1,4-Phenylenediisothiocyanate in the synthesis of bis-(thiourea, benzothiazole, quinazoline, 1,3-benzoxazine and imidazolidineiminothiones) derivatives

Article abstract of DOI:10.1080/10426500490274682

Interaction of 1,4-phenylenediisothiocyanate 1 with aromatic amines and o-phenylenediamine furnished the novel bisthiourea derivatives 2a-c and 7. Hydrazines or o-aminothiophenol reacted with 1 to produce bis- (thiosemicarbazide 4a,b or benzothiazole 9) d

Full text of DOI:10.1080/10426500490274682

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1,4-PHENYLENEDIISOTHIOCYANATE IN THE SYNTHESIS
OF BIS-(THIOUREA, BENZOTHIAZOLE, QUINAZOLINE,
1,3-BENZOXAZINE AND IMIDAZOLIDINEIMINOTHIONES)
DERIVATIVES
A. M. Sh. El-Sharief a , Y. A. Ammar a , M. A. Zahran a & H. Kh. Sabet a
a Al-Azhar University, Nasr City, Cairo, Egypt
Version of record first published: 11 Aug 2010
To cite this article: A. M. Sh. El-Sharief, Y. A. Ammar, M. A. Zahran & H. Kh. Sabet (2004): 1,4-PHENYLENEDIISOTHIOCYANATE
IN THE SYNTHESIS OF BIS-(THIOUREA, BENZOTHIAZOLE, QUINAZOLINE, 1,3-BENZOXAZINE AND IMIDAZOLIDINEIMINOTHIONES)
DERIVATIVES, Phosphorus, Sulfur, and Silicon and the Related Elements, 179:2, 267-275
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Phosphorus, Sulfur, and Silicon, 179:267–275, 2004
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Copyright Taylor & Francis Inc.
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426500490274682
1,4-PHENYLENEDIISOTHIOCYANATE IN THE
SYNTHESIS OF BIS-(THIOUREA, BENZOTHIAZOLE,
QUINAZOLINE, 1,3-BENZOXAZINE AND
IMIDAZOLIDINEIMINOTHIONES) DERIVATIVES
A. M. Sh. El-Sharief, Y. A. Ammar, M. A. Zahran,
and H. Kh. Sabet
Al-Azhar University, Nasr City, Cairo, Egypt
(Received August 29, 2002; accepted July 29, 2003)
Interaction of 1,4-phenylenediisothiocyanate 1 with aromatic amines
and o-phenylenediamine furnished the novel bisthiourea derivatives
2a–c and 7. Hydrazines or o-aminothiophenol reacted with 1 to produce
bis-(thiosemicarbazide 4a,b or benzothiazole 9) derivatives. Bisquina-
zolines 12a,b and bisthienopyrimidines 13a,b were synthesized
through interaction of 1 with anthranilic acids 10a,b and aminoth-
iophenes 11a,b. Interaction of 1 with two moles of either salicylic
acid or N-(4-substituted-phenyl)cyanothioformamide yielded the cor-
responding bis(1,3-benzoxazine 14 or imidazolidineiminothiones 16)
derivatives.
Keywords: 1,4-Phenylenediisothiocyanate; bis-benzothiazole; bis-
quinazoline; bis-1,3-benzoxazine
A literature survey reveals that, attention has been increasingly paid
to the synthesis of bisheterocyclic compounds, which exhibit various
biological activities1−4 including antibacterial, fungicidal, tuberculo-
static, and plant growth regulative properties. Earlier work5 revealed
that bisheterocyclic compounds displayed much better antibacterial
activity than heterocyclic compounds. As an extension of our efforts
directed toward the development of convenient synthetic approaches
for the synthesis of heterocyclic compounds6−10 with an expected
broad spectrum of biological activity, in this article we report on the
synthesis of bis-(thiourea, quinazoline, 1,3-Benzoxazine and imidazo-
lidineiminothiones) starting with 1,4-phenylenediisothiocyanate. The
starting material 1 was prepared according to the reported method.11
Address correspondence to A. M. Sh. El-Sharief, Chemistry Department, College of
Science, King Abdul-Aziz University, Madinah Munawwara, PO Box 344, Kingdom of
Saudi Arabia.
267

