Novel 1,3-dithiolan-2-ones using sodium α-cyanoketene dithiolates

Article abstract of DOI:10.1080/00397910500449500

A novel and efficient method for the synthesis of 1,3-dithiolan-2-ones using sodium α-cyanoketene dithiolates and monochloroacetic acid as starting components is described. Copyright Taylor & Francis Group, LLC.

Full text of DOI:10.1080/00397910500449500

This article was downloaded by: [University of Utah]
On: 06 May 2013, At: 03:11
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
Synthetic Communications: An International
Journal for Rapid Communication of
Synthetic Organic Chemistry
Publication details, including instructions for authors and subscription
information:
http://www.tandfonline.com/loi/lsyc20
Novel 1,3‐Dithiolan‐2‐ones Using Sodium
α‐Cyanoketene Dithiolates
G. H. Elgemeie a , A. H. Elghandour b , A. M. Elzanaty b & S. A. Ahmed b
a Department of Chemistry, Faculty of Science, Helwan University,
Ain‐Helwan, Cairo, Egypt
b Department of Chemistry, Faculty of Science, Cairo University (Bani Suef
Branch), Bani Suef, Egypt
Published online: 16 Aug 2006.
To cite this article: G. H. Elgemeie , A. H. Elghandour , A. M. Elzanaty & S. A. Ahmed (2006): Novel
1,3‐Dithiolan‐2‐ones Using Sodium α‐Cyanoketene Dithiolates, Synthetic Communications: An International
Journal for Rapid Communication of Synthetic Organic Chemistry, 36:6, 755-764
To link to this article: http://dx.doi.org/10.1080/00397910500449500
PLEASE SCROLL DOWN FOR ARTICLE
Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions
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.
The publisher does not give any warranty express or implied or make any representation that the
contents will be complete or accurate or up to date. The accuracy of any instructions, formulae,
and drug doses should be independently verified with primary sources. The publisher shall not
be liable for any loss, actions, claims, proceedings, demand, or costs or damages whatsoever or
howsoever caused arising directly or indirectly in connection with or arising out of the use of this
material.

Synthetic Communicationsw, 36: 755–764, 2006
Copyright # Taylor & Francis Group, LLC
ISSN 0039-7911 print/1532-2432 online
DOI: 10.1080/00397910500449500
Novel 1,3-Dithiolan-2-ones Using Sodium
a-Cyanoketene Dithiolates
G. H. Elgemeie
Department of Chemistry, Faculty of Science, Helwan University,
Ain-Helwan, Cairo, Egypt
A. H. Elghandour, A. M. Elzanaty, and S. A. Ahmed
Department of Chemistry, Faculty of Science, Cairo University
(Bani Suef Branch), Bani Suef, Egypt
Abstract: A novel and efficient method for the synthesis of 1,3-dithiolan-2-ones using
sodium a-cyanoketene dithiolates and monochloroacetic acid as starting components is
described.
Keywords: a-Cyanoketene dithioacetals, 1,3-dithiolan-2-ones, heterocycles, mono-
chloroacetic acid, sodium a-cyanoketene dithiolates
Recently, we reported an improved method for the preparation of novel a-
cyanoketene S,S-acetals 2 and their conversions to various substituted
methylthio derivatives of pyrrole, pyrazole, pyridine, and pyrimidine.[1] In
an extension of this work, we now report a novel synthesis of functionalized
1,3-dithiolanes using sodium a-cyanoketene dithiolate 3 as versatile
precursors (Scheme 1). Thus, it has been found that substituted acetanilide
derivatives la–d reacted with carbon disulphide in the presence of sodium
ethoxide to give the corresponding sodium a-cyanoketene dithiolates 3. The
latter were alkylated with chloroacetic acid to give the novel mono-
alkylated products 7. The structures of 7 were established on the basis of
1
their elemental analysis and spectral data (IR, MS, H NMR). On reflux in
ethanolic sodium ethoxide compounds 7 undergo cyclization to give the
Received in the USA September 15, 2005
Address correspondence to G. H. Elgemeie, Department of Chemistry, Faculty of
Science, Helwan University, Ain-Helwan, Cairo, Egypt. E-mail: elgemeie@hotmail.com
755

