Synthesis and antifungal activity of novel pyrano[2',3':4,5]thiazolo[2,3-b]quinazolines, pyrido[2',3':4,5]thiazolo[2,3- b]quinazolines and pyrazolo[2',3':4,5]thiazolo[2,3-b]quinazolines

Article abstract of DOI:10.1016/S0014-827X(00)00042-2

The starting materials thiazolo[2,3-b]quinazolines (5a,b) were obtained in one pot synthesis by treating octahydroquinazoline (2) with chloroacetic acid and aromatic aldehydes. Thiazoloquinazoline (5) was reacted with CH₂(CN)₂/piperidine and CH₂(CN)₂/NaOH (CH₃OH), to furnish pyrano[2',3':4,5]thiazolo[2,3-b]quinazolines (6a,b) and pyrido[2',3':4,5]thiazolo[2,3-b]quinazoline (7), respectively. Refluxing of 5a with NH₂CSNH₂/KOH and hydrazines in ethanol furnished the corresponding, [1,3]thiazino[4'5':4,5]thiazolo[2,3-b]quinazoline (10) and pyrazolo[3',4':4,5]thiazolo[2,3-b]quinazolines (11a,b), respectively. Antifungal activity was shown for some of the synthesized compounds. (C) 2000 Elsevier Science S.A.

Full text of DOI:10.1016/S0014-827X(00)00042-2

www.elsevier.nl/locate/farmac
Il Farmaco 55 (2000) 287–292
Synthesis and antifungal activity of novel
pyrano[2%,3%:4,5]thiazolo[2,3-b]quinazolines,
pyrido[2%,3%:4,5]thiazolo[2,3-b]quinazolines and
pyrazolo[2%,3%:4,5]thiazolo[2,3-b]quinazolines
Soad M. Abdel-Gawad a, Mohamed S.A. El-Gaby b,*, Moustafa M. Ghorab c
a Department of Chemistry, Faculty of Science (Girl’s), Al-Azhar Uni6ersity, Cairo, Egypt
b Department of Chemistry, Faculty of Science, Al-Azhar Uni6ersity at Assiut, Assiut 71524, Egypt
c Department of Drug Radiation Research, National Centre for Radiation Research and Technology, PO Box 29, Nasr City, Cairo, Egypt
Received 30 July 1999; accepted 9 March 2000
Abstract
The starting materials thiazolo[2,3-b]quinazolines (5a,b) were obtained in one pot synthesis by treating octahydroquinazoline (2)
with chloroacetic acid and aromatic aldehydes. Thiazoloquinazoline (5) was reacted with CH2(CN)2/piperidine and CH2(CN)2/
NaOH (CH3OH), to furnish pyrano[2%,3%:4,5]thiazolo[2,3-b]quinazolines (6a,b) and pyrido[2%,3%:4,5]thiazolo[2,3-b]quinazoline (7),
respectively. Refluxing of 5a with NH2CSNH2/KOH and hydrazines in ethanol furnished the corresponding, [1,3]thiazino-
[4%5%:4,5]thiazolo[2,3-b]quinazoline (10) and pyrazolo[3%,4%:4,5]thiazolo[2,3-b]quinazolines (11a,b), respectively. Antifungal activity
was shown for some of the synthesized compounds. © 2000 Published by Elsevier Science S.A. All rights reserved.
