Reactions of hydrazonoyl halides 561: Synthesis and reactions of 1-bromo-2-(5-chloro-benzofuranyl)ethanedione-1-phenylhydrazone

Article abstract of DOI:10.1080/10426500701640876

2,3-Dihydro-1,3,4-thiadiazoles and triazolino[4,3-a]pyrimidines containing benzofuran moiety were prepared from reaction of 1-bromo-2-(5- chlorobenzofuranyl) ethanedione-1-phenylhydrazone with each of potassium thiocyanate, alkyl carbodithioates and pyrmidine-2-thiones. All newly synthesized were confirmed by elemental analysis, spectral data, and alternative route synthesis whenever possible. Copyright Taylor & Francis Group, LLC.

Full text of DOI:10.1080/10426500701640876

This article was downloaded by: [Anadolu University]
On: 26 December 2014, At: 22:30
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
Reactions of Hydrazonoyl
Halides 561: Synthesis
and Reactions of 1-
Bromo-2-(5-chloro-
benzofuranyl)ethanedione-1-
phenylhydrazone
Abdou O. Abdelhamid a , Ahmed H El-Ghandour b &
Ahmed A.M. El-Reedy b
a Department of Chemistry, Faculty of Science ,
Cairo University , Giza, A. R., Egypt
b Department of Chemistry, Faculty of Science , Ben-
Suef University , Ben-Suef, A. R., Egypt
Published online: 09 May 2008.
To cite this article: Abdou O. Abdelhamid , Ahmed H El-Ghandour & Ahmed
A.M. El-Reedy (2008) Reactions of Hydrazonoyl Halides 561: Synthesis and
Reactions of 1-Bromo-2-(5-chloro-benzofuranyl)ethanedione-1-phenylhydrazone,
Phosphorus, Sulfur, and Silicon and the Related Elements, 183:5, 1272-1284, DOI:
10.1080/10426500701640876
To link to this article: http://dx.doi.org/10.1080/10426500701640876
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, 183:1272–1284, 2008
Copyright © Taylor & Francis Group, LLC
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426500701640876
Reactions of Hydrazonoyl Halides 561: Synthesis
and Reactions of 1-Bromo-2-(5-chloro-
benzofuranyl)ethanedione-1-phenylhydrazone
Abdou O. Abdelhamid,1 Ahmed H El-Ghandour,2
and Ahmed A. M. El-Reedy2
1Department of Chemistry, Faculty of Science, Cairo University,
Giza, A. R., Egypt
2Department of Chemistry, Faculty of Science, Ben-Suef University,
Ben-Suef, A. R., Egypt
2,3-Dihydro-1,3,4-thiadiazoles and triazolino[4,3-a]pyrimidines containing ben-
zofuran moiety were prepared from reaction of 1-bromo-2-(5-chlorobenzofuranyl)
ethanedione-1-phenylhydrazone with each of potassium thiocyanate, alkyl carbod-
ithioates and pyrmidine-2-thiones. All newly synthesized were confirmed by elemen-
tal analysis, spectral data, and alternative route synthesis whenever possible.
Keywords 1,3-dipolar cycloaddition; 2,3-Dihydro-1,3,4-thiadiazoles; hydrazonoyl
halides; triazolino[4,3-a]pyrimidines
INTRODUCTION
Hydrazonoyl halides have emerged as an important class of interme-
diates particularly for the synthesis of heterocyclic compounds.1−7 The
interesting pharmacological properties of furan derivatives,8 in rela-
tion to various changes in the structures of these compounds, are worth
studying in order to synthesize less toxic and more potent drugs. Thus,
present investigation deals with the synthesis of some new 2,3-dihydro-
1,3,4-thiadiazoles and triazolino[4,3-a]pyrimidines containing benzofu-
ran moiety.
Received 29 June 2007; accepted 30 July 2007.
Address correspondence to Abdou O. Abdelhamid, Department of Chemistry, Faculty
of Science, Cairo University, Giza 12613, A. R., Egypt. E-mail: abdou abdelhamid@yahoo.
com
1272

