Mohammad E. Azab

UTILITY OF 1-(2,4-DIMETHOXYPHENYL)-3-ARYL-PROP-2-ENE-1-ONES AS RING TRANSFORMER IN PREPARING HETEROCYCLIC COMPOUNDS AND THEIR POTENTIAL BIOLOGICAL ACTIVITIES

As an effort to synthesize new heterocyclic compounds, which would be expected to have a pharmacological and biological activities, we report here the reactivity of 1-(2,4-dimethoxyphenyl)-3-aryl-2-propen-1-ones (Ia&b), as Michael acceptors under different conditions, towards different Michael donors namely, pyrazolin-5-one, 2-cyanomethylthiazolidin-4-one, thiobarbituric acid, cyclohexanone, and ethyl cyanoacetate affording the adducts bispyrazolo[5,4-b]-4H-pyranes III, 5-oxopyrazolin-4-yl-propan-1-ones IV, 2-(4-oxothiazolidine-2-yl)-5-oxopentano-carbonitrile XI, 4-oxo-4H-pyranol[2,3-d]tetrahydropyrimidin-2-thiones XVI, cyclohexano[b]-4H-pyran XVII, ethyl-5-oxo-pentanoate XVIII, and 1-aroyl-2-arylcyclopropanes XIX respectively. Fusion of XI with excess ammonium acetate yielded 2-aminopyridine derivative XII and 2-aminotetrahydropyridine derivative XIII. Diazotization of XII by treatment with HNO2 at 0°C produced the diazonium chloride derivative XIV which underwent coupling reaction with phenolic compounds to yield the azo-disperse dyes XV. Alkaline hydrolysis of XVIII afforded the corresponding acid XX which reacted with hydrazines by fusion to yield the diazapinone derivatives XXI. The structures of the products obtained were confirmed by elemental analysis, infrared, 1H-NMR, 13C-NMR, and mass spectra. The biological activity for some synthesized products are screened.

Utility of the Enaminonitrile Moiety in the Synthesis of Some Biologically Active Thienopyrimidine Derivatives

Because of its broad spectrum of biological activities, a novel series of thienopyrimidines and fused thienopyrimidines have been synthesized by reacting the enaminonitrile 1 with different reagents. Thus, reaction of 1 with urea, thiourea, formic acid and/or formamide afforded pyrimidine derivatives 2, 3, 4, and 5, respectively. Compound 4 reacted with POCl3/PCl5 giving the chloro-derivative 7 which upon treatment with thiourea, hydrazine, piperidine and/or thiols, produced 4-thio, 4-hydrazino, 4-piperidino- and 4-S-substituted pyrimidine derivatives 8–11, respectively. Treatment of 9 with ethyl chloroformate, sodium nitrite/hydrochloric acid, benzoyl chloride, acetic and/or formic acid, benzaldehyde/piperidine and CS2/pyridine provided the carbazate 13, tetrazole 14, triazoles 15, and 16a, b, Schiffs base 17 and triazole 18, respectively. Some of the new synthesized compounds were screened for antibacterial activity. The structures of these compounds were confirmed by FT-IR, 1H NMR and correct elemental analysis.

Synthesis, Antimicrobial and Anti-inflammatory Activity of Some New Benzoxazinone and Quinazolinone Candidates

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.

Synthesis and Antibacterial Activity of Some New 4(3H)Quinazolin-4-one Derivatives

2-Phenylamino-6,8-dibromo-4H-3,1-benzoxazinone has been reacted with nitrogen nucleophiles, such as hydrazine hydrate, amines, and formamide, yielding 4(3H)quinazolinone derivatives; and with sulfur nucleophiles producing the corresponding thioesters. The behavior of aminoquinazolinone and 4(3H)quinazolinone towards some carbon electrophiles under different conditions has been studied.

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

3,1-benzoxazin-4H-one derivative was reacted with Grignard reagents, primary and secondary amines, glycine, hydrazine hydrate, azines, and Schiffs 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.

The Utility of 2-(5,6,7,8-Tetrahydrobenzo[b]thieno-[2,3-d]pyrimidin-4-yloxy) Acethydrazide in Heterocyclic Synthesis

Because of being a versatile synthon, the title compound 2 was utilized to construct different heterocyclic systems including pyrazol-4-carbonitrile 3, pyrazolone 4, triazole-5(4H)-thione 7, aminotriazole 9, oxadiazoles 10 and 12, thiazolidine 13, and oxatriazole 14. All new synthesized compounds were structurally confirmed by elemental analyses and spectroscopic data.

Pyrimidinthiones (Part I): Utility of 2-Thioxopyrimidin-6-(1H)ones as Ring Transformer in the Synthesis of Fused Bi- and Tri-Cyclic Heterocyclic Compounds and Their Potential Biological Activities

The pyrimidinethiones have wide biological and pharmaceutical activities, that have attracted considerable interest in recent years especially as antiviral inhibiting production of hepatitis B virus (HBV), and in vitro insulin-mimetic. Activity of the complexes of pyrimidinone derivatives evaluated from 50% inhibitory concentration promoted us to study the transformation of the 2-thioxopyrimidin-6(1H) ones to fused bi- and tri-cyclic heterocyclic compounds having the pyrimidine moieties and screening their biological activity. The reactivity of 2-mercapto-4-aryl-5-cyanopyrimidin-6(1H)ones (1) towards alkylation by different mono and bifunctional halo-organic compounds has been investigated to give S-monoalkylated products 2, 7 and 9; S- and N-dialkylated products 3, 13 and 14. Treatment of 1 and/or 2 with hydrazine hydrate as a nitrogen nucleophile have been investigated to give 4, treatment of 4 with CS2 and sodium nitrite in the presence of acetic acid (0°C) produced 1,2,4-triazolopyrimidin-5(1H)one derivatives (5)and tetrazolo[1,5-a]pyrimidin-5(1H)ones (6), respectively. Also cyclization of 7 and 9 gave [1,3]thiazolo[3,2-a]pyrimidin-5(1H)one and [1,3]thiazolo[3,2-a]pyrimidin-3,5-dione derivatives 8 and 10 respectively, treatment of 10 with aromatic aldehyde produces 11 which reacted with guanidine HCl to give pyrimido[4,5-d]thiazolo[3,2-a]pyrimidin-6(1H)one derivative 12. Reaction of 14 with o-phenylenediamine was investigated and gave [1,4]quinoxalino[2,3-b][1,3]thiazolo[3,2-a]pyrimidin-9(1H)one derivative 15.

Follicle-stimulating hormone (FSH) activities of some synthesized isoxazole and pyrazoline derivatives

A novel series of arylidiene, isoxazole, pyrazolines, and their derivatives 2-8 were synthesized by using estrone (3-hydroxyestran-17-one, 1) as starting material. Some of the synthesized compounds were screened as follicle-stimulating hormone (FSH) agents. The synthesized compounds were illustrated by elemental analysis and spectroscopic evidences.