756
G. H. Elgemeie et al.
Scheme 1.
corresponding 1,3-dithiolane derivatives 8. The structure of compounds 8 was
established on the basis of their elemental analysis and spectral data.
Compounds 8 can also be prepared by alkylation of the dithiolate 3 with
ethyl bromoacetate followed by cyclization of the resulting acyclic product

1,3-Dithiolan-2-ones
757
6. Compounds 8 bear an active methylene function adjacent to a carbonyl
group and are expected to react with unsaturated nitriles to give condensed
dithiolane derivatives. Thus, it has been found that dithiolanes 8 reacted
with [bis(methylthio)methylene]malononitrile 9 in refluxing ethanol contain-
ing catalytic amounts of piperidine to give N-aryl-4-methylsulfanyl-2-
pyridones 10a–d and not the expected pyranodithiolane derivatives 13
(Scheme 2). The structures of 10 were established on the basis of their
elemental analysis and spectral data (MS, IR, 1H NMR). Moreover, the
products 10 obtained were shown to be identical to those obtained from our
Scheme 2.

758
G. H. Elgemeie et al.
previously reported reaction of 1 with 9 by their melting points and spectral
data.[2] The formation of 10 from 1 and 9 is assumed to proceed via the inter-
mediacy of 12. The unexpected course of the reaction between dithiolanes 8
and the ketene dithioacetal 9 prompted us to investigate this reaction for the
dithiolanes 8 and the arylmethyenemalononitriles 14 under the same con-
ditions (Scheme 3). Similarly, the N-aryl-2-pyridone products 15 were
obtained, identical to those obtained from the reaction of cyanoacetanilides
1 with arylmethylenemalononitriles 14 (melting points, spectral data)
(Table 1).[3–6] The mechanism of the reaction of 1 and 14 is assumed to
proceed through the formation of the initial adduct 17, which leads to the
product 15 as produced by the reaction of 8 with 14. Although an investigation
of the reaction mechanism for the formation of 10 and 15 through route (A)
was not undertaken, the reaction pathway is considered to proceed via
Scheme 3.

1,3-Dithiolan-2-ones
Table 1. Compound 15
759
15
Ar
Ar1
a
b
c
d
e
f
C6H5
C6H5
C6H5
4-CH3-C6H4
4-OCH3-C6H4
4-Cl-C6H4
C6H5
4-CH3-C6H4
4-CH3-C6H4
4-CH3-C6H4
4-CH3-C6H4
4-OCH3-C6H4
4-OCH3-C6H4
4-OCH3-C6H4
4-OCH3-C6H4
4-Cl-C6H4
4-CH3-C6H4
4-OCH3-C6H4
4-Cl-C6H4
C6H5
g
h
i
4-CH3-C6H4
4-OCH3-C6H4
4-Cl-C6H4
C6H5
j
k
l
m
n
o
4-Cl-C6H4
4-Cl-C6H4
4-Cl-C6H4
4-CH3-C6H4
4-OCH3-C6H4
4-Cl-C6H4
cleavage of the exocyclic double bond under the reaction conditions in the
dithiolanes 8 and cyanoacetanilide elimination. The latter reacts with 9 or
14 to yield products 10 or 15, respectively. Similar reactions were previously
reportect.[7–10]
In summary, we have achieved a regiospecifc synthesis of interesting
novel 1,3-dithiolane derivatives by the reaction of sodium a-cyanoketene
dithiolates with chloroacetic acid followed by cyclization. The compounds
obtained seem promising for further chemical transformations.
EXPERIMENTAL
All melting points were determined on an electrothermal melting-point apparatus
and are uncorrected. IR (cm21) spectra were recorded on KBr disk on a FT IR-
1
8201 PC Schimadzu spectrophotometer. H NMR spectra were recorded in
CDCl3 or (CD3)2SO on a Gemini 200-MHz spectrophotometer using TMS as
internal reference, and chemical shifts are expresses as d ppm unit. Mass spec-
troscopy was recorded on a GC-MS QP1000 EX Shimadzu. Elemental
analyses were performed at the microanalytical center at Cairo University.
Ethyl f[3-(Arylamino)–2-cyano-l-mercapto-3-oxoprop-1-enyl]thiog
acetate (6a–d), General Procedure
Ethyl bromoacetate (1.67 gm, 0.01 mol) was added in portions at room temp-
erature to a solution of compounds 3a–d (0.01 mol) in ethanol (20 mL). The
reaction mixture was left for 2 h under stirring, then poured over iced water,

