Ahmed I. Khodair

5-substituted-2-thiohydantoin analogs as a novel class of antitumor agents.

Certain series of 2-thiohydantoin derivatives, carrying various substituents at position 5 such as 5-bromo-2-thienylmethylene, 5-(2-carboxyphenylthio)-2-thienylmethylene and 2-methylene-4H-thieno[2,3-b][1]benzothiopyran-4-one, were evaluated for their antitumor activity. Compound 5-(5- bromo-2-thienylmethylene)-3-morpholinomethyl-2-(2,3,4,6- tetra-O-acetyl--D-glucopyranosylthio)hydantoin proved to possess a broad spectrum antitumor activity against a wide range of different human cell lines of nine tumor subpanels causing both cytostatic and cytotoxic effects, resulting in full panel median growth inhibition (GI50) and total growth inhibition (TGI), with a median lethal concentration (LC50) at 15.1, 41.7 and 83.2βM, respectively. On the other hand, compound 5-(5-bromo-2-thienylmethylene)-2-thiohydantoin and compound 5-(5-bromo-2-thienylmethylene)-3-phenyl-2- (2,3,4,6-tetra-O-acetyl-bb-D-galactopyranosyl-thio)hydantoin showed potential selectivity against leukemia cell lines. Further derivatization of these compounds, deduced from the obtained tentative structure activity relationships, may lead to more potent agents

A new approach to the synthesis of substituted 4-imidazolidinones as potential antiviral and antitumor agents

Abstract 5-((Z)-Arylidene)-2-((2-(E)-benzylidene)hydrazone)-4-imidazolidinones 7a-d and 5-((Z)-arylidene)-2-((2-(E)-polyhydroxyalkylidene)hydrazono)-4-imidazolidinones 11a-d to 15a-d were prepared from the reaction of 5-((Z)-arylidene)-2-methylmercaptohydantoins 3a-d with 2-(E)-benzylidene hydrazone 6 or 2-(E)-monosaccharides hydrazones 9a-e, which in turn were prepared by condensation of benzaldehyde or appropriate monosaccharides 8a-e with hydrazine hydrate. AM1 semi-empirical calculations reveal that the azine system is favoured with a trans geometry and planar conformation for CN-NC. All the new compounds were tested for their potential antiviral and antitumor activities.

SYNTHESIS, CONFORMATIONAL ANALYSIS AND ANTITUMOR TESTING OF 5-(Z)-ARYLIDENE-4-IMIDAZOLIDINONE DERIVATIVES

Abstract A series of 5-(Z)-arylidene-2-amino-4-imidazolidinones 16–34, 5-(Z)-arylidene-2-(2-carboxyphenylamino)-4-imidazolidinones 35–41, 5-(Z)-arylidene-3-aminomethyl-2-thioxo-4-imidazolidinones 42–55 and 5-(Z)-arylidene-3-aminomethyl-2-methylmercapto-4-imidazolidinones 56–67 have been synthesized via two different routes. Conformational analysis and antitumor activities have been studied. The antitumor activity of these compounds showed broad spectrum of activity against a wide range of different human cell lines of nine tumor subpanels causing both cytostatic and cytotoxic potency.

GLYCOSYLATION OF 2-THIOURACIL DERIVATIVES. A SYNTHETIC APPROACH TO 3-GLYCOSYL-2,4-DIOXYPYRIMIDINES

Abstract Reaction of 6-aryl-5-cyano-2-thiouracils 2a-d with glycosyl halides 4a,b under alkaline conditions gave the respective bisglycosylated derivatives 5a-h. However, their deacetylation with ammonia in methanol caused a cleavage of the S-glycosyl residue and gave the N-3 glycosylated analogues 6a-h.

SYNTHESIS, REACTIONS AND CONFORMATIONAL ANALYSIS OF 5-ARYLIDENE-2-THIOHYDANTOINS AS POTENTIAL ANTIVIRAL AGENTS

Abstract (Z)-5-Arylidene-1-(4-methylphenylsulfonyl)-2-thiohydantoins 5a,b were synthesized from the direct condensation of the aromatic aldehydes 4a,b with 1-(4-methylphenylsulfonyl)-2-thiohydantoins 3a,b. Compounds 5a,b were coupled with 2′-deoxy-3′,5′-di(4-methyl-benzoyl)-α-D-erythro-pentofuranosyl chloride 6 under alkaline conditions to afford N3-protected nucleosides 7a,b. Reaction of 5a,b with chloromethyl methyl sulfide and/or 2-bromoacetaldehyde diethyl acetal in alkaline medium afforded N3-alkyl derivatives 8a-c. Reaction of 5a with 1,2-dichloroethane in alkaline conditions afforded bis-thiohydantoinylethane 9a,b. Compounds 5a,b were condensed with formaldehyde and secondary amines to afford 3-aminomethyl-2-thiohydantoins derivatives 10a-d. On the other hand, reaction of unsubstituted 2-thiohydantoins derivatives 11b,c with chloromethyl methyl sulfide afforded the mono- and bis-methylthio derivatives 12a,b and 13a,b, respectively. Reaction of 11b,c with secondary amines and formaldehyde gave 3-aminomethyl-2-thiohydantoins 14a-e. Reaction of 11a-c with bromoacetaldehyde diethyl acetal yielded the S-alkyl derivatives 15a-c which can be hydrolysed with ethanolic hydrochloric acid to afford 5-arylidenehydantoins 16a-c. The compounds do not display any antiviral activity.

