.82
4.66
4.65
4.04
3.97
4.81
4.89
4.96
4.94
4.24
4.25
5.09
5.07
4.66
4.62
4.04
4.06
4.81
4.80
4.92
4.90
4.17
4.15
5.07
5.07
7.25
7.20
6.66
6.61
6.73
8.29
8.28
7.61
7.64
7.69
7.65
9.33
9.30
8.48
8.46
8.58
8.55
8.29
8.28
7.61
7.60
7.69
7.69
9.85
9.84
8.90
8.92
9.01
9.00
11b
11c
12a
12b
12c
13a
13b
13c
14a
14b
14c
35
45
35
50
40
50
54
50
52
65
50
(ethanol)
110–112
6.79
12.24
12.20
11.13
11.11
11.26
11.26
7.25
7.26
6.66
6.64
6.73
(benzene/ethanol)
125–126
(benzene/ethanol)
130–133
(benzene/ethanol)
180–181
(ethanol)
175–177
(ethanol)
185–186
(ethanol)
219–120
( ethanol)
213–114
(ethanol)
6.70
12.92
12.95
11.68
11.67
11.83
11.80
225–126
(ethanol)
crystallized from ethanol (cf. Table IV) to give 2-benzyl-4-phenylthio-
3(2H)-isothiazolone (7d).
The Reaction of 3-Phenylthio-5-aryl-2(3H)-furanones (4a–c)
with Hydrazine Hydrate
To a solution of furanones (4a–c) (1 mol) in ethanol (20 mL), hydrazine
hydrate (35.5 mL, 1.1 mol) was added at r.t. for 5 min. The product
obtained was filtered off and washed with ethanol, and the product
was shown to be 2-phenylthio-3-aroylpropionic acid hydrazides (8a–c)
(cf. Table IV). When the reaction mixture was refluxed in ethanol, the
product was shown to be 6-aryl-4-phenylthio-4,5-dihydropyridazin-3-
(2H)-one derivatives (9a–c), which were recrystallized from a suitable
solvent (cf. Table IV).

96
A. S. A. Youssef et al.
The Reaction of Hydrazides (8a–c) with Potassium Isocyanate
A solution of potassium isocyanate (1.78 g, 0.02 mol) in water (10 mL)
was added dropwise with stirring at 0◦C to a solution of hydrazide
derivative (8a–c) (0.02 mol) in an acetic acid–water (1:1) mixture. The
reaction mixture was stirred at r.t. for 3 h. The product obtained was fil-
tered off, washed thoroughly with water, and finally recrystallized from
a suitable solvent (cf. Table IV) to give 2-phenylthio-3-aroylpropionic
acid semicarbazides (12a–c).
The same semicarbazide derivatives (12a–c) were also obtained from
heating a solution of 2(3H)-furanones (4a–c) (0.01 mol) in ethanol
(30 mL) and a mixture of semicarbazide hydrochloride (1.12 g, 0.01 mol),
and anhydrous sodium acetate (0.82 g, 0.01 mol) under reflux at 70◦C
for 1 h. The solid was obtained, filtered off, and recrystallized from a
suitable solvent (cf. Table IV). The products obtained were identical in
all respects (m.p., mixed m.p., and TLC) with the previously discussed
products obtained from the reaction between hydrazides (8a–c) and
potassium isocyanate.
The Reaction of Hydrazide (8a–c) with Benzoyl Chloride
To a solution of hydrazide (8a–c) (0.01 mol) in 50 mL of benzene, dry
benzoyl chloride (1.5 mL, 0.01 mol) was added. The reaction mixture
was heated under reflux for 2 h. The solvent was distilled off under
reduced pressure. The yellow solid obtained was washed thoroughly
with water, drained, and recrystallized from the suitable solvent (cf.
Table IV) to give 1-benzoyl-2-[α-phenylthio-β-aroyl] propionyl hy-
drazines (10a–c).
