Papers by Mohammad Emad azab
Isothiazolopyridines, pyridothiazines and pyridothiazepines are important compounds that possess ... more Isothiazolopyridines, pyridothiazines and pyridothiazepines are important compounds that possess valuable biological activities. This paper reports on the synthesis of these compounds using both conventional chemical methods and
Aiming for the synthesis of new heterocyclic compounds containing a sulfonamido moiety suitable f... more Aiming for the synthesis of new heterocyclic compounds containing a sulfonamido moiety suitable for use as antibacterial agents, the precursor ethyl {[4-N-(4,6-dimethylpyrimidin-2-yl)sulfamoyl]phenylazo}cyanoacetate was reacted with a variety of active methylene compounds producing pyran, pyridine and pyridazine derivatives. Also, the reactivity of the precursor hydrazone towards hydrazine derivatives to give pyrazole and oxazole derivatives was studied. On the other hand, treatment of the same precursor with urea, thiourea and/or guanidine hydrochloride furnished pyrimidine and thiazine derivatives, respectively. The newly synthesized compounds were tested for antibacterial activity, whereby eight compounds were found to have high activities.
—A series of tetrapeptide Schiff bases and a macrocyclic pentapeptide were synthesized using N α-... more —A series of tetrapeptide Schiff bases and a macrocyclic pentapeptide were synthesized using N α-dinicotinoyl-bis[L-leucyl-L-phenylalaninyl acid hydrazide] derivative and macrocyclic pentapeptide ester as starting materials and were screened for antimicrobial activity. Some of the newly synthesized compounds exhibited better antimicrobial effect compared to the reference controls. The structures of the newly synthesized compounds were confirmed by IR, NMR, and mass spectral data and elemental analyses.
Treatment of 2,3-diaryloxirane-2,3-dicarbonitriles 1a–c with different nitrogen
nucleophiles, e.g... more Treatment of 2,3-diaryloxirane-2,3-dicarbonitriles 1a–c with different nitrogen
nucleophiles, e.g., hydrazine, methyl hydrazine, phenyl hydrazine, hydroxylamine,
thiosemicarbazide, and/or 2-amino-5-phenyl-1,3,4-thiadiazole, afforded pyrazole,
isoxazole, pyrrolotriazine, imidazolothiadiazole derivatives 2–5, respectively. Reacting
pyrazoles 2a–c with aromatic aldehydes and/or methyl glycinate produced Schiff’s bases
7a–d and pyrazolo[3,4-b]-pyrazinone derivative 8, respectively. Treating 7 with
ammonium acetate and/or hydrazine hydrate, furnished the imidazolopyrazole and
pyrazolotriazine derivatives 9 and 10, respectively. Reaction of 8 with chloroacetic acid
and/or diethyl malonate gave tricyclic compound 11 and triketone 12, respectively. On the
other hand, compound 1 was reacted with active methylene precursors, e.g., acetylacetone
and/or cyclopentanone producing adducts 14a,b which upon fusion with ammonium
acetate furnished the 3-pyridone derivatives 15a,b, respectively. Some of newly
synthesized compounds were screened for activity against bacterial and fungal strains and
most of the newly synthesized compounds showed high antimicrobial activities. The
structures of the new compounds were elucidated using IR, 1H-NMR, 13C-NMR and
mass spectroscopy.
Reactions of 6-bromo-2-isopropyl-4(3H)-3,1-benzoxazin-4-one toward mono- and di-dentate nitrogen
... more Reactions of 6-bromo-2-isopropyl-4(3H)-3,1-benzoxazin-4-one toward mono- and di-dentate nitrogen
nucleophiles, e.g. primary aliphatic and aromatic amines, 1,2-phenylenediamine, hydrazine hydrate, and
formamide, have been investigated and afford the corresponding quinazolinones which are expected to have
some interesting biological activity. The behavior of 3, 1-benzoxazin-4-one toward active methylene compounds,
namely, acetylacetone in basic medium has been studied and gave 3-acetylquinoline. The last reaction
is considered as an illustrative model of heterocyclic transformation reactions.