268
A. M. Sh. El-Sharief et al.
RESULTS AND DISCUSSION
The behavior of 1 toward some mono and binucleophilic reagents
was discussed. Thus, treatment of 1,4-phenylenediisothiocyanate 1
with aromatic amines yielded the novel bisthiourea derivatives 2a–c.
The elemental and spectroscopic data of 2a–c are consistent with
1
the assigned structure. Thus, a representive example, H NMR spec-
trum of 2b in DMSO-d6 revealed a singlet at δ 3.76 assigned to
two OCH3 groups and a multiplet at δ 6.9–7.74 assigned to the aro-
matic protons and broad at δ 9.57 assigned to NH groups. Also,
when 1 was treated with glycine as another nucleophile the corre-
sponding {3-[4-(3-carboxymethylthioureido)phenyl]-thioureido}-acetic
acid 3 was obtained. In addition, 1,4-phenylenediisothiocyanate 1
was treated with hydrazine hydrate and phenyl hydrazine as binu-
cleophile, and furnished upon heating in dioxane under reflux prod-
ucts that could be formulated as the bisthiosemicarbazides 4a,b.
The structures of compounds 4a,b were established on the basis
of their elemental analyses and spectral data (IR, 1H NMR, mass
spectra). Mass spectrum of 4a exhibited a molecular ion peak cor-
responding to the formula C8H12N6S2 (M+ = 256). On the other
hand, when 1 was reacted with benzoyl hydrazine the correspond-
ing 4-(4-(2-benzoylhydrazino-thiocarbonylaminophenyl)-5-phenyl-2,4-
dihydro-[1,2,4]triazole-3-thione 5 was obtained. The mass spectrum of 5
showed the molecular ion peak at m/z 446 corresponding to the formula
C22H18ON6S2 (Scheme 1).
SCHEME 1

Urea, Azole, Azoline, Azine, and Thione Derivatives
269
Next, we moved to investigate the behavior of isothiocyanate
1 toward some 1,2-binucleophiles. Thus, compound 1 reacted with
o-phenylenediamine in refluxing dioxane/TEA to yield a single prod-
uct with analytical and spectral data indicated that two moles of the
reagent were consumed without elimination of H2S. Consequently, we
assigned the thiourea derivative 7 to this reaction product. Mass spec-
trum of 7 reveals a molecular ion peak at m/z 408 (38.46%) correspond-
ing to the molecular formula C20H20N6S2. The structure of 7 also was
confirmed through its acylation with acetic anhydride to give the ac-
1
etanilide derivative 8. Its H NMR spectrum in DMSO-d6 revealed a
singlet at δ 3.01 assigned to two COCH3 groups and a multiplet at δ
7.18–7.32 assigned to the aromatic protons and singlet at δ 7.50, 7.51,
7.99, 8.03, and 13.7 assigned to NH groups. On the other hand, the
reaction of 1 with o-aminothiophenol afforded the corresponding N,Nꢁ-
Bis-(benzothiazole-2-yl)-benzene-1,4-diamine 9 which elucidated by el-
emental and spectral data. (Scheme 2).
SCHEME 2
Quinazoline and thienopyrimidine derivatives proved to be a good
CAMP phosphodiesterase inhibitor with an excellent antianxiety pro-
file in animals.12 Other derivatives showed antipyretic,13 antitumor,14
and herbicidal activities.15 Encouraged by such properties, we planned
to synthesize bisquinazoline and thienopyrimidine derivatives. Thus,
interaction of 1 with anthranilic acids 10a,b in dioxane/TEA caused cy-
clocondensation to furnish the corresponding bisquinazolinone deriva-
tives 12a,b in acceptable yield.
Compound 12a was found to be identical in every respect
to the compound prepared according to the reported method.16
Compounds 12a,b resulted from a competitive nucleophilic attack

270
A. M. Sh. El-Sharief et al.
SCHEME 3
of the COOH group on the intermediate thiourea where H2O
was eliminated. Similarly, interaction of 1 with 2-amino-3-cyano-
4,5,6,7-tetrahydrobenzo[b]thiophene 11a and ethyl-2-amino-4,5,6,7-
tetrahydrobenzo[b]thiophene-3-carboxylate 11b yielded the corre-
sponding bisthienopyrimidine derivatives 13a,b (Scheme 3). Structure
13a,b was established on elemental analyses and spectroscopic stud-
ies. The mass spectrum of 13a revealed a molecular ion peak at 550
which in agreement with the proposed formula C26H22N4O2S4. On the
other hand, refluxing of diisothiocyanate 1 with salicylic acid in diox-
ane caused cyclization to produce the 3,3ꢁ-(1,4-phenylene)bis(2-thioxo-
2,3-dihydro-benzo[e][1,3]oxazine-4-one 14 through elimination of H2O
(Scheme 3). Its mass spectrum assigned a molecular ion peak at m/z
432 (28.26%).
Finally, this investigation was extended to cover the behavior of
1 toward cyanothioformanilides. Thus, compound 1 reacted with
N-phenyl-cyanothioformamide, where 1 mmol was consumed and
yielded 5-imino-(4-isothiocyanato-phenyl)-3-phenyl-imidazolidine-2,4-
dithione 15 (Scheme 4). While, on refluxing of 1,4-phenylenediisothio-
cyanate 1 with N-(4-substituted phenyl)cyanothioformamide in THF
in the presence of TEA two moles were consumed and afforded