Reactions of Hydrazonoyl Halides 56
1273
RESULTS AND DISCUSSION
Treatment of 5-chlorobenzofuranyl-2-oxoethylsulfonium bromide (3)9
with N-nitrosoacetanilide (4)10 in ethanol at room temperature to
give 1-bromo-2-(5-chlorobenzofuranyl)ethanedione-1-phenylhydrazone
(6). Structure 6 was established by elemental analysis, spectral
data, and chemical transformation. Thus, treatment of 6 with potas-
sium thiocyanate in ethanol at room temperature afforded product
which gave analytical and spectral in accord with their formation
as: 5-chlorobenzo[d]furan-2-yl-2-imino-3-phenyl(1,3,4-thiadiazolin-5-
yl)ketone (8). IR spectrum of 8 revealed the absence bands at 2156
(SCN) and showed bands at 3316 (NH), 1640 (CO conjugated). Its
1HNMR spectrum showed signals at δ = 7.43–7.55 (m, 5H), 7.59–7.88
(m, 4H), and 8.08 (s, 1H). Upon shaking with D2O a new signal singlet
appeared at δ = 4.55 assignable to DOH proton and multiplicity signals
at δ = 7.43–8.00 ppm. Compound 8 was authentically sample by the
reaction of [2-(5-chlorobenzo[d]furan-2-yl)-2-oxoethyl]thiocarbonitrile
(9), with benzenediazonium chloride in ethanolic sodium acetate solu-
tion (Scheme 1). Such results indicate that both the azo coupling of 9 and
the reaction of 6 with potassium thiocyanate proceed through one com-
mon intermediate. The latter is undoubtedly the hydrazone 7, which
cyclizes readily under the reaction conditions to give 8 (Scheme 1).
More evidence on the structure 8 can be come from the follow-
ing chemical transformation. Thus, acetylation of 8 with acetic an-
hydride to yield the corresponding 1-aza-1-5-[(5-chlorobenzo[d]furan-
1
2-yl)carbonyl]-3-phenyl](1,3,4-thiadiazolin-2-ylidene))acetone (10). H
NMR spectrum of 10 showed signals at δ = 2.38 (s, 3H), 7.26–7.61
(m, 5H), 7.73–7.80 (m, 3H), and 8.20 (s, 1H). Nitrosation of 8 with
sodium nitrite in acetic acid solution to give 2-(azanitrosomethylene)-3-
phenyl(1,3,4-thiadiazolin-5-yl)-5-chlorobenzo-[d]furan-2-ylketone (11).
The IR spectrum of 11 showed no band due to NH, but con-
tained common bands at 1646 (CO) and 1490 (NO). Compound 11a
decomposed to 5-[(5-chlorobenzo[d]furan-2-yl)carbonyl]-3-phenyl-1,3,4-
thiadiazolin-2-one (12a) upon boiling in xylene solution. The IR spec-
trum of 12 revealed two absorption bands near 1692 and 1645 cm−1
.
Compound 6 reacted with methyl phenylthiocarbamate11 (13) in
ethanolic triethylamine solution to give 2-(azaphenylmethylene)-3-
phenyl(1,3,4-thiadiazolin-5-yl)-5-chlorobenzo[d]furan-2-yl ketone (16)
(Scheme 2). Structure 16 was confirmed on the basis of spectral data
and elemental analysis. Thus, 1H NMR spectrum of 16 showed signals
at δ = 6.46–7.01 (m, 5H) and 7.20–7.59 (m, 9H).
In the light of the foregoing results, the mechanism outlined in
scheme 2 seems to be the most plausible pathway for the formation

1274
A. O. Abdelhamid et al.
SCHEME 1
of 16 from the reaction of the 6 with 13. The reaction involves ini-
tial formation of thiohydrazonate 14, which undergoes intermolecu-
lar cyclization as soon as it is formed to yield the intermediate 15 or
via 1,3-dipolar cycloaddition of nitrilimine 17, (which prepared in situ
from 6 with triethylamine) to C S double bond of 13. The formation
of 14 and 15 are similar to the reaction of hydrazonoyl chloride with
1-phenyl-1,4-dihydrotetrazole-5-thione12 and 5-phenyl-1,3,4-thiadia-
zole-2(3H)-thione13.

