Said Ahmed Soliman Ghozlan

β-Amino-β-(pyrid-4-yl)acrylonitrile in heterocyclic synthesis: synthesis of some new pyridine, pyridone, pyrazole, thiophene, fused pyrimidine and triazine derivatives

Abstract β-Amino-β-(pyrid-4-yl)acrylonitrile reacts with various types of reagents with variable molar ratios under different conditions to yield pyridine derivatives and condensed heterocyclic compounds containing a pyridyl moiety.

Reactions with heterocyclic amidines, VII: Synthesis of some new pyrazolo[1,5-c]-1,2,4-triazines, pyrazolo[1,5-a]-1,3,5-triazines and pyrazolo[1,5-a]pyrimidines

Diazotised 5-amino-3-methyl-4-phenyloyrazole (1) reacted with active methylene reagents and with β-naphthol to yield the pyrazolo[1,5-c)-1,2,4-triazine derivatives2a-e and5. Compound1 reacted with benzoyl isothiocyanate and with phenyl isothiocyanate to yield the corresponding pyrazol-5-ylthiourea derivatives6a, b. 5a was converted into the thiourea derivative8 by the action of acids or alkalies. A synthesis of 2-methyl-3-phenyl-4,5,6,7-tetrahydropyrazolo[1,5-a]-pyrimidin-5-one from the reaction of α-phenylacetoactonitrile (3-oxo-2-phenyl-butyric nitrile) and β-cyanoethylhydrazine is reported.ZusammenfassungDiazotiertes 5-Amino-3-methyl-4-phenylpyrazol (1) reagiert mit einer aktiven Methylenkomponente und β-Naphthol zu den Pyrazolo[1,5-c]-1,2,4-triazin-Derivaten2a-e und5. 1 ergibt mit Benzoylisothiocyanat und Phenylisothiocyanat die entsprechenden Pyrazol-5-yl-thioharnstoffe6a, b. 5a wurde mittels Säure oder Base in das Thioharnstoffderivat8 umgewandelt. Es wird über eine Synthese von 2-Methyl-3-phenyl-4,5,6,7-tetrahydropyrazolo[1,5-a]-pyrimidin-5-on aus α-Phenylacetoacetonitril (3-Oxo-2-phenyl-butyronitril) und β-Cyanoethylhydrazin berichtet.

Cytotoxic and Antimicrobial Evaluations of Novel Apoptotic and Anti‐Angiogenic Spiro Cyclic 2‐Oxindole Derivatives of 2‐Amino‐tetrahydroquinolin‐5‐one

A novel series of cyclic 2‐oxindole derivatives incorporating 2‐amino‐tetrahydroquinolin‐5‐one were prepared. The structures of the prepared compounds were elucidated using different spectral tools. The regio‐orientation of the reaction products was elucidated through NOE difference experiments and through using substituents on the ortho position to affect further cyclization. Antitumor and antimicrobial evaluations were performed on the prepared compounds. Most of these compounds exhibited high to moderate antimicrobial activity. With respect to the antitumor activity, the compounds showed more potent cytotoxic effect only toward the human breast cancer cell line MCF‐7. Also, we found that derivatives containing an ester group (8c, 11b, 14b, and 15b) are more active than those containing a cyanide group (8a, 11a, 14a, and 15a). Moreover, compounds 15b and 8b are the most active derivatives in this group. These two compounds showed apoptotic inhibition of the proliferation of human breast adenocarcinoma MCF‐7 cells through DNA fragmentation, induction of the tumor suppressor protein p53, induction of caspase‐9, and finally the inhibition of angiogenesis by decreasing vascular endothelial growth factor expression and secretion.

Studies on 5-aminopyrazole derivatives synthesis of some new fused pyrazole derivatives

5-Amino-4-cyano-3-phenylpyrazole (1) reacts with acrylonitrile or ethyl acrylate to yield 4-cyano-3-phenyl-4,5,6,7-tetrahydro-5-oxopyrazolo-[1,5-a]-pyrimidine (2). With urea, thiourea and ethyl acetoacetate1 gives the pyrazolopyrimidine derivatives6a,6b, and7 respectively. On the other hand, compound1 reacted with benzoylisothiocyanate to give the corresponding thiourea derivative4. Diazotized1 was coupled with malononitrile and ethyl cyanoacetate to yield the pyrazolopyrimidine derivatives10 and11, respectively, whereas on coupling with α-chloro acetoacetic ester and with acetylacetone the hydrazones12 and13 were obtained.

An easy synthesis of 5-functionally substituted ethyl 4-amino-1-aryl- pyrazolo-3-carboxylates: interesting precursors to sildenafil analogues

3-Oxo-2-arylhydrazononitriles 1a-c react readily with chloroacetonitrile, ethyl chloroacetate, and with phenacyl chloride to give 4-aminopyrazoles 4a-e. The pyrazolo[4,3-d]pyrimidine derivatives 7 and 10 are synthesized via reaction of the aminopyrazole 4b with phenylisothiocyanate and DMFDMA/NH4OAc respectively.

Synthesis and Antimicrobial Evaluations of Novel Spiro Cyclic 2-Oxindole Derivatives of N-(1H-Pyrazol-5-Yl)-Hexahydroquinoline Derivatives

A novel series of interesting spiro cyclic 2-oxindole derivatives of N-(1H-pyrazol-5-yl)hexahydroquinoline derivatives were prepared via the versatile readily accessible cyclic β-enaminones incorporating pyrazole. Antimicrobial evaluations were performed on the prepared compounds. Most of these compounds exhibited high to moderate antimicrobial activity.

Nitriles in Heterocyclic Synthesis: Novel Syntheses of Functionally Substituted Isoxazoles, Pyrazoles, Pyrazines and their Condensed Derivatives

Novel syntheses of functionally substituted isoxazoles, pyrazoles and pyrazines have been reported utilizing ethyl tosyloximinoglyoxalate (1) and the pyridinium salt 2 as starting materials. Functionally substituted nitriles are versatile reagents and their utility in heterocyclic synthesis has received considerable recent attention [3 - 7]. In previous work we have reported several new approaches for the synthesis of azoles, azines and azoloazines utilizing simple readily obtainable polyfunctional nitriles as starting materials [8-12]. Although 1 and 2 can be readily prepared from ethyl cyanoacetate, however, their utility in synthesis of heterocycles has received only very little attention [1, 2, 13-16]

4-AryIazo-3,5-diaminoisoxazoIe: Synthesis and Some Chemical Reactions

Abstract Several new isoxazole derivatives were prepared from the newly synthesized 4-arylazo-3,5- diaminoisoxazole