Urea, Azole, Azoline, Azine, and Thione Derivatives
271
SCHEME 4
1,1ꢁ-(1,4-phenylene)bis[3-(4-substituted
dine-2,4-dithiones] 16a,b. Imine hydrolysis of 16b using DMF/HCl
afforded
1,1ꢁ-(1,4-phenylene)bis[3-(4-chloro-phenyl)-5-oxo-imidazoli-
phenyl)-5-imino-imidazoli-
dine-2,4-dithione] 16c (Scheme 4).
EXPERIMENTAL
All melting points are uncorrected. IR spectra(KBr)were measured on
shimadzu 440 spectrometer, 1H NMR spectra were obtained in DMSO
on a Varian Gemini 200 MHz spectrometer using TMS as internal stan-
dard; chemical shifts are reported as (ppm). Mass spectra were obtained
on GC MS\QP 1000 Ex mass spectrometer at 70 eV. Elemental analyses
were carried out at the Microanalytical Center, Faculty of Science (Cairo
University, Egypt). The characteristics data for prpared compounds are
given in Table I.
The starting compound 1,4-phenylenediisothiocyanate 1 was pre-
pared according to the reported method.12
1,4-Bisthioureas 2a–c: A mixture of 1 (0.01 mmol) in dioxane
(30 ml), primary amine (0.02 mmol), and triethylamine (0.5 ml) was
refluxed for 6 h. The solid that obtained on heating was boiled with
dioxane to give 2a–c. IR (2a): 3224 (NH), 3016 (CH-arom.), 1550 and
1
1018 (C S). IR (2b): 3224 (NH), 1512 and 1242 (C S). H NMR (2b;
DMSO-d6): 3.76(s, 3H, 2OCH3), 6.9–7.45 (m, 12H, Ar-H), 9.57 (br, 4H,
4NH, D2O-exchangeable). 1H NMR (2c; DMSO-d6): 1.32 (t, 6H, 2CH3),
4.02 (q, 4H, 2OCH2), 6.87–744 (m, 12H, Ar-H), 9.5 (s, 4H, 4NH; D2O-
exchangeable).
{3-[4-(3-Carboxymethylthioureido)phenyl]thioureido}acetic
acid 3: A mixture of 1 (0.01 mmol) in THF (30 ml), glycine (0.02 mmol)

