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A number of new N-arylaminomethyl-1,3,4-oxadiazole derivatives 2, 3a,b, and 9-12a,b were prepared. Sugar (5-N-arylaminomethyl-1,3,4-oxadiazol-2-yl) hydrazones 4-6a,b were synthesized by the reaction of the hydrazino derivatives 3a,b with the corresponding monosaccharides. The novel acyclo-C-nucleosides 7, 8a,b were prepared by heterocyclization of the sugar hydrazones 4, 5a,b with acetic anhydride. A number of the synthesized compounds were tested for their antiviral activity against herpes simplex virus type-1 (HSV-1) and hepatitis-A virus (HAV, MBBcell culture-adapted strain). The results revealed that the sugar hydrazones 6a,b showed higher antiviral activity compared to the other hydrazones and their acetylated derivatives.

Condensation of aryl hydrazines with ethyl pyruvate gave the respective hydrazones 4-6; Fischer indolization led to substituted-1H-indole-2-carboxylic acid ethyl esters 7-9. The Mannich reaction of these compounds with formaldehyde and morpholine yielded ethyl 3-(morpholinomethyl)-substituted-1H-indole-2-carboxylates 10-12. The 5,7-dichloro-1H-indole-2-carbohydrazide 13 was cyclized with methyl orthoformate in DMF to give 6,8-dichloro[1,2,4]triazino[4,5-a]indol-1(2H)-one 14. Vilsmeier-Haack formylation of 7-9 gave ethyl 3-formyl-substituted-1H-indole-2-carboxylates 15-17 whose 2,2'-((5-chloro-2-(ethoxycarbonyl)-1H-indol-3-yl)methylene)bis-(sulfanediyl) diacetic acid 18 was prepared. The reaction of 15 and 16 with substituted anilines by conventional and microwave methods gave ethyl 3-(N-aryliminomethyl)-5-halo-1H-indole-2-carboxylates 19-29. In a cyclocondensation reaction of 19-25 with thiolactic acid or thioglycolic acid substituted indolylthiazolidinones 30-33 were prepared. Reaction of hydrazine hydrate with 15-17 did not give the respective hydrazones but directly led to the cyclized products substituted-3H-pyridazino[4,5-b]indol-4(5H)-ones 34-36, while a reaction with 2,4-dichlorophenylhydrazine yielded the uncyclized hydrazones. The chlorination of 35 and 36 with POCl3 gave pyridazino[4,5-b]indoles 39 and 40, respectively; reaction of the latter compounds with morpholine gave 4-(substituted-5H-pyridazino[4,5-b]indol-4-yl)morpholine 41 and 42. Mannich reaction of 34 with formaldehyde and N-ethylpiperazine gave 8-chloro-3-((4-ethylpiperazin-1-yl)methyl)-3H-pyridazino[4,5-b]indol-4(5H)-one 43. The microwave assistance of selected reactions has a profound effect on the reaction speed. The structures of the new compounds were confirmed by both analytical and spectral data. Some compounds were subjected to investigations concerning their antimicrobial, tranquilizing, and anticonvulsant activities.

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T he eVect of mixtures of vinyl triphenyl phosphonium bromide containing various anions on E. KHAMISthe corrosion rate of steel in 0•5M H 2 SO 4 has been investigated. T he inhibition mechanism E. S. H. EL-ASHRY has been studied by conducting electrochemical polarisation measurements. T he inhibitor A. K. IBRAHIMacts by covering the cathodic area of the metal surface through adsorption of the phosphorus atom. A synergistic eVect has been observed for KBr, KI, and KSCN with vinyl triphenyl phosphonium bromide. T hus, an improvement in inhibition was obtained by using mixtures compared with that given by individual components. A probable mechanism for this process is suggested. T he degree of surface coverage of iron in acid solution containing 10−5M inhibitor was determined for various concentrations of Br−, I−, and SCN−. T he inhibiting eVectiveness was in the order KI>KSCN>KBr. Protection of 93•8% was given by a mixture of 10−5M inhibitor+10−2M KI. It was observed that the protection eYciency was sharply enhanced in the presence of 10−3M KI with very low concentrations (10−5M-10−4M) of the inhibitor.

Review: 120 refs.

Reaction of ethyl 4-thioxo-3,4-dihydropyrimidine-5-carboxylate derivatives 1a,b and ethyl 4-oxo-3,4-dihydropyrimidine-5-carboxylate 1c with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide in KOH or TEA afforded ethyl 2-aryl-4-(2',3',4',6'-tetra-O-acetyl-beta-D-glucopyranosylthio or/ oxy)-6-methylpyrimidine-5-carboxylate 6a-c. The glucosides 6a and 6b were obtained by the reaction of 1a and 1b with peracetylated glucose3 under MW irradiation. Mercuration of 1a followed by reaction with acetobromoglucose gave the same product 6a. The reaction of 1a-c with peracetylated ribose 4 under MW irradiation gave ethyl 2-aryl-4-(2',3',5'-tri-O-acetyl-beta-D-ribofuranosylthio)-6-methylpyrimidine-5-carboxylate 8a-c. The deprotection of 6a-c and 8a-c in the presence of methanol and TEA/H(2)O afforded the deprotected products 7a-c and 9a-c. The structure were confirmed by using (1)H and (13)CNMR spectra. Selected members of these compounds were screened for antimicrobial activity.

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