Ring Closure of Compounds (5a–c) and (8a–c)
A solution of (5a–c) or (8a–c) (1 g) in a mixture of (HCl–CH3COOH)
(1:1) (30 mL) or ethanol (30 mL) was heated under reflux for 1 h and then
left to cool. The solid obtained was filtered off, washed with water, and
recrystallized from the suitable solvent (cf. Table IV) to give 1-benzyl-
3-phenylthio-5-aryl-2(3H)-pyrrolone (6a–c) in the case of (5a–c) and
6-aryl-4-phenylthio-4,5-dihdropyridazin-3(2H)-ones (9a–c) in the case
of (8a–c) (cf. Table IV).
Ring Closure of Diaroylhydrazine (10a–c)
Phosphorus oxychloride (10 mL, 0.065 mol) was added dropwise to 1g
of the diaroylhydrazine (10a–c). The reaction mixture was refluxed for

Conversion of 5-Aryl-3-phenylthio-2(3H)-furanones
97
20 min, left to cool, and poured onto crushed ice. The solid obtained was
filtered off, washed with water, and recrystllized from a suitable sol-
vent (cf.Table IV) to give 2-aryl-5-[α-phenylthio-β-benzoyl] ethyl-1,3,5-
oxadiazoles (13a–c).
Ring Closure of the Semicarbazide Derivatives
A solution of 2 N NaOH (40 mL, 0.08 mol) was added to the semicar-
bazide derivatives (12a–c) (0.01 mol). The reaction mixture was re-
fluxed for 2 h, filtered while hot, acidified with hydrochloric acid, and
diluted with 60 mL of water. The solid formed was separated out, fil-
tered off, washed with water, and recystallized from a suitable solvent
(cf. Table IV) to give 3-(α-phenylthio-β-aroyl) ethyl-4,5-dihydro-1,2,4-
triazol-5-ones ( 14a–c).
REFERENCES
[1] R. Filler and L. M. Hebron, J. Am. Chem. Soc., 81, 391 (1959).
[2] A. I. Hashem, J. Prak.Chem, 321, 516 (1979).
[3] A. I. Hashem and M. E. Shaban, J. Prak. Chem., 323, 164 (1981).
[4] A. S. Hamad and A. I. Hashem, J. Heterocycl. Chem., 39, 13255 (2002).
[5] S. M. El-Kousy, A. I. Hashem, A. El-Torgoman, and G. M. Salama, Affindad LX, 530,
1925 (2003).
[6] S. Yassin , A. H. Abd El-Aleem, I. E .Elsayed, and A. I. Hashem, Collect. Czech.
Chem.Commum., 58, 1925 (1993).
[7] A. S. H. El-gazwy, M. Y. Zaki, N. N. Eid, and A. I. Hashem, Heteroatom Chem., 14,
570 (2003).
[8] S. Tassin, A. H. Abd El-Aleem, I. E. El-Sayed, and A. I. Hashem, Rev. Roum. Chem.,
41, 989 (1996).
[9] H. A. Derbala, A. S. Hamad, W. A. El-Sayed, and A. I. Hashem, Phosphorus, Sulfur,
and Silicon, 175, 153 (2001).
[10] A. Sammour and M. El-Hashash, J. Prakt. Chem., 314, 906 (1972).
[11] M. A. Ahmed, A. I. Hashem, and N. Iskander, Rev. Roum. Chem., 38, 79 (1993).
[12] M. V. Curran, J. Med. Chem., 17, 273 (1974).
[13] G. Nannini, G. Biasoli, E. Perrone, A. Forgine, A. Buttinoni, and M. Ferrari, Eur. J.
Med. Chem. Chim. Ther., 14, 53 (1979).
[14] J. Cojocorius, Z. Cojocorius, and C. Niester, Rev. Chim., 28, 15 (1977).
[15] D. Binder and H. Ferber, Eur. Pat., 19, 173 (1987), Chem. Abstr., 108, 585 (1988).
[16] H. Ferres, A. W. Tyrrell, and G. R.- Geen, Drugs Exp. Clin. Res., 52, 964 (1982),
Chem. Abstr., 97, 163012x (1982).
[17] J. P. Polya, Nature (London), 176, 1175 (1955).
[18] W. D., Jackson and J. P. Polya, Aust. J. Sci., 13, 149 (1951).
[19] P. Dunn, E. A. Parkes, and J. P. Polya, Aust. J. Exp. Bvol. Med. Sci., 22, 2220 (1952).