272
A. M. Sh. El-Sharief et al.
TABLE I Characteristics Data for the Prepared Compounds
Elemental analyses
Calcd./Found
Compd.
No.
Mol Formula
(mol.wt.)
m.p. [◦C] Yield (%)
C
H
N
S
2a
2b
2c
260
274
90
95
95
70
86
76
53
78
56
84
67
56
68
77
66
49
75
54
76
C22H22N4S2
(406)
C22H22N4O2S2
(438)
64.99 5.45
64.90 5.40
60.25 5.06
60.20 5.10
61.78 5.62
61.70 5.60
42.10 4.12
42.00 4.10
37.48 4.72
37.40 4.60
58.80 4.93
58.70 4.90
59.17 4.06
59.10 4.10
58.80 4.93
58.80 4.80
58.52 4.91
58.50 4.80
64.15 3.77
64.10 3.70
61.38 3.28
61.30 3.20
46.50 1.77
46.50 1.70
56.91 4.41
56.80 4.30
56.70 4.03
56.60 4.10
61.10 2.80
61.10 2.70
54.21 2.84
54.10 2.80
55.79 3.12
55.70 3.00
49.23 2.41
49.20 2.30
49.06 2.06
48.90 1.95
13.78 15.77
13.70 15.70
12.77 14.62
12.70 14.60
12.01 13.74
12.10 13.80
16.36 18.73
16.30 18.70
32.78 25.02
32.70 24.90
20.57 15.70
20.50 15.60
18.82 14.36
18.70 14.30
20.57 15.70
20.50 15.60
17.06 13.02
16.90 12.90
14.96 17.12
14.90 17.10
13.01 14.90
13.10 14.80
245
C
24H26N4O2S2
(466)
3
280
C12H14N4O4S2
(342)
C8 H12N6S2
(256)
C20H20N6S2
(408)
4a
4b
5
185
210
>300
185
C
22H18N6OS2
(446)
7
C
20H20N6S2
(408)
8
260
C
24H24N6O2S2
(492)
9
>300
>300
>300
200
C
20H18N4S4
(374)
12a
12b
13a
13b
14
C22H14N4O2S2
(430)
22H14N4O2S2Cl4
(568)
C
9.86
9.80
11.28
11.20
C
26H24 N6S4
(548)
15.31 23.37
15.20 23.30
10.17 23.29
10.10 23.20
>300
>300
260
C
C
26H22N4O2S4
(550)
22H12N2O4S2
(432)
6.48
6.40
14.83
14.80
15
C16H10N4S3
(354)
15.81 27.14
15.80 27.10
16.27 24.82
16.20 24.80
14.35 21.90
14.30 21.80
16a
16b
16c
>300
>300
280
C
24H16N6S4
(516)
C
24H14N6S4Cl2
(584)
24H12N4S4O2Cl2
(586)
C
9.54
9.50
21.83
21.80
in NaOH (10 ml) was stirred at room temperature for 2 h; the product
was precipitated with dilute HCl, filtered, washed with water, dried,
then recrystallized from dioxane to give 3. IR: 3324, 3242 (NH), 2862
1
(CH-aliph.), 1719 (C O), 1534 and 1244 (C S). H NMR (DMSO-d6):

Urea, Azole, Azoline, Azine, and Thione Derivatives
273
4.2 (s, 6H, 2CH2 + 2NH), 7.2–7.4 (q, 4H, A-B system), 7.8 (s, 2H, 2NH),
9.7 (s, 2H, 2COOH).
Bisthiosemicarbazide derivatives 4a,b:
A solution of 1
(0.01 mmol) and hydrazine hydrate or phenyl hydrazine (0.02 mmol)
in dioxane (30 ml) was refluxed for 3 h; the solid which formed on heat-
ing was collected and washed with dioxane to give 4a,b. IR (4a): 3295,
3223 (NH2), (NH), 1507 and 1270 (C S). MS (4a; %): 256 (M+; 9.53), 257
(M + 1; 6), 224 (35), 192 (25), 150 (100). 1H NMR (4b; DMSO-d6): 6.76–
7.44 (m, 14H, Ar-H), 7.97, 9.58, 9.71 (s, 6H, 6NH; D2O-exchangeable).
4-(4-(2-Benzoylhydrazino-thiocarbonylaminophenyl)-5-phen-
yl-4H-[1,2,4]triazole-3-thiol 5: A solution of 1 (0.01 mmol) and
benzoyl hydrazine (0.02 mmol) in dioxane (30 ml) was refluxed for 24 h;
the reaction mixture was allowed to cool and poured into cold water
(50 ml). The product was collected and recrystallized from dioxane to
give 5. IR: 3225 (NH), 1650 (C O), 1510 and 1224 (C S). MS (5; %):
446 (M+; 10), 382 (10), 343 (10), 258 (10), 134 (27), 103 (20), 75 (26),
and 52 (100).
1-(-Amino-phenyl)-3-{4-[3-(2-amino-phenyl)thioureido]-phen-
yl}thiourea 7: A mixture of 1 (0.01 mmol), o-phenylenediamine
(0.02 mmol), and triethylamine (0.5 ml) in dioxane (30 ml) was refluxed
for 6 h; the solid product which produced on heating was collected and
boiled with dioxane to give 7. IR: 3355, 3271 (NH2), (NH), 1531 and
1271 (C S). MS (7; %): 408 (M+; 38), 365 (42), 327 (42), 296 (50), 257
(38), 249 (69), 229 (62), 209 (53), 195 (84), and 128 (100).
N-[2-(3-{4-[3-(2-Acetylaminophenyl)thioureido]-phenyl}thio-
ureido)-phenyl] acetamide 8: Compound 7 (0.01 mmol) was refluxed
with acetic anhydride (10 ml) for 3 h then allowed to cool. The solid
product was collected then recrystallized from ethanol to give 8.
IR: 3153, 3109 (NH), 2993 (CH-aliph.), 1716 (C O), 1458 and 1177
(C S). 1H NMR (DMSO-d6): 3.01 (s, 6H, 2COCH3), 7.18–7.32 (m, 12H,
Ar-H), 7.50, 7.51, 7.99, 8.03 (4H, 4NH; D2O-exchangeable), 13.7 (s, 2H,
2NH-COCH3; D2O-exchangeable).
N,Nꢀ-Bis-(benzothiazole-2-yl)-benzene-1,4-diamine 9: A mix-
ture of 1 (0.01 mmol), o-aminothiophenol (0.02 mmol), and triethy-
lamine (0.5 ml) in DMF (30 ml) was refluxed for 12 h then allowed to
cool and poured into cold water (50 ml). Acidification with HCl yielded a
solid product which was recrystallized from dioxane to give 9. IR: 3213
1
(NH), 3048 (CH-arom.), 1601 (C N). H-NMR (DMSO-d6): 7.36–8.26
(m, 12H, Ar-H) and 12.5 (s, 2H, 2NH; exchangeable with D2O) MS (9;
%): 374 (M+; 19), 375 (M+1; 19), 358 (35), 338 (47), 337 (100), 307(41),
296 (72), 239 (47) and 158 (59).
3,3ꢀ-(1,4-phenylene)bis(2-thioxo-4-oxo-2,3-dihydro-1H-quin-
azoline derivatives 12a,b: A mixture of 1 (0.01 mmol) and