Reactions of Hydrazonoyl Halides 56
1275
SCHEME 2
Analogously,
6
reacted with each of 3-{aza-[(methylthioxo-
methyl)-amino]methylene}indoline-2-one14 and 3-{aza-[(methylthioxo-
methylamino]-methylene}indan-1,3-dione15 to give 3-(1,2-diaza-2-
{5-[(5-chlorobenzo[d]-furan-2-yl)carbonyl]-3-phenyl-(1,3,4-thiadiazo-
lin-2-ylidene))-ethylidine}indolin-2-one (19) and 2-(1,2-diaza- 2-{5-
[(5-chlorobenzo[d]furan-2-yl)carbonyl]-3-phenyl-(1,3,4-thiadiazolin-2-
ylidene))ethylidine}indane-1,3-dione (20), respectively (Scheme 3).
SCHEME 3
Also, treatment of [(1-aza-phenylvinyl)amino]methylthiomethane-
1-thione 21a16 with 6 in ethanolic triethylamine at room tem-
perature, gave 2-(1,2-diaza-3-phenylprop-2-enylidene)-3-phenyl-(1,3,4-
thiadiazolin-5-yl)-5-chlorobenzo[d]furan-2-ylketone 25a (Scheme 4).
Structure 25a was confirmed by elemental analysis, spectral data, and
1
alternative route synthesis. H NMR spectra of 25a showed signals
at δ = 6.46–7.30 (m, 10H), 7.42–7.59 (m, 3H), and 8.10 (s, 1H). Thus,

1276
A. O. Abdelhamid et al.
SCHEME 4
treatment of 6 with 22a in ethanolic triethylamine gave product iden-
tical in all aspects (mp., mixed mp., and spectra) with 25a.
Similarly, 6 reacted with other alkyl carbodithioates17−19 21–22
(b-j) in ethanol containing triethylamine to afford 2,3-dihydro-1,3,4-
thiadiazoles 25(b–j), respectively (Scheme 4).
Also, treatment of 6 with the appropriate pyrimidine-2-thiones 26a-
d20 in boiling chloroform gave triazolino[4,3-a]pyrimidines in a good
yields 30a-d, respectively (Scheme 5). Structure of 30 was elucidated
on the basis elemental analysis, spectral data, and alternative synthesis
route.
1
Thus, H NMR spectrum of 30a showed signals at δ = 1.23 (t, 3H),
2.56 (s, 3H), 4.09 (q, 2H), 7.05 (s, 1H), 7.16–7.25 (m, 3H), 7.44–7.72
(m, 8H), 8.05 (s, 1H), and 8.24 (d, 2H). Its IR spectrum revealed bands
at 1702 (CO ester), 1650 (CO conjugated) and 1615 (C=N). In addi-
tion, compound 30a was obtained from the reaction of ethyl 6-methy-2-
methylthio-4-phenyl-3,4-dihydropyrimidine-5-carboxylate20 31a with
6 in boiling sodium ethoxide solution. The mechanism outlined in
scheme 5 seems to be the most plausible pathway for the formation
of 30 from the reaction of 6 with the appropriate 26a–d or 31a–d. Two
possible pathways can account for the formation 30: 1)- 1,3-addition of
the thiol tautomer 26 to the nitrilium imide 17 to give the thiohydra-
zonate ester 27 which undergoes nucleophilic cyclization to yield spiro
compounds 28. The latter ring open to 29 which cyclized to yield 30
by loss hydrogen sulfide; and 2)- 1,3-cycloaddition of nitrilium imide to

Reactions of Hydrazonoyl Halides 56
1277
SCHEME 5
C S double bond of 26 can give directly 31 (Scheme 5). All attempts to
isolate any intermediates are unsuccessful.
Also, 2-acetyl-5-chlorobenzo[d]furan was reacted with methyl
hydrazine carbodithioate21,22 in isopropyl alcohol to give {[1-aza-2-
(5-chlorobenzo[d]furan-2-yl)prop-1-enyl]amino}methylthiomethane-1-
thione 33 (Scheme 6). Structure 33 was confirmed by elemental
analysis, spectral data, and its reaction with hydrazonoyl halides.
Thus, 1H NMR spectrum of 33 showed signals at δ = 2.34 (s, 3H), 2.66
(s, 3H), 7.04–7.57 (m, 4H) and 9.99 (s, br., 1H). Thus, compound 33
reacted with C-ethoxycarbonyl-N-phenyl-hydrazonoyl chloride 34a,
in ethanol containing triethylamine at room temperature to afford
ethyl
2-[1,2-diaza-3-(5-chlorobenzo[d]furan-2-yl)but-2-enylidene]-3-
phenyl-1,3,4-thiadiazolin-5-carboxylate 37a (Scheme 6). Structure 37
was elucidated by elemental analysis, spectral data and alternative
1
method. Thus, H NMR spectrum of 37a showed signals at δ = 1.44