An acetylhydrazide derivative containing a quinazoline nucleus has been utilized to design and sy... more An acetylhydrazide derivative containing a quinazoline nucleus has been utilized to design and synthesize a series of 2,4-disubstituted quinazolines via reaction with several carbon electrophiles including 4-methoxybenzaldehyde and carbon disulfide as well as acetyl and benzoyl chloride. Another series of 2,3-disubstituted-4(3H)-quinazolinones has been also obtained from reactions of a 3-aminoquinazolin-4(3H)-one derivative with other carbon electrophiles, such as chloroacetamide, acetic anhydride, phenyl isocyanate, and ethyl chloroacetate. The structures of the new compounds have been assigned from their spectral data (IR, 1 H NMR, 13 C NMR and MS) and elemental analyses. The newly synthesized compounds were evaluated for their in vitro cytotoxic activity against breast cancer, hepatocellular carcinoma, cervical cancer, and human promyelocytic leukemia cell lines. All the tested compounds showed anticancer activity.
Benzoxazinones and quinazolinones have a wide spectrum of biological activity. In this paper we f... more Benzoxazinones and quinazolinones have a wide spectrum of biological activity. In this paper we focused on studying the antimicrobial and anti-inflammatory activities of some newly synthesized benzoxazinone and quinazolinone derivatives. Thus we prepared 2-[α-benzoylaminostyryl]-6,8-dibromo-3,1-benzoxazin-4(H)-one 2 which underwent a reaction with primary and secondary amines, and hydrazine hydrate to give compounds 3, 4 and 5, respectively. Treatment of 2 with hydroxylamine hydrochloride, formamide and/or NaN 3 / AcOH afforded compounds 7, 8, 11 and 12, respectively. Also, compound 2 reacted with maleic anhydride, aromatic hydrocarbons and/or active methylene compounds to produce compounds 13, 15a–c and 16, respectively. Most of the newly synthesized compounds showed significant antimicrobial and anti-inflammatory activities comparable to ampicillin, mycostatine and indomethacin positive controls.
The present work describes convenient synthesis of the novel Schiff bases 5a and b by reacting ph... more The present work describes convenient synthesis of the novel Schiff bases 5a and b by reacting phthala-zinones 4a and b with 4-methoxybenzaldehyde Reaction of the Schiff bases with phenylisothiocyanate afforded diazetidine derivatives 7a and b. Also, compounds 4a and b reacted with 2-bromoglucoside tetraacetate giving peracetylated N-glycosides 6a and b, which were deacetylated to afford N-glycosylated phthalazinones 8a and b. On the other hand, when compound 3 was treated with POCl 3 /PCl 5 and/or ethyl chloroacetate, chlorophthalazine and ethyl acetate derivatives 9 and 10 were obtained, respectively. Hydrazinolysis of compounds 9 and 10 produced the hydrazino and hydrazide derivatives 11 and 12, respectively. When compound 11 reacted with 2-furanaldehyde, acetic anhydride, and/or carbon disulphide, it gave compounds 13–15, respectively. Treatment of the hydrazide 12 with aromatic aldehydes, acetic anhydride, ethyl acetoacetate, acetyl acetone, ammonium thiocyanate, and/or phthalic anhydride furnished compounds 17–21. Meanwhile, reacting Schiff base 22 with the chlorophthalazine derivative 9 produced compound 23, which on treatment with furoyl chloride produced compound 24. The structures of the novel compounds were confirmed by IR, 1 H-NMR, 13 C-NMR, MS, and elemental analysis. The newly synthesized compounds were tested against Bacillus subtilis and Staphylococcus aureus as Gram-positive bacteria, Escherichia coli and Pseudomonas au-rignosa as Gram-negative bacteria, and Candida albicans and Aspergillus niger as fungi strains. Compounds 5a and b, 23, and 24 showed greater antimicrobial activity than the stranded compounds, suggesting that they could be considered as promising antimicrobial agents.