274
A. M. Sh. El-Sharief et al.
anthranilic acid derivatives 10a,b (0.02 mmol) in dioxane (30 ml)
and triethylamine (0.5 ml) was refluxed for 3 h; the solid product
which produced on heating was collected and boiled with dioxane to
give 12a,b. IR (12a): 3213 (NH), 1662 (C O), 1532 and 1195 (C S). IR
(12b): 3376 (NH), 1681 (C O), 1508 and 1222 (C S). MS (12a; %): 430
(M+; 48), 364 (44), 339 (64), 323 (48), 278 (100), 254 (56), 246 (68), 215
(100), 152 (76). MS (12b; %): 568 (M+; 71), 569 (M+1; 56), 570 (M+2;
48), 571 (M+3; 26), 567 (100), 565 (65), 552 (20), 380 (27), 364 (22), 320
(44), 232 (36), 192 (2), 159 (35), 97 (22).
3,3ꢀ -(1,4-Phenylene)bis(4-Imino-3,4,5,6,7,8-hexahydro-1H-
benzo-[4,5]-thieno-[2,3-d]-pyrimidine-2-thione 13a and 3,3ꢀ-(1,
4-phenylene)bis(2-thioxo-2,3,5,6,7,8-hexahydro-1H-benzo[4,5]-
thieno-[2,3-d]-pyrimidin-4-one 13b: To a suspension of 1 (0.01
mmol) and 11a or 11b (0.02 mmol) in dioxane (30 ml), triethylamine
(0.5 ml) was added. The reaction mixture was heated under reflux for
3 h; the solid product which produced on heating was collected and
washed with hot dioxane to give 13a,b. IR (13a): 3267, 3157 (NH),
2932 (CH-aliph), 1556 and 1258 (C S). IR (13b): 3197 (NH), 2932
(CH-aliph), 1663 (C O), 1509 and 1228 (C S).1H NMR (13a): 1.77,
2.79 (m, 16H, 8CH2), 3.57 (s, 2H, 2SH), 5.8 (humb, 2H, 2NH), 7.07–7.44
(m, 4H, Ar-H). MS (13a; %): 548 (M+; 22.45), 549 (M+1; 29), 534 (46),
473 (38), 458 (63), 446 (32), 391 (57), 379 (46), 329 (59), 266 (85), and
225 (100). MS (13b; %): 550 (M+; 32), 551 (M+1; 30), 533 (55), 402 (53),
360 (62), 343 (46), 308 (69), 301 (32), 287 (32), 246 (37), 228 (55), and
182 (100).
3,3ꢀ-(1,4-Phenylene)bis(4-oxo-2-thioxo-2,3-dihydro-benzo[e]-
[1,3]-oxazine 14: A mixture of 2 (0.01 mmol), salicylic acid (0.02
mmol), and triethylamine (0.5 ml) in DMF (30 ml) was refluxed for 24
h. The obtained solid was recrystallized from dioxane to give 15. IR
(15): 1677 (C O) and 1515 and 1124 (CS-N). MS (15; %): 432 (M+; 28),
398 (44), 369 (44), 339 (54), 223 (46), 199 (54), 164 (48), 130 (50), 126
(70), and 86 (100).
5-Imino-(4-isothiocyanato-phenyl)-3-phenyl-imidazolidine-2,
4-dithione 15: A solution of 1 (0.01 mmol) in THF (30 ml), N-
phenylcyanothio-formamide (0.02 mmol) and few drops of triethy-
lamine was stirred at room temperature for 0.5 h; the solid obtained
was recrystallized from chloroform/pet. ether to give 15. IR (15): 3350
(NH), 2100 (-NCS), 1515 and 1198 (C S). MS (15): 354 (M+; 11.3), 355
(M+1; 9.2), 356 (M+3; 5.8), 339 (9.4), 313 (2.3), 192 (25), 176 (26), 162
(7.5), 135 (48), 77 (100).
1,1ꢀ-(1,4-Phenylene)bis[3-(4-substituted-phenyl)-5-imino-imi-
dazolidine-2,4-dithiones] 16a,b: A solution of 1 (0.01 mmol),
N-(4-substituted-phenyl)cyanothio-formamide (0.02 mmol), and