760
G. H. Elgemeie et al.
and neutralized with dilute hydrochloric acid. The precipitated product was
filtered off and recrystallized from absolute ethanol (20 mL).
6a: Yellow, mp 203 8C; yield 90%. nmax/cm21 (KBr), 3271 (NH); 2206 (CN),
1
1735 (CO), 1670 (CO) cm21; H NMR (DMSO) d 1.97 (t, 3H, CH3), 3.74
(s, 2H, CH2), 4.87 (q, 2H,CH2), 7.71–7.96 (m, 5H, C6H5), 9.21 (s, 1H,
NH), and 10.64 (s, 1H, SH). Found: C, 52.35; H, 4.61; N, 8.43%. Calcd. for
C14H14N2O3S2: C, 52.17; H, 4.35; N, 8.70%.
6b: Yellow, mp 220 8C, yield 80%. nmax/cm21 (KBr), 3282 (NH), 2202 (CN),
1
1735 (CO), 1635 (CO) cm21; H NMR (DMSO) d 1.59 (t, 3H, CH3), 2.66
(s, 3H, CH3), 4.37 (s, 2H, CH2), 4.54 (q, 2H,CH2), 7.22–7.62 (m, 4H,
C6H4), 8.12 (s, IH, NH); m/z 336. Found: C, 53.82; H, 4.82; N, 8.51%.
Calcd. for C15H16N2O3S2: C, 53.57; H, 4.76; N, 8.33%.
6c: Yellow, mp 235 8C, yield 85%. nmax/cm21 (KBr), 3275 (NH); 2200 (CN),
1
1700 (CO), 1660 (CO) cm21; H NMR (DMSO) d 1.36 (t, 3H, CH3), 2.82
(s, 3H, OCH3), 3.16 (s, 2H, CH2), 4.33 (q, 2H, CH2), 6.90–7.46 (m, 4H,
C6H4), 7.99 (s, 1H, NH), 12.00 (s, 1H, SH). Found: C, 51.41; H, 4.61; N,
7.63%. Calcd. for C15H16N2O4S2: C, 51.14; H, 4.55; N, 7.95%.
6d: Yellow, mp 233 8C, yield 89%. nmax/cm21 (KBr), 3420 (NH); 2203 (CN),
1
1695 (CO), 1670 (CO) cm21; H NMR (DMSO) d 1.23 (t, 3H, CH3), 3.63
(s, 2H, CH2), 4.17 (q, 2H, CH2), 7.38–7.63 (m, 4H, C6H4), 8.85 (s, 1H,
NH), 10.41 (s, 1H, SH); m/z 358. Found: C, 47.41; H, 3.43; N, 7.58%.
Calcd. for C14H13N2O3S2Cl: C, 47.12; H, 3.65; N, 7.85%.
f[3-(Arylamino)-2-cyano-1-mercapto-3-oxoprop-1-enyl]thiogacetic
Acids 7a–d, General Procedure
a-Chloroacetic acid (0.94 gm, 0.01 mol) was added in portions to a solution
of compounds 3a–d (0.01 mol) in ethanol (20 mL) at room temperature.
The reaction mixture was left for 30 min under stirring, then poured over an
ice–water mixture, and neutralized with dilute hydrochloric acid. The preci-
pitated product was filtered off and recrystallized from ethanol.
7a: Yellow, mp 190 8C, yield 92%. nm.cm21(KBr), 3551, 3417 (OH, NH);
2202 (CN), 1690 (CO), 1675 (CO) cm21. Found: C, 48.63; H, 3.62; N,
9.31% Calcd. for C12H10N2O3S2: C, 48.98; H, 3.40; N, 9.52%.
7b: Yellow, mp 245 8C, yield 84%. nmax/cm21 (KBr), 3460, 3340 (OH, NH);
1
2200 (CN), 1697 (CO), 1670 (CO) cm21; H NMR (DMSO) d 2.29 (s, 3H,
CH3), 4.33 (s, 2H, CH2), 6.20–7.65 (m, 4H, C6H4), 9.50 (s, 1H, NH), 9.90
(s, 1H, SH), 12.31 (s, 1H, OH); m/z 307. Found: C, 50.42; H, 3.72; N,
9.21%. Calcd. for C13H12N2O3S2: C, 50.65; H, 3.90; N, 9.09%.
7c: Yellow, mp 205 8C, yield 81%. nmax/cm21 (KBr), 3400, 3330 (OH, NH);
1
2211 (CN), 1695 (CO), 1655 (CO) cm21; H NMR (DMSO) d 3.97 (s, 3H,