CHEMICAL & PHARMACEUTICAL BULLETIN, 2016
Benzoxazinones and quinazolinones have a wide spectrum of biological activity. In this paper we f... more Benzoxazinones and quinazolinones have a wide spectrum of biological activity. In this paper we focused on studying the antimicrobial and anti-inflammatory activities of some newly synthesized benzoxazinone and quinazolinone derivatives. Thus we prepared 2-[α-Benzoylaminostyryl]-6,8-dibromo-3,1-benzoxazin-4(H)-one 2 which underwent a reaction with primary and secondary amines, and hydrazine hydrate to give compounds 3, 4 and 5, respectively. Treatment of 2 with hydroxylamine hydrochloride, formamide and/or NaN3/AcOH afforded compounds 7, 8, 11 and 12, respectively. Also, compound 2 reacted with maleic anhydride, aromatic hydrocarbons and/or active methylene compounds to produce compounds 13, 15a-c and 16, respectively. Most of the newly synthesized compounds showed significant antimicrobial and anti-inflammatory activities comparable to ampicillin, mycostatine and indomethacin positive controls.
ChemInform, 1994
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Molecules, 2013
Aiming for the synthesis of new heterocyclic compounds containing a sulfonamido moiety suitable f... more Aiming for the synthesis of new heterocyclic compounds containing a sulfonamido moiety suitable for use as antibacterial agents, the precursor ethyl {[4-N-(4,6dimethylpyrimidin-2-yl)sulfamoyl]phenylazo}cyanoacetate was reacted with a variety of active methylene compounds producing pyran, pyridine and pyridazine derivatives. Also, the reactivity of the precursor hydrazone towards hydrazine derivatives to give pyrazole and oxazole derivatives was studied. On the other hand, treatment of the same precursor with urea, thiourea and/or guanidine hydrochloride furnished pyrimidine and thiazine derivatives, respectively. The newly synthesized compounds were tested for antibacterial activity, whereby eight compounds were found to have high activities.
Phosphorus, Sulfur, and Silicon and the Related Elements, 2001
The reaction of 5-spirocyclohexylimidazole-2,4-dithion with one and two mole equivalent of β-amin... more The reaction of 5-spirocyclohexylimidazole-2,4-dithion with one and two mole equivalent of β-aminocarboxylic acid derivatives (2a-b and 5) to give new heterocyclic systems of synthetic and potential biological interest viz, compounds (3a-b, 4a-b, 6 and 7). The structures of the products have established by chemical and spectroscopic evidence. The antimicrobial activity of the synthesized compounds was tested against 10 bacterial and
Phosphorus Sulfur and Silicon and The Related Elements, 2009
Phosphorus Sulfur and Silicon and The Related Elements, 2008
... Chem. , 35: 351 [CrossRef], [PubMed], [Web of Science ®] View all references In addition to t... more ... Chem. , 35: 351 [CrossRef], [PubMed], [Web of Science ®] View all references In addition to the above mentioned activities, thienopyrimidine derivatives have antimicrobial, 7 7. Moneer, AA 2001. Bull. ... Azab, ME, El-Hag Ali, GAM and Abdel-Wahab, AF 2003. Acta Chem. Pharm. ...
Synthesis of New Thiadiazoles, 1,2,4-Triazolo[3,4-b]-1,3,4-thiadiazoles, and 1,2,4-Triazolo[2,3-c]quinazoline Derivatives from 3,1-Benzoxazin(4H)-one Derivative Phosphorus Sulfur and Silicon and The Related Elements, 2007
3,1-benzoxazin-4H-one derivative was reacted with Grignard reagents, primary and secondary amines... more 3,1-benzoxazin-4H-one derivative was reacted with Grignard reagents, primary and secondary amines, glycine, hydrazine hydrate, azines, and Schiff's base. The acid hydrazide derivative was the key starting material for the synthesis of triazole, triazolo[3,4-b]thiadiazole, thiadiazole, and triazolo[2,3-c]quinazoline.
Cheminform, 2010
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Synthetic Communications, 2002
ABSTRACT
Phosphorus Sulfur and Silicon and The Related Elements, 2006
... Pat. 144,101. 1985. View all references antiallergic, 3 5. Vingoardoff, AP, Peet, NP and Sund... more ... Pat. 144,101. 1985. View all references antiallergic, 3 5. Vingoardoff, AP, Peet, NP and Sunder, S. Eur. Pat. 234,557. 1987. ... An equimolar mixture of 4,5,6,7-tetrahydrobenzo[b]thieno[2,3-d]- pyrimidin-4(3H)-one 28 34. Ram, VJ, Pandy, HK and Vlietinck, A. 1981. J. Het. Chem. ...