Urea, Azole, Azoline, Azine, and Thione Derivatives
275
triethylamine (0.5 ml) in THF (20 ml) was refluxed for 3 h. The
solid which formed on heating was collected and washed with hot
1
dioxane to give 16a,b. IR (16b): 3221 (NH), 1512 and 1280 (C S). H
NMR (16b; DMSO-d6): 7.22–7.85 (m, 12H, Ar-H), 9.96 (s, 2H, 2NH;
D2O-exchangeable). MS (16a; %) : 516 (M+; 2), 354 (60), 283 (7), 224
(5), 192 (53), 161 (17), 135 (89), 90 (30), 77 (100).
Hydrolysis of 16b: To a solution of 16b (0.01 mmol) in boiling DMF
(20 ml), conc. HCl (5 ml) was added. The obtained product was recrystal-
lized from dioxane to give 16c. IR (16c): 3062 (CH-arom.), 1756 (C O),
1513 and 1089 (C S).
REFERENCES
[1] H. Singh, L. D. S. Yadav, and B. K. Bhattacharya, J. Indian Chem. Soc., 56, 1013
(1979).
[2] N. C. Desai, Indian J. Chem. Sest. B, 32, 343 (1993).
[3] X. M. Feng, R. Chen, X. C. Liu, and Z. Y. Zhang, Chin. J. Appl.Chem., 8, 28 (1991).
[4] P. S. Upadhyaz, R. N. Vansdadia, and A. J. Baxi, Indian J. Chem. Sect. B, 29, 793
(1990).
[5] Z. Y. Zhang, X. Chen, L. L. Wei, and Z. L. Ma, Chem. Res. Chin. Univ., 7, 129 (1991).
[6] A. M. Sh. El-Sharief, Y. A. Ammar, Y. A. Mohamed, and M. S. A. El-Gaby, Heteroatom
Chemistry, 13, 291 (2002).
[7] M. A. Zahran, A. M. Sh. El-Sharief, M. S. A. El-Gaby, Y. A. Ammar, and U. H. El-Said,
Il Farmaco, 56, 277 (2001).
[8] Y. A. Ammar, M. M. Ghorab, A. M. Sh. El-Sharief, and Sh. I. Mohamed, Heteroatom
Chemistry, 13, 199 (2002).
[9] A. M. Sh. El-Sharief, Y. A. Ammar, Y. A. Mohamed, M. M. Ali, M. S. A. El-Gaby, and
A. S. Ali, Phosphorus, Sulfur, and Silicon, 173, 39 (2001).
[10] Y. A. Ammar, A. M. Sh. El-Sharief, M. A. Zahran, M. Z. El-Said, and U. H. El-Said,
J. Chem. Res. Synop., 325 (1995).
[11] J. Garin, E. Melendez, F. Merchan, P. Merino, and T. Tejero, Bull. Soc. Chim. Belg.,
98, 289 (1989).
[12] T. Novimson, R. Honson, M. K. Dimitt, et al., J. Med. Chem., 17, 645 (1974).
[13] M. H. El-Nagdi, Tetrahedron, 30, 279 (1974).
[14] M. H. El-Nagdi, D. H. Fleita, and M. R. H. El-Moghayar, Tetrahedron, 31, 63 (1975).
[15] B. W. Doming, U.S. Pat. No. 3, 833, 582 (1974); CA, 81, 973664 (1975).
[16] P. Merino, J. Orduna, and T. Tejero, J. Heterocyclic Chem., 27, 1345 (1990).