Keywords: Thiazoloquinazolines; Pyranothiazoloquinazoline; Antifungal activity
1. Introduction
2. Chemistry
Quinazolines are reported to have a broad spectrum
of biological activities. Some are endowed with antimi-
crobial [1], antimalarial [2], anticonvulsant [3], antide-
pressant [4], antihistamine [5], stimulant [4], anticancer
[6] and antiinflammatory properties [7]. On the other
hand, some thiazole derivatives also have various bio-
logical properties like antimicrobial [8], anthelmintic [9],
immunorestoration [10] and antineoplastic [11]. These
observations prompted us to synthesize heterocyclic
The octahydroquinazoline 2 was synthesized by acid-
catalysed condensation of 1,3-cyclohexanedione (1), p-
fluorobenzaldehyde and thiourea in ethanol, by a
modification of the Biginelli reaction [12]. The structure
of 2 was confirmed by spectral data and elemental
analysis. The IR spectrum of 2 show absorption bands
at 3280, 3200 cm−1 (secondary amino group), 1700
cm−1 (CꢀO) and 1500,1220 cm−1 (CꢀS; amide II and
1
amide I). The CH-4 proton in the H NMR spectrum
compounds containing
a thiazolo[2,3-b]quinazoline
exhibited signal at 5.2 ppm region doublets. Also, two
downfield one proton singlets at 9.72 and 10.67 ppm
regions were assigned to the N1–H and N3–H protons
of the octahydroquinazoline structure. The mass spec-
trum of 2 exhibited a molecular ion peak at m/z 276
(57.82%) together with a base peak at m/z 122. The
fragmentation pattern of compound 2 is illustrated in
Scheme 2. Quinazoline 2 can be considered as a cyclic
thiourea derivative and therefore can react with
chloroacetic acid as dielectrophiles in acetic acid/acetic
moiety fused with pyrane, pyridine and pyrazole to
evaluate the antifungal activity of them.
* Corresponding author. Fax: +20-88-325436.
E-mail address: m elgaby@hotmail.com (M.S.A. El-Gaby).
–
0014-827X/00/$ - see front matter © 2000 Published by Elsevier Science S.A. All rights reserved.
PII: S0014-827X(00)00042-2

288
S.M. Abdel-Gawad et al. / Il Farmaco 55 (2000) 287–292
anhydride in the presence of fused sodium acetate to
yield thiazoloquinazoline. Theoretically, two isomeric
cyclization products (3, 9H isomer; and 4, 5H isomer)
product 6 (Scheme 3). When the reaction of 2-aryl-
methylene (5a) with malononitrile was carried out in
methanol and sodium hydroxide, the pyrido[2%,3%:4,5]-
thiazolo[2,3-b]quinazoline (7) was formed, as estab-
lished from their elemental analysis and spectral data.
IR spectrum of 7 revealed the presence of CꢁN and
1
may be expected. The H NMR spectrum exhibited the
downfield of the thiazoloquinazoline H-5 in compound
4 (5H isomer) compared to the octahydroquinazoline
H-4, which appeared at l 6.00 ppm, indicate that a 5H
condensation product was obtained [13]. Refluxing of 4
with aromatic aldehydes in acetic acid/sodium acetate
furnished 2-arylmethylene derivatives 5a,b. Syntheses of
2-arylmethylene derivatives (5a,b) were achieved in a
single step by treating octahydroquinazoline (2) with
chloroacetic acid and aromatic aldehydes in the pres-
ence of sodium acetate, acetic acid and acetic anhydride
(Scheme 1).
Because of their a,b-unsaturated ketone moiety, thia-
zoloquinazolines (5) are convenient starting materials
for the synthesis of fused thiazoloquinazolines. Thus,
refluxing of equimolar amounts of 2-arylmethylenes
(5a,b) with malononitrile in the presence of ethanol and
piperidine furnished the corresponding pyrano-
[2%,3%:4,5]thiazolo[2,3-b]quinazolines (6a,b). The struc-
ture of 6 was established on the basis of analytical and
spectral data. Thus, the appearance of NH2, CꢁN and
CꢀO absorption bands in the IR spectra of the reaction
products corroborated the assigned structure 6. Also,
1H NMR spectrum of compound 6a exhibited a peak at
l 3.9 ppm and this could be attributed to pyran-4H.
The formation of 6 may proceed [14] via the initial
addition of malononitrile to exocyclic bond in 5 to yield
an acyclic intermediate, which may cyclize into final
1
CꢀO function and H NMR showed, in addition to the
aromatic signals, a methoxy signal at l 4.0 ppm. A
suggested mechanism for the formation of 6 is given in
Scheme 4. In the presence of sodium hydroxide, the
initially formed pyran 6 undergoes ring opening and
subsequent pyridine ring formation, the pyridine nitro-
gen being derived from the 2-amino group [15]. Also,
the pyrido[2%,3%:4,5]thiazolo[2,3-b]quinazoline (8) was
obtained through interaction of 5a with malononitrile
in the presence of ammonium acetate [14].
