R. Mahmoud

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.

Synthesis of Novel Indeno[1,2-c]isoquinoline Derivatives

Indeno[1,2-c]isochromene was prepared using the readily obtainable starting materials via the condensation of dimethyl homophthalate with 3,4-dimethoxybenzaldehyde in the presence of sodium methoxide in absolute methanol followed by saponification and cyclization with concentrated sulfuric acid at 0°C. The proclivity of cyclized product for undergoing nucleophilic addition has been tested by reaction with nitrogen nucleophiles. Structural assignments are based on spectroscopic data (infrared, 1H NMR, 13C NMR, and mass spectra) and confirmed by the single-crystal x-ray molecular structure (2 and 3).

Utility of cyano- N -(2-oxo-1,2-dihydroindol-3-ylidene)acetohydrazide in the synthesis of novel heterocycles

Cyano-N-(2-oxo-1,2-dihydroindol-3-ylidene)acetohydrazide was prepared by condensation of isatin with cyanoaceto-hydrazide in refluxing 1,4-dioxane. Subsequent reaction with a variety of electrophilic and nucleophilic reagents afforded novel heterocyclic compounds and spirooxoindoles. The IR, 1H NMR and mass spectra of all the synthesised compounds are discussed.

HETEROANNULATED QUINAZOLINE AND QUINAZOLINONE DERIVATIVES FROM (Z)-2-[1-BENZAMIDO-2-(3,4,5-TRIMETHOXYPHENYL)] VINYL-3,1-BENZOXAZIN-4(3H)-ONE

The title compound 1 was prepared and allowed to react with a series of nitrogen nucleophiles to afford the quinazoline and quinazolinone derivatives 2–12 and tetrazole derivative 13. The IR, 1H NMR, 13C NMR, and mass spectra of all the synthesized compounds were discussed.

Reactions of 3-[3-Chlorophenyl]-1-[4-(3,4-Methylenedioxybenzylidine) a Minophenyl]Prop-2-Enone with Some Nucleophiles

Abstract The action of 2-mercaptoacetic acid, thiosemicarbazide and hydrazine hydrate on the titled compound 1 is studied. On the other hand, the behaviour of the titled compound towards thiourea, ethyl acetoacetate and malononitrile under Michaels conditions is reported. The structure of the new heterocycles 2 - 8 is discussed in the light of IR and 1HNMR spectra.

Design, Synthesis, and Antimicrobial Evaluation of Novel Thienopyrimidines and Triazolothienopyrimidines

Abstract 2-Cyanoacetohydrazide and 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene derivatives were exploited as starting materials for the syntheses of novel thienopyrimidines and triazolothienopyrimidines. The proclivity of these compounds toward one-carbon donor reagents such as carbon disulfide, phenyl isothiocyanate, and aromatic aldehydes was investigated. The structures of all synthesized compounds were ascertained by spectral and analytical data. The antimicrobial activity of the target synthesized compounds was tested against various microorganisms. GRAPHICAL ABSTRACT

Synthesis and Reactions of Novel 2,5-Disubstituted 1,3,4-Thiadiazoles

Abstract The desired 1,3,4-thiadiazole compounds bearing different substituents were obtained by the cyclization of the corresponding thiosemicarbazide followed by the reaction with electrophilic reagents, such as aromatic aldehydes, isatin, phenyl isothiocyanate, and carbon disulfide. The newly synthesized 2,5-disubstituted 1,3,4-thiadiazoles were obtained in good yields and their structures were elucidated by spectral data and elemental analysis. [Supplementary materials are available for this article. Go to the publishers online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] GRAPHICAL ABSTRACT

Novel isocoumarin and isoquinoline derivatives

A number of novel isoquinoline-1,3-dione derivatives have been synthesised using the readily obtainable anhydride formed from the Stobbe-type condensation of diethyl homophthalate with p-anisaldehyde. Primary amines form amides at the C-1 carbonyl group; recyclisation gives 4-(4-methoxybenzylidene)isoquinoline-1,3-diones.

New 2,3-disubstituted quinazolin-4(3H)-ones from 2-undecyl-3,1-benz-oxazin-4-one

2-undecyl-4H-3,1-benzoxazin-4-one (2) was prepared and reacted with primary and secondary amines affording compounds 3–7, while with hydrazine hydrate it gave the quinazolinone derivative 8. The reaction of 8 with 3,4,5-trimethoxybenzaldehyde followed by thioglycollic acid yielded 9 and 10, respectively. Acylation of 8 using cinnamoyl chloride gave 11. Furthermore, treatment of 2 with hydrazine derivatives provided 12 and 13. Fusion of 2 with ammonium acetate gave the quinazolinone derivative 14 which upon treatment with ethyl chloroacetate yielded the ester 15. The hydrazide 17 was obtained from hydrazinolysis of the ester 15.

Studies on chromones and xanthone derivatives

Abstract 2-Methyl-6-phenyl chromone la and a variety of its derivatives were synthesized. The reactivity of In and other chromones with aromatic aldehydes, hydrazine hydrate, hydrazine derivatives. Hydroxylamine hydrochloride, different primary amines and Grignard reagents was investigated. The I.R. and H1NMR spectra of the products are discussed.