1,3-Dithiolan-2-ones
761
OCH3), 4.62 (s, 2H, CH2), 7.10–7.64 (m, 4H, C6H4), 9.88 (s, 1H, NH), 10.05
(s, 1H, SH), 10.36 (s, 1H, OH); m/z 326. Found: C, 48.43; H, 3.52; N, 8.42%.
Calcd. for C13H12N2O4S2: C, 48.15; H, 3.70; N, 8.64%.
7d: Yellow, mp 220 8C, yield 80%. nmax/cm21 (KBr), 3460–2500 (OH, NH);
1
2200 (CN), 1697 (CO), 1670 (CO) cm21; H NMR (DMSO) d 3.96 (s, 2H,
CH2), 6.34–7.62 (m, 4H, C6H4), 10.29 (s, 1H, NH), 10.48 (s, 1H, SH),
12.99 (s, 1H, OH); m/z 331. Found: C, 43.61; H, 2.52; N, 8.33%. Calcd.
for C12H9N2O3S2Cl: C, 43.84; H, 2.74; N, 8.52%.
N-Aryl-2-cyano-2-(4-oxo-1,3-dithiolan-2-ylidene)-acetamides
(8a–d), General Procedure
Compounds 6a–d or 7a–d (0.01 mol) were heated in sodium ethoxide
(0.046 g 0.01 mol) and ethanol (30 mL) for 30 min and then cooled. The
mixture was poured over an ice–water mixture and neutralized with dilute
hydrochloric acid, and the precipitated product was filtered off and recrystal-
lized from the appropriate solvent.
8a: Yellow, from ethanol, mp 190 8C, yield 75%. nmax/cm21 (KBr) 3290
1
(NH), 2205 (CN), 1679 (CO), 1658 (CO) cm21; H NMR (DMSO) d 4.40
(s, 2H, CH2), 7.26–7.55 (m, 5H, C6H5), 12.00 (s, 1H, NH); m/z 276.
Found: C, 52.32; H, 3.01; N, 10.32%. Calcd. for C12H8N2O2S2: C, 52.17;
H, 2.89; N, 10.14%.
8b: Yellow, from ethanol, mp 165 8C, yield 79%. nmax/cm21 (KBr), 3280
1
(NH), 2206 (CN), and 1742 (CO), 1636 (CO) cm21; H NMR (DMSO) d
2.23 (s, 3H, CH3), 3.67 (s, 2H, CH2), 7.12–7.55 (m, 4H, C6H4), 12.44
(s, 1H, NH); m/z 290. Found: C, 53.63; H, 3.61; N, 9.81%. Calcd. for
C13H10N2O3S2: C, 53.79; H, 3.45; N, 9.66%.
8c: Yellow, from ethanol, mp 185 8C yield 85%. nmax/cm21 (KBr), 3327
(NH), 2208 (CN), and 1685 (CO), 1660 (CO) cm21. Found: C, 51.01; H,
3.42; N, 9.32%. Calcd. for C13H10N2O3S2: C, 50.98; H, 3.26; N, 9.15%.
8d: Yellow, from EtOH, mp 250 8C, yield 80%. nmax/cm21 (KBr), 3316 (NH),
2203 (CN), 1680, 1656 (CO) cm21. Found: C, 46.62; H, 2.41; N, 9.31%.
Calcd. for C12H7N2O2S2Cl: C, 46.45; H, 2.25; N, 9.03%.
6-Amino-1-aryl-4-(methylthio)-2-oxo-1,2-dihydropyridine-3,5-
dicarbonitriles (10a–d)
Method (a): General Procedure
A mixture of 8a–d (0.01 mol) and bis(methylthiomethylene)malononitrile 9
(1.70 g, 0.01 mol) was boiled under reflux in ethanol (30 mL) containing a