Refluxing of 2-arylmethylene (5a) with cyanothioac-
etamide in ethanol containing sodium ethoxide fur-
nished pyrido[2%,3%:4,5]thiazolo[2,3-b]quinazoline (9).
The study was also extended to investigate the be-
haviour of 2-arylmethylene against thiourea in the pres-
ence of base. Thus, the [1,3]thiazino[4%,5%:4,5]-
thiazolo[2,3-b]quinazoline (10) was synthesized by
refluxing of 2-aryl-methylene (5a) with thiourea in the
presence of potassium hydroxide [16]. It was reported
that [17], pyrazolines could be synthesized through
interaction of a,b-unsaturated carbonyl compounds
with hydrazines. Thus, when a,b-unsaturated ketone 5a
was treated with hydrazine or phenylhydrazine in
ethanol yielded the respective pyrazolo[3%,4%:4,5]-
thiazolo[2,3-b]quinazolines (11a,b) (Scheme 5).
Scheme 1.

S.M. Abdel-Gawad et al. / Il Farmaco 55 (2000) 287–292
289
Scheme 2. Fragmentation pattern of compound 2.
3. Experimental
3.2. 4-(4-Fluorophenyl)-3,6-dioxo-2,3,6,7,8,9-
hexahydro-5H-thiazolo[2,3-b]quinazoline (4)
All melting points are uncorrected. IR spectra were
recorded on a Shimadzu-440 IR spectrophotometer us-
ing the KBr technique (Shimadzu, Japan). H NMR
A mixture of 2 (0.01 mol), chloroacetic acid (0.01
mol), acetic anhydride (10 ml) in acetic acid (20 ml) was
1
spectra were measured on a Varian EM-360-90 MHz
spectrophotometer (Varian, UK) using TMS as an in-
ternal standard. The mass spectra were performed by a
Shimadzu-GC-MS-QP 100 EX (Shimadzu, Japan). Ele-
mental analyses were carried out by the Microanalytical
Research Centre, Faculty of Science, Cairo University.
Characteristics of the prepared compounds are given in
Table 1, analytical results for C, H, N were within
90.1% of the calculated values. The spectral data are
shown in Table 2.
3.1. 4-(4-Fluorophenyl)-5-oxo-1,2,3,4,5,6,7,8-
octahydroquinazolin-2-thione (2)
A mixture of 1,3-cyclohexanedione (1) (0.01 mol),
p-fluorobenzaldehyde (0.01 mol), thiourea (0.01 mol),
absolute ethanol (20 ml) and 36% HCl (3 ml) as heated
under reflux for an 4 h and the reaction mixture was
allowed to cool. The product, which appeared as a
precipitate, was filtered off and washed with ethanol
(Table 1).
Scheme 3.

290
S.M. Abdel-Gawad et al. / Il Farmaco 55 (2000) 287–292
The solid obtained was recrystallized from proper sol-
vent to give 5a,b (Table 1).
3.3.2. Method 2
A mixture of 2 (0.01 mol), chloroacetic acid (0.01
mol), required aromatic aldehydes (0.01 mol) in acetic
anhydride (10 ml) and acetic acid (20 ml) in the pres-
ence of fused sodium acetate (0.5 g) was refluxed for 2
h. The solid obtained was recrystallized from proper
solvent to give 5a,b.
3.4. 2-Amino-3-cyano-4-(4-substituted phenyl)-11-
(4-fluorophenyl)-10-oxo-7,8,9,10-tetrahydro-4H,11H-
pyrano[2%,3%:4,5]thiazolo[2,3-b]quinazolines (6a,b)
A mixture of 5a or 5b (0.01 mol), malononitrile (0.01
mol) in absolute ethanol (30 ml) containing piperidine
(0.5 ml) was refluxed for 3 h. The solid obtained
recrystallized from proper solvent to give 6a,b.
Scheme 4.