1278
A. O. Abdelhamid et al.
SCHEME 6
(t, 3H), 2.45 (s, 3H), 4.46 (q, 2H) and 7.12–8.09 (m, 9H). Hydrazine
38 reacted with 1 in isopropyl alcohol to give product identical in all
aspects (mp., mixed mp., and spectra) with 37a. Thus, thiodiazoline
3823 reacted with 2-acetyl-5-chlorobenzofuran (1) in 2-propanol to give
product identical in all aspect (mp., mixed mp., and spectra) with 37a.
Similarly, the appropriate hydrazonoyl halides 34b-d and 6 reacted
with carbodithioate 33 in ethanolic triethylamine at room temperature
afforded 2,3-dihydro-1,3,4-thiadiazoles 37b-e, respectively.
EXPERIMENTAL
All melting points were determined on an electrothermal apparatus and
are uncorrected. IR spectra were recorded (KBr discs) on a Shimadzu
1
FT-IR 8201 PC spectrophotometer. H NMR spectra were recorded in
CDCl3 and (CD3)2SO solutions on a Varian Gemini 300 MHz spectrom-
eter and chemical shifts are expressed in δ units using TMS as an in-
ternal reference. Elemental analyses were carried out at the Microan-
alytical Center of the Cairo University.

Reactions of Hydrazonoyl Halides 56
1279
1-(5-Chlorobenzo[d]furan-2-oyl)methane dimethylsulfonium
bromide (3)
A mixture of 2-bromo-1-(5-chlorobenzo[d]furan-2-yl)ethan-1-one (2)
(13.63 g, 50 mmol) and dimethyl sulfide (3.2 g, 50 mmol) in ethanol
( 100 mL) was boiled for 30 min. The reaction mixture was cooled and
diluted with ether (50 mL) for complete precipitation. The crude solid
was collected and recrystallized from ethanol to give 3 (Table I).
3-Aza-2-bromo-1-(5-chlorobenzo[d]furan-2-yl)-3-
(phenylamino)-prop-2-en-1-one (6)
A mixture of sulfonium bromide 3 (16.2 g, 50 mmol) and N-nitroso-
acetanilide (10 g, 60 mmol) in ethanol (100 mL) was stirred for 2 h. The
yellow solid was collected and recrystallized from acetic acid to give 6
(Table I).
[2-(5-chlorobenzeno[d]furan-2-yl)-2-oxoethyl]thiocarbonitrile
(9)
A mixture of 2-bromo-1-(5-chlorobenzo[d]furan-2-yl)ethan-1-one (2)
(1.36 g, 5 mmol) and potassium thiocyanate (0.49 g, 50 mmol) in ethanol
(25 mL) was boiled for 30 min. The resulting solid, which formed af-
ter cooling, was collected, washed with water, and recrystallized from
ethanol to give 9 (Tables I and II).
3-Aryl-5-chlorobenzo[d]furan-2-yl-2-imino-(1,3,4-thiadiazolin-
5-yl)ketone 8a and 8b
Method A
A mixture of 6 (1.88 g, 5 mmol) and potassium thiocyanate (0.58 g,
6 mmol) in ethanol (25 mL) was stirred at room temperature for 3 h.
The resulting solid was collected, washed with water and recrystallized
from ethanol to give 8a (Tables I and II).
Method B
The appropriate arenediazonium chloride (5 mmol) was added
dropwise to a cold solution of ethanol (50 mL), containing a [2-
(5-chlorobenzeno[d]furan-2-yl)-2-oxoethyl]thiocarbonitrile (9) (1.25 g,
5 mmol) and sodium acetate (1.3 g, 10 mmol), while stirring at 0–5◦C.
The resulting solid was collected and recrystallized from ethanol to give
8a and 8b, respectively (Tables I and II).