Tetrahedron, 2009
A general route to the ABC ring system of phenanthridone alkaloids is available by acylation of... more A general route to the ABC ring system of phenanthridone alkaloids is available by acylation of 2-oxa-zolone with a 2-butadienylbenzoic acid derivative, followed by an intramolecular DielsAlder reaction and hydrolysis.
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Papers by Mohammad Emad azab
nucleophiles, e.g., hydrazine, methyl hydrazine, phenyl hydrazine, hydroxylamine,
thiosemicarbazide, and/or 2-amino-5-phenyl-1,3,4-thiadiazole, afforded pyrazole,
isoxazole, pyrrolotriazine, imidazolothiadiazole derivatives 2–5, respectively. Reacting
pyrazoles 2a–c with aromatic aldehydes and/or methyl glycinate produced Schiff’s bases
7a–d and pyrazolo[3,4-b]-pyrazinone derivative 8, respectively. Treating 7 with
ammonium acetate and/or hydrazine hydrate, furnished the imidazolopyrazole and
pyrazolotriazine derivatives 9 and 10, respectively. Reaction of 8 with chloroacetic acid
and/or diethyl malonate gave tricyclic compound 11 and triketone 12, respectively. On the
other hand, compound 1 was reacted with active methylene precursors, e.g., acetylacetone
and/or cyclopentanone producing adducts 14a,b which upon fusion with ammonium
acetate furnished the 3-pyridone derivatives 15a,b, respectively. Some of newly
synthesized compounds were screened for activity against bacterial and fungal strains and
most of the newly synthesized compounds showed high antimicrobial activities. The
structures of the new compounds were elucidated using IR, 1H-NMR, 13C-NMR and
mass spectroscopy.
nucleophiles, e.g. primary aliphatic and aromatic amines, 1,2-phenylenediamine, hydrazine hydrate, and
formamide, have been investigated and afford the corresponding quinazolinones which are expected to have
some interesting biological activity. The behavior of 3, 1-benzoxazin-4-one toward active methylene compounds,
namely, acetylacetone in basic medium has been studied and gave 3-acetylquinoline. The last reaction
is considered as an illustrative model of heterocyclic transformation reactions.
nucleophiles, e.g., hydrazine, methyl hydrazine, phenyl hydrazine, hydroxylamine,
thiosemicarbazide, and/or 2-amino-5-phenyl-1,3,4-thiadiazole, afforded pyrazole,
isoxazole, pyrrolotriazine, imidazolothiadiazole derivatives 2–5, respectively. Reacting
pyrazoles 2a–c with aromatic aldehydes and/or methyl glycinate produced Schiff’s bases
7a–d and pyrazolo[3,4-b]-pyrazinone derivative 8, respectively. Treating 7 with
ammonium acetate and/or hydrazine hydrate, furnished the imidazolopyrazole and
pyrazolotriazine derivatives 9 and 10, respectively. Reaction of 8 with chloroacetic acid
and/or diethyl malonate gave tricyclic compound 11 and triketone 12, respectively. On the
other hand, compound 1 was reacted with active methylene precursors, e.g., acetylacetone
and/or cyclopentanone producing adducts 14a,b which upon fusion with ammonium
acetate furnished the 3-pyridone derivatives 15a,b, respectively. Some of newly
synthesized compounds were screened for activity against bacterial and fungal strains and
most of the newly synthesized compounds showed high antimicrobial activities. The
structures of the new compounds were elucidated using IR, 1H-NMR, 13C-NMR and
mass spectroscopy.
nucleophiles, e.g. primary aliphatic and aromatic amines, 1,2-phenylenediamine, hydrazine hydrate, and
formamide, have been investigated and afford the corresponding quinazolinones which are expected to have
some interesting biological activity. The behavior of 3, 1-benzoxazin-4-one toward active methylene compounds,
namely, acetylacetone in basic medium has been studied and gave 3-acetylquinoline. The last reaction
is considered as an illustrative model of heterocyclic transformation reactions.