3.5. 2-Methoxy-3-cyano-4,11-bis-(4-fluorophenyl)-7,-
8,9,10-tetrahydro-11H-pyrido[2%,3%:4,5]thiazolo[2,3-b]-
quinazoline (7)
A mixture of 5a (0.01 mol) and malononitrile (0.01
mol) were dissolved in methanol (25 ml). Crushed
sodium hydroxide (0.2 g) was added and the reaction
mixture was stirred under reflux for 10 h. The
precipitated product was filtered, washed with water
and recrystallized from proper solvent to give 7 (Table
1).
3.6. 2-Amino-3-cyano-4,11-bis-(4-fluorophenyl)-
7,8,9,10-tetrahydro-11H-pyrido[2%,3%:4,5]thiazolo[2,3-b]-
quinazolin (8)
Amixtureof5a(0.01mol),malononitrile(0.01mol)and
ammonium acetate (1 gm) in absolute ethanol (30 ml)
Table 1
Analytical data for the synthesized compounds
Scheme 5.
Comp. Solvent
crystal
Yield (%) M.p. (°C) Molecular formula (Mw)
refluxed for 4 h. The solid obtained was recrystallized
from proper solvent to give 4 (Table 1).
2
4
ethanol
84
275–277 C14H13FN2OS (276)
224–225 C16H13FN2O2S (316)
230–232 C23H16F2N2O2S (422)
235–236 C23H16ClFN2O2S (438.5)
236–238 C26H18F2N4O2S (488)
185–186 C26H18ClFN4O2S (504.5)
108–110 C27H18F2N4O2S (500)
125–126 C26H17F2N5OS (485)
acetic acid 90
acetic acid 78
acetic acid 76
5a
5b
6a
6b
7
8
9
10
11a
11b
3.3. 2-(4-Substituted phenyl)-5-(4-fluorophenyl)-3,6-
dioxo-2,3,6,7,8,9-hexahydro-5H-thiazolo[2,3-b]-
quinazoline (5a,b)
ethanol
ethanol
ethanol
ethanol
ethanol
dioxane
dioxane
dioxane
60
64
53
80
60
60
73
78
\300
C26H16F2N4OS2 (502)
3.3.1. Method 1
220–222 C24H18F2N4OS2 (480)
272–274 C23H18F2N4OS (436)
282–281 C29H22F2N4OS (512)
A mixture of 4 (0.01 mol), required aromatic alde-
hydes (0.01 mol) in acetic acid (20 ml) in the presence
of fused sodium acetate (0.5 g) was refluxed for 2 h.

S.M. Abdel-Gawad et al. / Il Farmaco 55 (2000) 287–292
291
Table 2
Spectral data for the synthesized compounds
Comp.
IR (KBr)
1H NMR (l ppm) (in DMSO-d6)
2
3280, 3200 cm−1 (NH); 1700 cm−1 (CꢀO); 1500,1220 cm−1
(–CꢀS; amide II and amide I)
1.8–2.5 (6H, m, CH2-6, CH2-7, CH2-8); 5.2 (1H, d, CH-4);
7.2–7.8 (4H, m, Ar–H); 9.72 (1H, s, N1–H; exchangeable),
10.72 (1H, s, N3–H; exchangeable)
1.9–2.57 (6H, m, CH2-7, CH2-8,CH2-9); 3.40 (2H, s, CH2-2);
6.00(1H, s, CH-5), 7.41–7.85 (4H, m, Ar–H)
4
1690, 1680 cm−1 (2CꢀO)
5a
5b
6a
2950 cm−1 (CH-aliphatic); 1710 cm−1 (CꢀO); 1660 cm−1
(CꢀO; thiazole ring)
2900 cm−1 (CH-aliphatic); 1708 cm−1 (CꢀO); 1680 cm−1
(CꢀO)
1.7–2.60 (6H, m, CH2-7, CH2-8, CH2-9); 6.00 (1H, s, CH-4);
7.15–8.0 (9H, m, Ar–H+CH-2)
1.65–2.58 (m, 6H, CH2-7, CH2-8, CH2-9); 3.00 (2H, s, NH2;
exchangeable); 3.9 (1H, s, CH-4);6.1 (1H, s, CH-11); 7.10–7.7
(8H, m, Ar–H)
3450, 3350 cm−1 (NH2); 2950 cm−1 (CH-aliphatic); 2205