1280
A. O. Abdelhamid et al.
TABLE I Characterization Data of the Newly Synthesized
Compounds
% Analyses, calcd./found
Compd.
no.
Mp., ◦
solvent
C
Yield %
color
Mol. formula
mol. wt.
C
H
N
S
3
138-40
EtOH
194-6
EtOH
171-3
EtOH
179-82
EtOH
140-1
EtOH
254-5
AcOH
233-5
AcOH
140-3
EtOH
125-7
EtOH
152-4
EtOH
168-70
EtOH
268-71
DMF
> 300
DMF
295-7
DMF
279-80
DMF
257-9
DMF
254-5
DMF
142-5
DMF
253-5
DMF
246-9
DMF
240-2
DMF
233-5
DMF
Yellow
75
Yellow
60
Brown
59
Brown
61
Yellow
70
Brown
75
Yellow
73
Brown
60
Brown
54
Brown
50
Brown
52
Yellow
55
Orange
63
Brown
65
Orange
71
Red
C12H12Br Cl O2S
335.64
42.94
42.88
50.89
50.71
57.39
57.59
58.46
58.62
52.49
52.69
57.36
57.18
58.32
58.49
53.06
53.18
54.21
54.40
57.23
57.42
58.30
58.50
63.96
63.78
60.06
60.20
60.17
60.30
62.81
62.66
56.83
56.66
58.87
59.00
60.07
59.82
63.49
63.66
57.67
57.79
59.68
59.87
60.82
61.00
3.60
3.41
2.67
2.80
2.83
2.60
3.27
3.46
2.40
2.59
3.04
3.19
3.43
3.28
2.36
2.55
2.78
2.62
2.54
2.39
2.99
3.11
3.27
3.44
2.82
3.00
3.69
3.88
3.29
3.45
2.82
3.00
2.92
3.11
3.07
3.22
3.62
3.44
3.16
3.36
3.27
3.10
3.40
3.21
—
—
7.42
7.24
11.81
12.00
11.36
11.51
5.57
9.55
9.37
—
6
C
16H10Br Cl N2O2
377.62
—
8a
C17H10Cl N3O2S
9.01
9.20
8.67
8.85
12.74
12.91
8.06
8.18
7.79
7.59
8.33
8.52
8.04
7.89
8.99
9.10
8.65
8.48
7.42
7.30
6.41
6.56
6.18
6.01
6.99
7.16
13.79
13.59
7.14
7.32
6.97
7.16
6.78
6.58
13.39
13.18
6.93
7.14
6.77
6.91
355.79
C18H12Cl N3O2S
369.82
8b
9
C
11H6Cl N O2S
251.69
5.37
10a
10b
11a
11b
12a
12b
16
C19H12Cl N3O3S
397.83
10.56
10.73
10.20
10.39
14.56
14.39
14.05
14.20
7.85
7.66
7.55
7.70
9.73
C
20H14Cl N3O3S
411.86
C
17H9Cl N4O3S
384.79
C
18H11Cl N4O3S
398.82
C17H9Cl N2O3S
356.78
C
18H11Cl N2O3S
370.81
C
C
C
23H14Cl N3O2S
431.89
25H14Cl N5O3S
499.92
26H19Cl N4O4S
518.97
9.59
19
14.01
13.88
10.80
10.66
12.21
12.40
12.05
12.20
12.48
12.74
15.23
15.41
11.85
11.99
11.70
11.89
12.10
12.28
14.78
14.59
20
25a
25b
25c
25d
25e
25f
25g
25h
C24H15Cl N4O2S
458.92
C22H13Cl N4O2S2
464.94
63
Brown
69
Brown
57
Red
75
Red
72
Brown
56
C
C
C
22H13Cl N4O3S
448.88
23H14Cl N5O2S
459.90
25H17Cl N4O2S
472.94
C
23H15Cl N4O2S2
478.97
C23H15Cl N4O3S
462.90
C24H16Cl N5O2S
473.93
Brown
60
(Continued on next page)