762
G. H. Elgemeie et al.
catalytic amount of piperidine for 30 min and then cooled. The precipitated
product was filtered off and recrystallized from ethanol.
Method (b): General Procedure
A mixture of bis(methylthiomethylene)malononitrile 9 (1.70 g, 0.01 mol) and
N-arylcyanoacetamide derivatives 1 was heated in ethanol (40 mL) in the
presence of catalytic amounts of piperidine for 1 h and then cooled. The
precipitated product was filtered off and recrystallized from ethanol.
6-Amino-1,4-diaryl-2-oxo-1,2-dihydropyridin-3,5-dicarbonitriles
(15a–o)
Method (a): General Procedure
A mixture of compounds 8 (0.01 mol) and arylmethylenemalononitriles 14
(0.01 mol) was refluxed in ethanol (30 mL) in the presence of catalytic
amounts of piperidine for 30 min and then cooled. The precipitated product
was filtered off and recrystallized from ethanol.
Method (b): General Procedure
A mixture of arylmethylenemalononitriles 14 (0.01 mol) and N-aryl-cyano-
acetamide derivatives 1 (0.01 mol) was refluxed in ethanol (30 mL) containing
catalytic amounts of piperidine (3 drops) for 20 min and then cooled. The
formed product was filtered off and recrystallized from ethanol.
15a: Buff, mp . 300 8C, yield 70%. nmax/cm21 (KBr), 3440, 3190 (NH2),
1
2214 (2CN), and 1654 (CO) cm21; H NMR (DMSO) d 2.51 (s, 3H, CH3),
7.25–7.58 (m, 9H, C6H4 and C6H5), 7.79 (s, 2H, NH2); m/z 326. Found: C,
73.76; H, 3.99; N, 17.42%. Calcd. for C20H14N4O: C, 73.62; H, 4.29; N,
17.18%.
15b: Buff, mp . 300 8C, yield 75%. nmax/cm21 (KBr), 3421, 3193 (NH2),
2210 (2CN), and 1666 (CO) cm21. Found: C, 70.43; H, 4.11; N, 16.45%.
Calcd. for C20H14N4O2: C, 70.18; H, 4.09; N, 16.37%.
15c: Yellow, mp . 300 8C, yield 70%. nmax/cm21 (KBr), 3440, 3197 (NH2),
1
2218 (2CN), and 1635 (CO) cm21; H NMR (DMSO) d 7.45–7.70 (m, 9H,
C6H4 and C6H5), 8.00 (s, 2H, NH2); m/z 346. Found: C, 65.66; H, 3.36; N,
16.51% Calcd. for C19H11N4OCl: C, 65.90; H, 3.18; N, 16.18%.
15d: Buff, mp . 300 8C, yield 75%. nmax/cm21 (KBr), 3445, 3190 (NH2),
2213 (2CN), 1660 (CO) cm21. Found: C, 73.46; H, 3.99; N, 17.22%. Calcd.
for C20H14N4O: C, 73.62; H, 4.29; N, 17.18%.