A new approach to the synthesis of benzothiazole, benzoxazole, and pyridine nucleosides as potential antitumor agents.

Abstract A modified nitrogen and sulfur glycosylation reaction involving benzothiazole benzoxazole and pyridine nucleoside bases with furanose and pyranose sugars are described. Conformational analysis has been studied by homo- and heteronuclear two-dimensional NMR methods (2D DFQ-COSY, HMQC and HMBC). The N and S sites of glycosylation were determined from the 1H, 13C heteronuclear multiple-quantum coherence (HMQC) experiments. All the deprotected nucleosides were tested for their potential antitumor activity.

Synthesis of 2-thiohydantoins and their S-glucosylated derivatives as potential antiviral and antitumor agents.

A series of 3-alkyl-5-((Z))-arylidene-2-thiohydantoins 4a-l were synthesized from the direct condensation of the aromatic aldehydes with 3-alkyl-2-thiohydantoins 3a-c, which in turn were prepared from the reaction of glycine (1) and alkyl isothiocyanates 2a-c. The alkylation of 4a-l with methylthioethyl chloride gave 5-((Z))-arylidene-3-alkyl-S-(2-methylthioethyl)-2-thiohydantoins 5a-e. S-Glucosylation took place on the reaction of 4a-l with 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide under anhydrous alkaline conditions. These structures have been confirmed from a model study of the coupling of 4a with methylthioethyl chloride and α-D-glucose pentaacetate, respectively under Lewis acid conditions.

A CONVENIENT SYNTHESIS OF GLYCOSYLATED HYDANTOINS AS POTENTIAL ANTIVIRAL AGENTS

Abstract Reaction of 5-arylidene-2-thiohydantoins 3a-d with glycosyl halides 4a,b under alkaline conditions gave the respective bisglycosylated derivatives 5a-h. Deacetylation with ammonia in methanol caused a change of the S-glycosyl residue and gave the N-3 glycosylated analogues 7a-h. S-Glycosylation also occured when N-3 substituted hydantoins 9a-h were reacted.

Synthesis of Hydantoin Nucleosides with Naphthylmethylene Substituents in the 5-Position

Abstract (Z)-5-(Naphthylmethylene)-2-thiohydantoin derivatives (3a,b,12a-d) were prepared directly fiom condensations of 2-thiohydantoin derivatives (1,l la,b) with naphthaldehydes. Bisglycosylation took place on reaction of (Z)-5-(naphthylmethylene)- 2-thiohydantoin derivatives (3a,b) with glycosyl halides (4a,b) under alkaline conditions. The bisglycosilated hydantoins produced N3 glycosylated hydantoins on treatment with ammonia in methanol. (Z)-5-(2-Naphthylmethylene)-2-(benzylidene E-hydrazono)hydantoin (9a) and (Z)-5-(2-naphthylmethylene)-2-(polyhydroxyalkylidene E-hydrazono)hydantoins (9b,c) were prepared fiom the reaction of (Z)-5-(2-naphthyylmethylene)-2- methylmercaptohydantoin (7) with benzylidene E-hydrazone (8a) and monosaccharide E-hydrazones (8b,c). S-Glycosylation also took place when N3 substituted hydantoins were reacted. The hydantoin nucleosides were tested for their potential activity against HTV and HSV.

SYNTHESIS OF 15H-ISOQUINO[2′,3′:3,4]IMIDAZO[2,1-B]QUINAZOLINE-7,13,15-TRIONES AND 14H-ISOQUINO[2′,3′:3,4]IMIDAZO[2,1-B]BENZO[G]QUINAZOLINE-8,14,16-TRIONE AS NEW POLYCYCLIC FUSED-RING SYSTEMS

3-Thioxo-2H-imidazo[1,5-b]isoquinoline-1,5-dione (3) and 2-sub-stituted 3-thioxo-2H-imidazo[1,5-b]isoquinoline-1,5-diones (4a–l) were prepared from the reaction of 2-thiohydantoin (2) and 3-substituted 2-thiohydantoin (5a–l) with 2-formyl benzoic acid (1). Alkylation of 3 under an anhydrous basic conditions afforded 4a–i. The alkylation of 3 in aqueous basic solution afforded 3-(alkylmercapto)imidazo[1,5-b]isoquinoline-1,5-diones (7a,b). Reactions of the aromatic amino acids 9a,b and 12 with 7a afforded 2-(2H-1,5 dioxoimidazo[1,5-b]isoquinazolin-3-ylideneamino)benzoic acids (10a, b) and 3-(2H-1,5-dioxoimidazo[1,5-b]isoquinazolin-3-ylideneamino)2-naphthalenecarboxylic acid (13), which were then cyclyzed by heating in acetic anhydride to afford 15H-isoquino[2′,3′ :3,4] imidazo[2,1-b]quinazoline-7,13,15-triones (11a,b) and 14H-isoquino[2′,3′:3,4]imidazo[2,1-b]benzo[g]quinazoline-8,14,16-trione (14). Some of the new compounds were tested for their antitumor activities.