Reactions of Hydrazonoyl Halides 56
1281
TABLE I Characterization Data of the Newly Synthesized
Compounds (Continued)
% Analyses, calcd./found
Compd.
no.
Mp., ◦
solvent
C
Yield %
color
Mol. formula
mol. wt.
C
H
N
S
25i
25j
215-8
AcOH
238-40
DMF
212-5
AcOH
168-9
EtOH
169-72
EtOH
218-21
DMF
172-5
EtOH
169-72
AcOH
240-2
AcOH
200-3
AcOH
203-6
AcOH
272-5
DMF
Yellow
66
Yellow
64
Red
70
Red
72
Red
68
Red
63
Yellow
75
Yellow
74
Orange
65
Yellow
69
Yellow
70
Red
74
C23H19Cl N4O2S
450.94
61.26
61.44
60.48
60.67
66.85
66.99
67.33
67.53
65.44
65.29
62.84
63.00
48.23
48.42
57.21
57.41
61.54
61.71
58.46
58.59
63.49
63.66
59.24
59.44
4.25
4.08
3.92
4.10
4.30
4.11
4.56
4.38
4.43
4.59
3.87
3.70
3.71
3.89
3.89
4.06
3.72
3.57
3.68
3.50
3.62
3.80
2.95
3.15
12.42
12.59
12.82
12.66
10.39
10.19
10.13
10.30
9.85
9.99
9.77
9.94
9.37
7.11
7.31
7.34
7.41
—
C
22H17Cl N4O2S
436.91
30a
30b
30c
30d
33
C
30H23Cl N4O4
538.98
C31H25Cl N4O4
553.00
—
—
—
C
31H25Cl N4O5
569.00
C
30H22Cl2N4O4
573.42
C
12H11Cl N2O S2
298.81
21.46
21.28
7.27
7.40
6.57
6.74
7.80
7.99
6.78
6.98
5.86
6.04
9.18
37a
37b
37c
37d
37e
C
21H17Cl N4O3S
440.90
12.71
12.58
14.35
14.20
13.64
13.48
11.85
11.69
10.23
10.44
C
25H18Cl N5O2S
487.96
C20H15Cl N4O2S
410.87
C
25H17Cl N4O2S
472.947
C
27H16Cl2N4O3S
547.412
3-Aryl-2-(azanitrosomethylene)(1,3,4-thiadiazolin-5-yl)-5-
chlorobenzo[d]furan-2-ylketone 11a,b
A cold saturated solution of sodium nitrite (10 ml) was added dropwise
to the appropriate8a and 8b (1 g) in acetic acid (20 mL) in an ice bath
while stirring. The reaction mixture was stirred for 30 min. The re-
sulting solid was collected, washed with water, and recrystallized from
acetone to give 11a and 11b, respectively (Tables I and II).
3-Aryl-5-[(5-chlorobenzo[d]furan-2-yl)carbonyl-1,3,4-
thiadiazolin-2-one 12a,b
A solution of the appropriate 11a or 11b (0.5 g) in xylene (20 mL) was
boiled for 15 min and then the solvent was evaporated under reduced
pressure. The residue oil was triturated with petroleum ether (40–
60◦C) and the solid formed was collected and recrystallized from acetic