1,3-Dithiolan-2-ones
763
15e: Yellow, mp . 300 8C, yield 71%. nmax/cm21 (KBr), 3456, 3201 (NH2),
1
2221 (2CN), and 1654 (CO) cm21; H NMR (DMSO) d 2.40 (s, 3H, CH3),
2.42 (s, 3H, CH3), 7.25–7.49 (m, 8H, 2C6H4), 7.81 (s, 2H, NH2); m/z 340.
Found: C, 74.35; H, 4.55; N, 16.63%. Calcd. for C21H16N4O: C, 74.12; H,
4.71; N, 16.97%.
15f: Yellow, mp . 300 8C, yield 65%. nmax/cm21 (KBr), 3429, 3201 (NH2),
2221 (2CN), 1635 (CO) cm21; Found: C, 70.53; H, 4.31; N, 15.64%. Calcd.
for C21H16N4O2: C, 70.79; H, 4.49; N, 15.73%.
15g: Buff, mp . 300 8C, yield 63%. nmax/cm21 (KBr), 3435, 3197 (NH2),
2210 (2CN), 1650 (CO) cm21. Found: C, 66.45; H, 3.72; N, 15,43%. Calcd.
for C20H13N4OCl: C, 66.66; H, 3.61; N, 15.55%.
15h: Yellow, mp . 300 8C, yield 75%. nmax/cm21 (KBr), 3445, 3201 (NH2),
2216 (2CN), 1644 (CO) cm21. Found: C, 70.32; H, 4.22; N, 16.33%. Calcd.
for C20H14N4O2: C, 70.18; H, 4.09; N, 16.37%:
15i: Buff, mp . 300 8C, yield 69%. nmax/cm21 (KBr), 3456, 3197 (NH2),
1
2221 (2CN), and 1651 (CO) cm21; H NMR (DMSO) d 2.42 (s, 3H, CH3),
3.87 (s, 3H, OCH3) 7.12–7.55 (m, 8H, 2C6H4), 7.74 (s, 2H, NH2); m/z
356. Found: C, 70.64; H, 4.43; N, 15.54%. Calcd. for C21H16N4O2: C,
70.79; H, 4.49; N, 15.73%.
15j: Yellow, mp . 300 8C, yield 75%. nmax/cm21 (KBr), 3398, 3190 (NH2),
2210 (2CN), and 1658 (CO) cm21; 1H NMR (DMSO) d 3.80 (s, 3H, OCH3),
3.85 (s, 3H, OCH3), 7.12–7.55 (m, 8H, 2C6H4), 7.76 (s, 2H, NH2). Found: C,
67.55; H, 4.31; N, 15.21%. Calcd. for C21H16N4O3: C, 67.74; H, 4.30; N,
15.05%.
15k: Yellow, mp . 300 8C, yield 72%. nmax/cm21 (KBr), 3430, 3195 (NH2),
2214 (2CN), and 1652 (CO) cm21. Found: C, 63.77; H, 3.22; N, 15.11%.
Calcd. for C20H13N4O2Cl: C, 63.83; H, 3.46; N, 14.89%.
15l: Buff, mp . 300 8C, yield 65%. nmax/cm21 (KBr), 3440, 3198 (NH2),
2218 (2CN), and 1644 (CO) cm21. Found: C, 65.51; H, 3.26; N, 16.22%.
Calcd. for C19H11N4OCl: C, 65.90; H, 3.18; N, 16.18%.
15m: Buff, mp . 300 8C, yield 61%. nmax/cm21 (KBr), 3398, 3193 (NH2),
2214 (2CN), and 1651 (CO) cm21. Found: C, 66.57; H, 3.55; N, 15.62%.
Calcd. for C20H13N4OCl: C, 66.66; H, 3.61; N, 15.55%.
15n: Buff, mp . 300 8C, yield 64%. nmax/cm21 (KBr), 3398, 3193 (NH2),
1
2214 (2CN), 1655 (CO) cm21; H NMR (DMSO) d 3.87 (s, 3H, OCH3)
7.13–7.66 (m, 8H, 2C6H4), 7.94 (s, 2H, NH2). Found: C, 63.56; H, 3.32; N,
14.77%. Calcd. for C20H13N4O2Cl: C, 63.83; H, 3.46; N, 14.89%.
15o: Yellow, mp . 300 8C, yield 76%. nmax/cm21 (KBr), 3398, 3194 (NH2),
2214 (2CN), 1651 (CO) cm21. Found: C, 59.66; H, 2.54; N, 14.53%. Calcd.
for C20H13N4O2Cl2: C, 59.84; H, 2.62; N, 14.70%.