cm−1(CꢁN); 1700 cm−1 (CꢀO)
6b
7
3400, 3450 cm−1 (NH2); 2900 cm−1 (CH-aliphatic); 2200 cm−1
(CꢁN); 1680 cm−1 (CꢀO)
2980 cm−1 (CH-aliphatic); 2200 cm−1 (CꢁN); 1680 cm−1
(CꢀO)
1.80–2.57 (6H, m, CH2-7, CH2-8, CH2-9); 4.0 (3H, s, OCH3),
5.7 (1H, s, CH-11); 7.0–7.7 (8H, m, Ar–H)
8
3336, 3217 cm−1 (NH2); 3069 cm−1 (CH-aromatic); 2945 cm−1 1.70–2.41 (6H, m, CH2-7, CH2-8, CH2-9); 4.10 (2H, s, NH2;
(CH-aliphatic); 2208 cm−1 (CꢁN); 1664 cm−1 (CꢀO)
3415 cm−1 (NH); 2910 cm−1 (CH-aliphatic); 2217 cm−1
(CꢁN); 1665 cm−1 (CꢀO)
exchangeable), 6.10 (1H, s, CH-11), 7.1–7.81 (8H, m, Ar–H)
1.62–2.50 (6H, m, CH2-7, CH2-8, CH2-9); 6.00 (1H, s, CH-11);
7.20–7.90 (8H, m, Ar–H); 9.4 (1H, s, NH; exchangeable)
9
10
3400, 3300 cm−1 (2NH); 2900 cm−1 (CH-aliphatic); 1700 cm−1 1.9–2.51 (6H, m, CH2-7, CH2-8, CH2-9); 5.1 (1H, s, CH-4); 5.5
(CꢀO)
(1H, s, CH-11); 7.0–7.6 (8H, m, Ar–H); 8.9 (1H, s, NH;
exchangeable), 9.8 (1H, s, NH; exchangeable)
11a
11b
3353 cm−1 (NH); 3060 cm−1 (CH-aromatic); 2941 cm−1
(CH-aliphatic);1671 cm−1 (CꢀO)
3051 cm−1 (CH-aromatic); 2922 cm−1 (CH-aliphatic); 1668
cm−1 (CꢀO)
and the reaction mixture was refluxed for 3 h. The solid
product was filtered off and recrystallized from proper
solvent to give 8 (Table 1).
was refluxed for 3 h. It was then cooled and the
resulting solid was recrystallized from proper solvent to
give 11a,b (Table 1).
Mass spectrum of 11a exhibited a molecular ion peak
at m/z 436 (3.56%) together with a base peak at m/z 57.
Other significant peaks were observed at m/z: 414
(3.37%), 387 (5.1%), 353 (7.89%), 285 (7.89%), 285
(18.86%), 237 (15.5%), 209 (10.39%), 170 (12.9%), 138
(23.29), 9.9 (20.21%) and 71 (40.90).
3.7. 3-Cyano-4,11-bis-(4-fluorophenyl)-
1,2,7,8,9,10-hexahydro-11H-pyrido[2%,3%,4,5]-
thiazolo[2,3-b]quinazolin-2-thione (9)
A mixture of compound 5a (0.01 mol), cyanothioac-
etamide (0.01 mol) and sodium ethoxide (0.01 mol) in
ethanol (30 ml) was refluxed for 2 h. The product
formed was collected and recrystallized from proper
solvent to give 9 (Table 1).
3.10. Antifungal acti6ity
The search for antifungal activity was carried out by
the microbiology laboratory at the Faculty of Science,
Al-Azhar University, Cairo, Egypt.
3.8. 4,11-Bis(4-fluorophenyl)-
1,2,7,8,9,10-hexahydro-2-imino-4H,11H-[1,3]-
thiazino[4%,5%:4,5]thiazolo[2,3-b]-quinazoline (10)
Some of the newly synthesized compounds were
tested for their antifungal activity against four species
of fungi, namely; Aspergillus ochraceus Wilhelm
(AUCC-230), Penicillium chrysogenum Thom (AUCC-
530), Aspergillus fla6us Link (AUCC-164) and Candida
albicans (Robin) Berkho (AUCC-1720), using the disc
diffusion method [18,19].