1282
A. O. Abdelhamid et al.
TABLE II IR and 1H NMR Spectra of Some Selected Synthesized
Compounds
Compd.
no.
1H NMR (δ ppm)
6
IR: 3245 (NH), 1643 (CO conjugated) 1HNMR: 6.25–7.81 (m, 9H)
and 9.35 (s, 1H)
8b
IR: 3314 (NH), 1643 (CO conjugated) 1HNMR: 2.44 (s, 3H), 6.26–7.71 (m, 8H),
8.06 (s, 1H)
9
10b
IR: 2160 (CN), 1666 (CO) 1HNMR: 4.54 (s, 2H), 7.44–7.72 (m, 4H)
IR: 1645 (CO conjugated) 1HNMR: 2.26 (s, 3H), 2.49 (s, 3H), 7.39–7.80 (m,
7H), 8.20 (s, 1H)
11a
11b
12a
12b
IR: 1645 (CO conjugated) 1HNMR: 6.26–7.71 (m, 9H), 8.06 (s, 1H)
IR: 1645 (CO conjugated) 1HNMR: 2.43 (s, 3H), 6.26–7.71 (m, 8H), 8.06 (s, 1H)
IR: 1692, 1645 (CO) 1HNMR: 6.26–7.71 (m, 9H), 8.06 (s, 1H)
IR: 1692, 1645 (CO) 1HNMR: 2.42 (s, 3H),6.26–7.71 (m, 8H),
8.06 (s, 1H)
25e
25f
25g
25h
30b
1HNMR: 2.50 (s, 3H), 7.26–8.16 (m, 14 H)
1HNMR: 2.46 (s, 3H), 7.05–8.15 (m, 12 H)
1HNMR: 2.40 (s, 3H), 6.50–8.16 (m, 12 H)
1HNMR: 2.59 (s, 3H), 7.26–8.64 (m, 13 H)
1HNMR: 1.23 (t, 3H), 2.21 (s, 3H), 2.55 (s, 3H), 4.08 (q, 2H),
6.98 (s, 1H), 7.01–8.27 (m, 13 H)
30c
30d
33
1HNMR: 1.22 (t, 3H), 2.55 (s, 3H), 3.68 (s, 3H), 4.08 (q, 2H),
6.70 (s, 1H), 6.99–8.27 (m, 13 H)
1HNMR: 1.25 (t, 3H), 2.55 (s, 3H), 4.09 (q, 2H), 7.02 (s, 1H),
7.19–8.27 (m, 13 H)
IR: 3167 (NH), 1605 (C=C) 1HNMR: 2.34 (s, 3H), 2.66 (s, 3H),
7.04–7.57 (m, 4H), 9.99 (s, br., 1H)
37a
37c
IR: 1740 (CO) 1HNMR: 1.46 (t, 3H), 2.34 (s, 3H), 3.21 (q, 2H),
7.12–8.09 (m, 9H)
IR: 11680 (CO) 1HNMR: 2.45 (s, 3H), 2.65 (s, 3H), 7.12–8.09 (m, 9H)
acid to give 1,3,4-thiadiazolinones 12a and 12b, respectively (Tables I
and II).
3-Aryl-1-aza-1-{5-[(5-chlorobenzo[d]furan-2-yl)carbonyl]-(1,3,4-
thiadiazolin-2-ylidene)}acetone 10a,b
A mixture of the appropriate 8a or 8b (1 g) in acetic acid (10 mL) and
acetic anhydride (5 ml) was warmed for 5 min at 70◦C. The reaction
mixture was poured onto ice water (40 mL). The solid was collected and
recrystallized to give theN-acetyl derivatives 10a and 10b, respectively
(Tables I and II).

Reactions of Hydrazonoyl Halides 56
1283
2,3-Dihydro-1,3,4-Thiadiazoles 16, 19–20, and 25a–j
Triethylamine [0.5 g (0.75 ml), 5 mmol] was added dropwise with stir-
ring to a mixture of the appropriate alkyl carbodithioates 13, 17, 18, or
(21-22)a-j (5 mmol) and 6 (1.8 g, 5 mmol) in ethanol (20 mL). The result-
ing solid, which formed after 30 min, was collected and recrystallized
from N, N-dimethylformamide to give 2,3-dihydro-1,3,4-thiadiazoles
16, 19, 20, 25a-j, respectively, in a good yield (Tables I and II).
1,2,4-Triazolo[4,3-a]pyrimidines 30a-d
Method A
An equimolar amount of the hydrazonoyl bromide 6, the appropriate
of pyrimidines 31a–d, and sodium ethoxide (5 mmol) in ethanol (20 mL)
was heated under reflux for 3 h. The reaction mixture was cooled and
the resulting solid was collected and recrystallized from ethanol to give
30a-d, respectively (Tables I and II).
Method B
A mixture of the hydrazonoyl bromide 6 (5 mmol), the appropriate
26a-d (5 mmol) and triethylamine [0.5 g, (0.75 mL), 5 mmol] in chloro-
form (20 mL) containing was refluxed for 10 h. Chloroform was evap-
orated under reduced pressure and the residue solid was crystallized
from ethanol to give products identical in all aspects (mp., mixed mp.,
and spectra) with corresponding products obtained by method A.
{[1-Aza-2-2-(5-chlorobenzo[d]furan-2-yl)prop-1-
en]amino}methyl-thiomethan-1-thion (33)
A mixture of 2-acetyl-5-chlorobenzo[d]furan (1)(0.92 gm, 5 mmol) and
methyl hydraziocarbodithioate (0.66 g, 5 mmol) in 2-propanol (20 mL)
was stirred at room temperature for 2 h. The resulting solid was col-
lected and recrystallized to give 33 (Table I).
2-[1,2-Diaza-3-(5-chlorobenzo[d]furan-2-yl)but-2-enylidene]-3-
phenyl(1,3,4-thiadiazolin-5-yl) 4-Substituted Ketenes 37a-e
Method A
Triethylamine [0.5 g (0.75 ml), 5 mmol] was added dropwise with
stirring to a mixture of the appropriate methyl carbodithioate 33 and
the appropriate hydrazonoyl halides 34a-d or 6 (5 mmol) in ethanol (20
mL). The resulting solid, which formed after 30 min, was collected and

