O. S. Moustafa

Synthesis and Antimicrobial Activity of Some New Cyanopyridines, Isoxazoles, Pyrazoles, and Pyrimidines Bearing Sulfonamide Moiety

Reaction of p-aminoacetophenone 1 with p -substituted benzenesulfonyl chloride 2a , b in pyridine afforded p-acetyl derivatives 3a , b , which was then condensed with araldehydes to yield the corresponding chalcones 4a-f . On condensation of latter chalcones with malononitrile afford cyanopyridines 5a-f , the reaction of chalcones 4a-f with hyroxylamine hydrochloride furnished isoxazoles 6a-f , while condensation of chalcones with hyrazine hydrate afforded pyrazoline derivatives 7 , 8 . Urea or thiourea was reacted with chalcone 4b to yield pyrimidine derivatives 9 , 10 . The reaction of sulphonylchlorides 2a , b with P -aminobenzophenone yield p-[(benzensulphonyl)amido]benzophenone 11a , b , which was then condensed with hydrazine hydrate to give the corresponding hydazone derivatives 12a , b .

Synthesis and biological study of some new naphtho[2,1-b]furan and related heterocyclic systems

In the reaction of 1-cyano-2-naphthol (4) or its sodium salt with different alkylating agent, the O-alkylated derivatives (5a–d) were produced which underwent ring closure reactions using sodium ethoxide solution to give aminonaphtho [2,1-b]furan derivatives (6a–d). Ethyl 3-aminonaphtho[2,1-b]furan-2-carboxylate (8) was reacted with formamide to afford naphtho[1′,2′: 4,5]furo[3,2-d]pyrimidine (11) derivatives. The produced pyrimidino compound underwent various reactions to synthesise other heterocyclic compounds.

Synthesis and Antimicrobial Activity of some New Heterocycles Based on 3-Methyl-1-Phenyl-5-Benzene Sulfonamido Pyrazole

Treatment of 3-methyl 1-phenyl-5-amino pyrazole 1 with 4-acetyl benzene sulfonyl chloride in pyridine gave the sulfonamide 2 . Condensation of 2 with aromatic aldehydes, semicarbazide, and thiosemicarbazide furnished the f , g -unsaturated ketones 3a-c , the semicarbazone 4a and the thiosemicarbazone 4b respectively. Reaction of 3a-c with hydrazine hydrate, phenyl hydrazine, hydroxylamine, thiourea afforded the pyrazoles 5a-f , isoxazoles 6a-c , and pyrimidinethiones 7a-c . Reaction of 3a-c with malononitrile in ethanol containing piperidine provided the pyran derivatives 8a-c , while, when the reaction was carried out in boiling acetic acid in presence of ammonium acetate, the pyridine derivatives 9a-c were formed. When 4a reacted with thionyl chloride and with selenium dioxide, 1,2,3-thiadiazole and 1,2,3-selenadiazole 10 , 11 were formed respectively. Allowing 4b to react with f -halocarbonyl compounds such as phenacyl bromide, chloroacetone, 2-bromomethyl propionate, chloroacetic acid, and bromo diethylmalonate afforded the thiazolines 12a , b and thiazolidinones 13a-c respectively.

CHEMISTRY AND CYCLIZATION REACTIONS OF 2-METHYLPYRIMIDO THIENOQUINOXALINE DERIVATIVES, PART III

Abstract Treatment of 2-methyl-pyrimido[4′,5′:4,5]thieno[2,3-b]-quinoxalin-4-one (2) with a mixture of phosphorous oxychloride phosphorous pentachloride affords 4-chloroderivatives (3). Treatment of 2 with phosphorous pentasulphide give the 4-thione derivative (4) which reacts with methyl iodide to yield the 4-methylthioderivative (6). Treatment of 3 with different nucleophiles, namely; hydrazinehydrate, aniline and dimethylamine, produce, 4-hydrazino-(5); 4-anilino-(7) and 4-dimethylamino-(8) derivatives, respectively. However, treatment of 3 with ethylglycinate gives 5-methyl imidazo[1″,2″: 1′,6′]pyrimido-[4′,5′:4,5]thieno[2,3-b]quinoxaline-3-one (9). 4-Hydrazino-2-methylpyrimido[4′,5′:4,5]thieno[2,3-b]quinoxaline (5) was condensed with p-substituted benzaldehydes to produce the corresponding hydrazones (10a–c). Treatment of 5 with acetic anhydride affords the hydrazinotriacetate compound (11), while with phthalic anhydride affords the corresponding 2-(pyrimido-thienoquinoxalin-4-yl)-dihydro-1,4-phthala...

“Bridgehead Nitrogen Heterocycles: Synthesis and Reactions of S-Triazolothiadiazinyl and S-Triazolothiadiazo-Lylquinoxalines”

Abstract The reaction of 3(4-amino-5-mercapto-1,2,4-triazol-3′-yl)quinoxalin-2(1H)-one 4 with phenacyl bromide, 2,3-dichloroquinoxaline, benzoine, chloroacetic acid, and α-chloroacetonitrile to give triazolothiadiazino derivatives 5–10. Reaction of 4 with phenyl isothiocyanate, aromatic aldehydes, formic acid, aromatic carboxylic acid, benzoyl chloride, and carbon disulphide gave triazolothiadiazino derivatives 11–17.