A mixture of 5a (0.01 mol), thiourea (0.01 mol) and
potassium hydroxide (0.02 mol) was refluxed in ethanol
for 2 h. On cooling it was acidified with dilute HCl. The
resulting solid product was washed with water and
recrystallized from proper solvent to give 10 (Table 1).
3.9. Pyrazolo[3%,4%:4,5]thiazolo[2,3-b]quinazolines
(11a,b)
The tested compounds were dissolved in N,N-
dimethylformamide (DMF) to get a solution of 1%
concentration. Filter paper discs (Whatman No. 3 filter
paper, 5 mm diameter) were saturated with this former
solution. The saturated filter paper discs were placed on
A solution of 5a (0.01 mol), and hydrazine hydrate or
phenyl hydrazine (0.02 mol) in absolute ethanol (50 ml)

292
S.M. Abdel-Gawad et al. / Il Farmaco 55 (2000) 287–292
Table 3
Antifungal activity of the synthesized compounds a
Comp.
Aspergillus ochraceus Wilhelm Penicillium chrysogenum Thom Aspergillus fla6us Link
Candida albicans (Robin) Berkho
(AUCC-230)
(AUCC-530)
(AUCC-164)
(AUCC-1720)
4
+
+++
+++
+++
+
++
+
+
+
5b
6b
7
8
10
11
++
++
++
+++
+
++
++
++
++
+
+++
+++
++
++
+
+
+
++++
+
++++
+
++++
Trosyd b ++++
a +, 1–1.5 cm; ++, 1.6–2 cm; +++, 2.1–3 cm; ++++, \3 cm.
b Manufactured by Pfizer-Egypt, S.A.E., Cairo, A.R.E. under authority of Pfizer Inc., USA.
potential pharmacological interest, J. Chem. Soc. (1963) 2256.
[6] A.J. Barker, Preparation of 4-anilinoquinazolines as anticancer
agents, Eur. Patent 635498 (1995) [Chem. Abstr. 122 (1995)
214 099a].
[7] A.A. Bekhit, M.A. Khalil, Non-steroidal antiinflammatory
agents: synthesis of novel benzopyrazolyl, benzoxazolyl and
quinazolinyl derivatives of 4(3H)-quinazolinones, Pharmazie 53
(1998) 539.
the surface of solidified Czapek’s Dox agar dishes
seeded by the test fungi. The inhibition zones were
measured in millimetres at the end of an incubation
period of 48 h at 28°C. The results are shown Table 3.
The minimal inhibitory concentration (MIC) values
for the biological active compounds 4, 5b, 6b and 8
were determined by the serial dilution method [20].
Trosyd (Tioconazole) was used as a reference drugs to
evaluate the potency of the tested compounds.
[8] N.S. Habib, S.A. El-Hawash, Synthesis and antimicrobial testing
of thiazolinyl-, thiazolidinonylquinoxalines and 1,2,4-tria-
zolo[4,3-a]quinoxalines, Pharmazie 52 (1997) 594.
[9] J.S. Shukla, R. Shukla, Synthesis of 4-(5-substituted-arylidine-4-
thiazolidinone-2-thione)-6,8-substituted quinazolines as potential
anthelmintic agents, J. Indian Chem. Soc. 66 (1989) 209.
[10] M. Malesic, A. Krbovcic, A. Golobio, L. Golic, B. Stanovnik,
The synthesis and transformation of some 3-thiocarbamoylthia-
zolidines, J. Heterocyclic Chem. 34 (1997) 43.
4. Antifungal activity
The results (Table 3) showed that compounds 4, 5b
and 6b possess high activity against Penicillium chryso-
genum Thom (AUCC-530) (MIC 100 mg ml−1); com-
pound 8 showed a high activity against Aspergillus
ochraceus Wilhelm (AUCC-230). Also, compounds 5b
and 6b revealed the high activity against Candida albi-
cans (Robin) Berkho (AUCC-1720). MIC values for the
biological active compounds 4, 5b, 6b and 8 were 100
mg ml−1, all these compounds are less active than
reference drug (Trosyd).