764
G. H. Elgemeie et al.
REFERENCES
1. Elgemeie, G. H.; Elghandour, A. H.; Elzanate, A. M.; Ahmed, S. A. Synthesis of
some novel a-cyanoketene S,S-acetals and their use in heterocyclic synthesis.
J. Chem. Soc., Perkin Trans. 1 1997, 3285–3290.
2. Elgemeie, G. H.; Ali, H. A.; Elghandour, A. H.; Abd-Elaziz, G. W. Synthesis of
novel derivatives of 4-methylthio-N-aryl-2-pyridone and deazapurine analogues:
The reaction of ketene dithioacetals with substituted acetanilides. Phosphorus,
Sulfur, Silicon, Relat. Elem. 2000, 164, 189–197.
3. Elgemeie, G. H.; Elees, S. A.; Elsakka, I.; Elnagdi, M. H. Activated nitriles in
heterocyclic synthesis: The reaction of cinnamonitrile derivatives with active
methylene reagents. Z. Naturforsch., B: Chem. Sci. 1983, 38B, 639–642.
4. Kandeel, Z. E.; Hassan, K. M.; Ismail, N. A.; Elnagdi, M. H. Activated nitriles in
heterocyclic synthesis: Novel synthesis of pyrimidine and pyridine derivatives.
J. Prakt. Chem. 1984, 326, 248–252.
5. Ismail, A. H.; Hwatta, M. Synthesis of pyridinone and pyrazolopyridinone deriva-
tives. Kagaku Kogyo 1997, 71, 102–105.
6. Metwally, N.; Abdelrazik, F. Heterocyclic synthesis with nitriles: Synthesis of
some novel pyrrolo[2,1-b]thiazolo[2,3-a]pyrimidine and pyridine derivatives.
J. Prakt. Chem. 1998, 340, 676–678.
7. Elgemeie, G. H.; Regaila, H. A.; Shehata, N. Unexpected products of the reaction
of cycloalkylidene(cyano)-thioacetamides with arylmethylenemalononitriles: A
different novel route to condensed pyridine-2(1H)-thiones and condensed carbo-
cyclic nitriles. J. Chem. Soc., Perkin Trans. 1 1990, 1267–1270.
8. Elgemeie, G. H.; Shams, H. Z.; Elkholy, Y. M.; Abbaas, N. Novel synthesis of N-
amino-2-pyridones and cycloalkane ring-fused pyridines containing benzothiazole
moiety. Heterocyclic Comm. 2000, 6, 363–368.
9. Elgemeie, G. H. Novel synthetic route to pyridine-2(1H)-thiones, unexpected
products of the reaction of b-phenathylidenemalononitriles with arylmethylene-
cyanothioacetamides. Heterocycles 1990, 31, 123–127.
10. Elgemeie, G. H.; Fathy, N. M.; Attia, A. M. Studies on 1,2,3,4-tetrahydro-1-
naphthylidenemalononitrile: Role of thermodynamic and kinetic factors on the
products of the reaction with arylmethylidene(cyano)acetamides. J. Chem. Res.,
Synop. 1995, 292–293.