SYNTHESIS AND REACTIONS OF NEW TRIAZINO THIADIAZINO AND PYRIMIDO THIENO[2,3-b]-QUINOXALINE

Abstract 3-Amino-2-carbamoylthieno[2,3-b]quinoxaline 3 was synthesized and allowed to react with chloroacetyl chloride to give N-chloroacetyl derivative 4. Cyclization of 4 into the title compund 5 was achieved in boiling acetic anhydride. Reactions of 5 with morpholine and diethylamine afforded pyrimidinones 6 and 7. Reaction of 3 with sulfuryl chloride, thionyl chloride and nitrous acid gave thiadiazine derviatives 8 and 9 and triazinothienoquinoxaline 11. Thionation and chlorination of 11 by P2S5 and/or POCl3 gave thioxotriazino and chlorotriazinothiencquinoxalines 12 and 13, respectively. Treatment of either 12 or 13 with hydrazine hydrate afford the hydrazinotriazinoquinoxaline 14 which was utilized as precursor for producing other new triazinothiencquinoxalines 15–17.

CHEMISTRY AND CYCLIZATION REACTIONS OF 2-MERCAPTO-3-PHENYL PYRIMIDO THIENO[2,3-b]QUINOXALINONE DERIVATIVES

Abstract Reaction of 2-mercapto-3-phenyl pyrimido[4′,5′:4,5]thieno[2,3,-b]quinoxalin-4-one(1) with hydra-zine hydrate gives 2-hydrazino derivative (2) which undergoes ring closure reactions with formic acid, acetic anhydride, and benzoyl chloride to produce the S-triazolo derivatives(3–5). While treatment with nitrous acid gives the tetrazolo derivative (6). Reaction of (2) with acetylacetone, phthalic anhydride, and/or aromatic aldehydes affords, N-pyrazolyl-N-phthalazino- and N-arylidene derivatives (7–9) respectively. Compound (1) reacts with alkyl halides in basic medium to give the corresponding thioethers (10). Compound (1) reacts with diethyl bromomalonate to yield (11) which is transformed into (12a.b) under the influence of hydrazine or phenylhydrazine. Treatment of (1) with ethyl chloroacetate yields the thioester (13). Reaction of (1) with chloroacetamide or (13) with ammonia gave the same product. Hydrazinolysis of the thioester (13) gave the corresponding carbohydrazide (15) which reacts with...

Synthesis of new triazoloquinoxalines, pyrroloquinoxalines, and pyrimidopyrroloquinoxalines

SummaryWhen 2-hydroxyquinoxaline-3-carboxamide (1) was reacted with POCl3 inDMF, 2-chloro-3-dimethylaminomethylenecarboxamide (2) was obtained. The chloro compound2 was reacted with thiourea and hydrazine hydrate to give the corresponding mercapto and hydrazino derivatives3 and8, respectively. On the other hand, 2-chloroquinoxaline-3-carbonitrile (13) reacted with ethyl glycinate to the glycinate derivative14 which was cyclized to pyrroloquinoxaline15 by heating with sodium ethoxide. Pyrimidopyrroloquinoxaline derivatives16 and17 were obtainedvia the reaction of15 with formamide and phenyl isothiocyanate, respectively.ZusammenfassungWenn man 2-Hydroxychinoxalin-3-carboxamid (1) mit POCl3 inDMF reagieren läßt, erhält man 2-Chlor-3-dimethylaminomethylencarboxamid (2). Die Chlorverbindung2 wurde mit Thioharnstoff und Hydrazinhydrat zu den entsprechenden Mercapto- und Hydrazinderivaten3 und8 umgesetzt. Aus 2-Chlorchinoxalin-3-carbonsäurenitril (13) und Ethylglycinat erhält man14, das durch Erhitzen mit Natriumethylat zum Pyrrolochinoxalin15 cyclisiert wurde. Die Pyrimidopyrrolochinoxalinderivate16 und17 wurden durch Reaktion von15 mit Formamid bzw. Phenylisothiocyanat erhalten.

CHEMISTRY AND CYCLIZATION REACTIONS OF THIENOQUINOXALINE DERIVATIVES: PART I

Abstract Reaction of 2(1H)quinoxalinethione-3-carbonitrile 1 with alkyl or aralkyl halides, chloroacetic acid, ethyl chloroacetate, or N-phenylchloroacetamide in ethanolic sodium acetate solution gives the corresponding 3-thioethers of 1. Treatment of 3 with acetic anhydride gives the dimesoionic thiazolo[3′,4′-c]-2-cyanoquinoxaline, 4. Treatment of 6 or 10 with ethanolic sodium ethoxide solution gives the cyclization products, ethyl-3-aminothieno[2,3-b]quinoxaline-2-carboxylate 7 or 3-phenylcarboxamide 11 substituents respectively. Treatment of 11 with carbon disulfide/ethanolic potassium hydroxide soution gives 3-phenylpyromido[4′,5′:4,5]thieno[2,3-b]quinoxaline-4-one-2-thione 12 which is also produced by treatment of 7 with phenyl isothiocyanate in dry pyridine. Compound 11 cyclizes on treatment with benzoyl chloride, acetic anhydride, phenyl isothiocyanate, ethyl chloroformate and/or nitrous acid, to produce the corresponding pyrimidothienoquinoxalines 14–17 and [1,2,3] triazinothienoquinoxaline 18 de...

Synthesis and reactions of some new pyrrolylthieno[2,3-D]quinoxaline and pyrrolopyrazinothienoquinoxalines

The synthesis of 3-pyrrolyl-2-substituted thieno[2,3-b]quinoxalines from the precursor 3-amino derivatives are described. Synthesized compounds were subjected to reactions with other reagents to synthe-size polyfused heterocyclic incorporated thienoquinoxaline moiety. Some of the synthesized compounds were screened for their antibacterial and antifungal activities.