M. S. K. Youssef

SYNTHESIS AND REACTIONS OF SOME THIENOPYRIDINE DERIVATIVES

Abstract Substituted thieno[2,3-b]pyridines (VIII-XII) were prepared by ring closure of the corresponding S-alkylated derivatives (II-VI). Thieno[2,3-b]pyridine-2-carbohydrazide XIII was interacted with some reagents afforded the expected pyridothienopyrirnidines (XIV-XVI). Also, the carboazide XVII undergo Curtius rearrangement giving imidazolothienopyridine (XVIII). The carboxarnide derivatives (X-XII) interacted with CS2 giving pyridothienopyrirnidines (XX-XXII), while interaction with nitrous acid, pyridothienotriazines (XXIII-XXV) were produced.

SOME REACTIONS OF 3-AMINO-2-CARBOETHOXY-4,6-DIMETHYLTHIENO[2,3-b]-PYRIDINE. SYNTHESIS OF SOME NEW THIENOPYRIDOPYRIMIDINES

Abstract Thienopyridine oxazinone (1) has been prepared and explored as a precursor by its reaction with some reagents namely, ammonium acetate, aliphatic amines, aromatic amines, hydrazine hydrate, thiosemicarbazide, and ethyl glycinate to give pyridothienopyrimidines (11-VII). The pyrimidinone compound (11) was converted to the 4-chloro derivative (X) by its reaction with excess POCl3 Interaction of the 4-chlorocompound (X) with some reagents namely, hydrazine hydrate, methyl amine, aniline, sodium thiophenolate, ethyl glycinate, thiosemicarbazide and thiourea, yielded pyridothieno-pyrimidine derivatives (XI-XVII) substituted at 4-position, respectively.

Synthesis of new triphenodithiazine- and indolocarbazolediones of biological interest

Tetrabromo-p-benzoquinone reacted with excess aromatic amines to give 2,5-dirylamino-3,6-dibromo-p-benzoquinones. The latter molecules on heating with sodium sulfide in alcohol in the presence of air gave triphenodithiazinediones. Heating with copper powder in nitrobenzene transformed these compounds into the respective indolocarbazolediones. Comparative antimicrobial and antifungal activities of the studied compounds were determined and discussed.

Recent Trends in the Chemistry of Heterocyclic Sulfides, 1990–2000

This review selectively describes work that generally reflects the recent current state of knowledge about heterocyclic sulfides while emphasizing important developments, methods of synthesis, main reactions, and their biological activities.

Heterocyclic compounds. VIII. Studies on oxazolophenoxazines

5H-Oxazolo[4,5-b]phenoxazine (5) was synthesized by the reaction of 3-amino-2-hydroxyphenoxazine hydrochloride (2) with formamide. A series of styryl-oxazolophenoxazines (9) were prepared by condensation of 2-methyl-5-acetyloxazolo[4,5-b]phenoxazine methiodide (8) with aromatic aldehydes. By contrast, 2-aryl-oxazolophenoxazines (14) were synthesized by reaction of 3-aminophenoxaz-2-one (1) with the appropriate aldehydes in the presence of an acid–base catalyst. The biological activities of some of these compounds were tested.

New Synthesis of Pyrido[2,3-d] and [3,2-d]Oxazines

Abstract N-Hydroxyquinolinimide 1 reacts with each of aromatic amines, hydrazine hydrate and aromatic hydrocarbons to give arylcarbamoyl pyridines 2, pyrrolopyridines 3, pyridopyridazines 4 and pyridooxazinones 5 and 6. The heterocycles 5 and 6 can be transformed to the condensed systems, triazolopyridopyridazines 14 and 15 through series of reactions.

Synthesis and biological activity of some new pyridines, pyrans, and indazoles containing pyrazolone moiety

Cyclocondensation reactions of 3-phenyl-1-(3-methyl-5-oxo-1-phenyl-2-pyrazolin-4-yl) prop-2-en-1-one (2) with active methylene reagents such as ethyl cyanoacetate, malononitrile, ethyl acetoacetate, and acetoacetanilide afforded pyrazolinyl pyridine derivatives (3 and 12), pyrazolinyl pyran derivative (9), and pyrazolinyl cyclohexene derivatives (10 and 11). Reaction of 11 with hydrazines and hydroxyl amine led to the formation of indazole derivatives (13 and 14), and benzisoxazole derivative 15. Also, reaction of 9 with different reagents gave pyrano[2,3-d][1,2,3]triazine (19) and pyrano[2,3-d]pyrimidine derivatives (20 and 21). The anti-inflammatory, analgesic, and antimicrobial activities of these compounds were determined. Compounds 13 and 14 showed good anti-inflammatory activity in comparison with the standard indomethacin, whereas compounds 4, 7, and 12 showed higher analgesic activity than the reference aspirin drug. In addition, compounds 7, 11, and 15 exhibited broad spectrum activities against all bacterial and fungal species tested.Graphical Abstract

SYNTHESIS AND SOME REACTIONS OF 2-MERCAPTO-3,5,7-TRIPHENYLPYRIDO[2,3-d]-PYRIMIDINE-4(3H)-ONE

Abstract 2-Mercapto-3,5,7-triphenylpyrido[2,3-d]pyrimidine-4(3H)-one (II) was synthesized by the interaction of ethyl-2-amino-4,6-diphenylincotinate (I) with phenyl isothiocyanate in pyridine. The reaction of II with different reagents was carried out to give some condensed heterocyclic systems.

Synthesis and antimicrobial activity of some novel 2-thienyl substituted heterocycles

Abstract A series of 2-thienyl substituted derivatives of thiazoles, oxazoles and spiro(indole-azole) were synthesized. The structures of the synthesized compounds were confirmed by IR, NMR and mass spectral data.

Synthesis of new quinoxalinophenazinediones and tetrahydrobenzodipyrrolotetrones of biological interest

The reaction of two equivalents of sodium azide with diarylaminodibromo-p-benzoquinone (I) in DMF for 15–24 h produced quinoxalinophenazinediones together with a byproduct identified as diarylaminodiaminobenzoquinone. On the other hand, the reaction of bromanil with active methylenes, such as diethyl malonate and ethyl acetoacetate, resulted in disubstitution products which, on treatment with primary amines, cyclized into benzodipyrroletetrones. Comparative antifungal and antibacterial studies were made.