[11] L.A. McDonald, M.P. Foster, D.R. Phillips, C.M. Ireland,
Towicyclamides A and B, new cyclic peptides from the ascidian
lissoclinum patella: studies on the solution and solid state con-
formations, J. Org. Chem. 57 (1992) 4616.
[12] S. Sarac, M. Yarim, M. Ertan, S. Boydag, K. Erol, Synthesis,
chemical and pharmacological properties of some 4-aryl-
1,2,3,4,5,6,7,8-octahydroquinazoline-2,5-diones, Pharmazie 53
(1997) 91.
[13] B. Tozkoparan, H. Akgun, M. Ertan, K. Rubsemann, Con-
densed heterocyclic compounds: synthesis and antiinflammatory
activity of novel thiazolo[3,2-a]pyrimidines, Arch. Pharm.
(Weinheim) 321 (1998) 201.
[14] H.A. Daboun, A.M. AbdFattah, M.A. Abdaziz, Reactions with
thiazolo[3,2-a]benzimidazol-3-one derivatives: a novel synthesis
of pyrano- and pyrido[2,3:4%,5]thiazolo[2,3-a]benzimidazole
derivatives, Egypt J. Chem. 27 (1984) 435 [Chem. Abstr. 106
(1987) 102 156e].
References
[15] E.T. McCarthy, D.V. Tyndall, M.J. Meegan, A new synthesis of
pyrido[3,2-a]benzothiazines, J. Chem. Res. (S) (1988) 145; J.
Chem. Res. (M) (1988) 1332.
[1] G. Honda, M. Tabata, M. Tsuda, The antimicrobial specificity
of tryptanthrin, Plant. Med. 37 (1979) 172.
[2] N.B. Chapman, G.M. Gibson, F.G. Mann, Synthetic antimalar-
ials. Part XVI. 4-dialkylaminoalkylaminoquinazolines. Variation
of substituents in 6- and 7- positions, J. Chem. Soc. (1947) 890.
[3] S.G. Abdel-Hamide, A.E. El-Hakim, A.A. El-Helby, Synthesis
[16] D. Dwivedi, N. Tiwari, Synthesis of some 1-aroyl-3-methyl-4-
substituted
phenyl-6-imino-4,7-dihydro-1,3-thiazino[5,4-d]-
pyrazoles as pesticides, J. Indian Chem. Soc. 68 (1991) 515.
[17] R.A. Kabli, A.A. Khalaf, M.T. Zimaity, A.M. Khalil, A.M.
Kaddah, H.A. Al-Rifaie, Synthesis of a new series of furyl and
thienyl substituted pyrazolines starting with furyl and thienyl
chalcones, J. Indian Chem. Soc. 68 (1991) 47.
of
2-[1-(5-ethyl-5-phenyl)barbituryl]methylcarbonylthioquina-
zoline-4-one for hypnotic and anticonvulsant activities, Az. J.
Pharm. Sci. 17 (1996) 35.
[4] G.E. Hardtmann, H. Ott, Stimulant and antidepressant 4-(sub-
stituted amino)quinazolines, U.S. Patent 3470182 (1969) [Chem.
Abstr. 72 (1970) 90 502d].
[5] N.B. Chapman, K. Clarke, K. Wilson, Synthesis of N,N-dialkyl-
N%-arylalkyl-N-4-cinnolinyl (or 9-fluorenyl or 6-methyl-3-pyri-
dazinyl or 1-phthalazinyl or 2-quinoxalinyl)ethylenediamines of
[18] L.P. Carrod, F.D. Grady, Antibiotic and Chemotherapy, third
ed., Churchill Livingstone, Edinburgh, 1972, p. 477.
[19] A. Cremer, Antibiotic Sensitivity and Assay Tests, fourth ed.,
Butterworth, London, 1980, p. 521.
[20] P. Courvalin, Interpretive reading of antimicrobial susceptibility
tests, Am. Soc. Microbiol. News 58 (1992) 368–375.