1284
A. O. Abdelhamid et al.
crystallized from N, N-dimethylformamide to afford the corresponding
thiadiazolines 37a-e, respectively (Tables I and II).
Method B
A mixture of thiadiazoline 38 (1.32 g, 5 mmol) and 2-acetyl-5-
chlorobenzofuran (0.92 g, 5 mmol) in 2-propanol (20 mL) was heated
for 10 min then cooled. The resulting solid was collected and recrystal-
lized from acetic acid to give 37a (Tables I and II).
REFERENCES
[1] Part 55: A. O. Abdelhamid, V. B. Baghos, S. H. Doss, and M. M. A. Halim, Phosphorus,
Sulfur, Silicon and Relat. Element., 182, 2843 (2007).
[2] R. Huisgen, R. Garashey, and J. Sauer, The Chemistry of alkenes,, S. Pati,Ed. (Wiley-
Interscience, New York, 1964), Vol. 1, p. 739.
[3] H. Ulrich, The Chemistry of Imidoyl Halides (Plenum Press, New York, 1968) , Chap.
7, p. 173.
[4] R. N. Butler and F. L. Scott, Chem. Ind. (London), 38, 1216 (1970).
[5] A. S. Shawali and C. Pa´rka´nyi, J. Heterocycl. Chem., 17, 833 (1980).
[6] A. S. Shawali, Heterocycles, 20, 2239 (1983).
[7] A. S. Shawali, Chem. Rev., 93, 2731 (1993).
[8] F. M. Dean, Comprehensive Heterocyclic Chemistry, A. R. Katritzky and C. W. Ress,
Eds. (Pergamon Press, Oxford, 1984), Vol., 4, pp. 705–709.
[9] F. Binon, C. Goldenbery, G. Deltour, and E. Gillyns, Chim., Therap, 3, 141 (1966);
Chem. Abstr., 65, 10,549b (1966).
[10] (a) R. M. Cowper and L. H. Davidson, Org. Synthesis Coll., 2, 840 (1943); (b) O.
Fisher, Chem., Ber. 9, 463 (1967).
[11] C. S. Pak, I. Youn, and Y. S. Lee, Synthesis, 969 (1982)
[12] R. Huisgen, R. Garashey, M. Seidal, H. Knupfer, and R. Schmidt, Ann. Chem., 658,
169 (1962).
[13] R. N. Butler, E. P. Ni Bhradaigh and K. J. Fitzgerald, J. Chem. Res., (S)306, (M)1993,
(1948).
[14] Y. P. Kovtun and N. N. Ramanov, Khim., Geterosikt, Soedin, 211 (1985).
[15] A. O. Abdelhamid, S. M. Abdel- Gwad, and S. F. El-Sharnoby, Phosphorus, Sulfur,
177, 2699 (2002).
[16] J. Sandstrom, Arkiv Kemi., 4, 297, 1952; Chem. Abstr., 47, 9271d (1953).
[17] J. Sandstrom, Arkiv Kemi., 9, 225, 1956; Chem. Abstr., 50, 15,516d (1956).
[18] J. Sandstrom, Acta Chem., Scand., 17, 937, 1963; Chem. Abstr., 60, 10,072f (1963).
[19] J. Korosi, Ger. Offen. 1, 934, 809 29 (1970, Jan); Chem. Abstr., 72, 100,334s (1970).
[20] S. M. Sherif, M. M. Yousef, K. M. Mobarak, and A. M. Abdel-Fattah, Tetrahedron,
49, 9561 (1993).
[21] M. Busch and M. Starke, J. Prakt. Chem., 93, 49 (1916).
[22] L. Rubenstein, J. Chem. Soc., 127, 1998 (1925)
[23] H. F. Zohdi, N. M. Rateb, M. M. M. sallam and A. O. Abdelhamid, J. Chem. Res., (S)
742; (M) 3329. (1998).