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5-Aryl(or benzyl)-3-(2-bromoethyl)-1,3,4-oxadiazol-2(3H)-ones 3 have been prepared. They were reacted with secondary alkylamines without any change of the heterocycle to give amino derivatives 6, but with primary alkylamines, cyclic transformation occurred to give 1-acylamino-3-alkylimidazolidin-2-ones 7. In the presence of sodium alcoholate, bromo compounds 3 were transformed into 2-aryl(or benzyl)-4-alkoxycarbonyl-5,6-dihydro-4H-1,3,4-oxadiazines 9.

Four 3-(3-benzylidene-2-phenylcarbazoyl)-2(3H)-benzoxazolone derivatives 3 have been synthesized from benzoxazolone derivatives 1 and benzaldehyde N-chloroformylphenylhydrazone 2. By acid hydrolysis, these compounds yielded 3-(2-phenylcarbazoyl)-2(3H)benzoxazolone derivatives 4 which were not isolated and were transformed via an intramolecular reaction into 4-(2-hydroxyphenyl)-1-phenyl-1,2,4-triazolidine-3,5-dione derivatives 5 in a good yield. Attempts to cyclize these compounds by intramolecular elimination of water into tricyclic compounds 6 with various dehydrating agents were unsuccessful.

Some ethyl 5-aryl(or benzyl)-2-oxo-1,3,4-oxadiazole-3(2H)-acetates were prepared and treated with ammonia, primary amines or hydrazine to give 1-amino-2,4-imidazolidinedione or 1,3-diamino-2,4-imidazolidinedione derivatives. The 1,3-bis(benzylideneamino)-,2,4-imidazolidinedione was obtained by reacting ethyl bromoacetate with the 1,5-dibenzylidenecarbonohydrazide sodium salt

The 3,5-disubstituted 1-amino-1,3,5-triazine-2,4,6-triones were synthesized in good yields from aromatic aldehyde or ketone ethoxycarbonylhydrazones by treatment with aryl or methyl isocyanates in boiling triethylamine followed by hydrolysis with hydrochloric acid solution.

L'action des aroylhydrazines sur le ehlorhydrate de benziminoether conduit aux aroyl-liydrazones du benzoate d'ethyle. Ces composes se cyclisent thermiquemenl ou dans l'alcool en presence de carbonate de sodium pour donner les aryl-5 phenyl-2 oxadiazoles-1,3,4 correspondants. L'action de 1′hydrazine conduit aux amino-4 aryl-5 phenyl-3 4H triazoles-1,2,4 et au diphenyl-3,6 tetrazine-1,2,4,5. Enfin, L'iodure de methylmagnesium reagit sur ces hydrazones en formant les aroylhydrazones de L'acetophenone. Les spectres IR, RMN, et UV des nouveaux composes sont etudies. The aroylhydrazones of ethyl benzoate have been prepared in fair yield by the action of aroylhydrazines on ethyl benzimidate hydrochloride. These products give rise, quantitatively, at their melting point, to 5-aryl-2-phenyl-1,3,4-oxadiazoles, and, in the presence of hydrazine hydrate, in boiling 1-propanol to 4-amino-5-aryl-3-phenyl(4H)-1,2,4-triazoles (Yields 50%). The addition of methylmagnesium iodide to these products give aroylhydrazones of acetophenone.

In order to study the ring expansion of N-aminoaziridines into N-amino-5-membered heterocycles, N-(dibenzyloxycarbonylamino)aziridines were synthesized. N, N-Dibenzyloxycarbonylhydrazine was prepared. It was then oxidized with lead tetraacetate to a new diacylaminonitrene. This nitrene was added to various olefins to give the corresponding N-protected aminoaziridines. Cleavage of the protecting groups was realized for one example.

La synthese des arnino-4 aryl-3 triazol-1,2,4 ones-5 a ete realisee par quatre methodes: a partir du carbohydrazide par reactions avec les chlorhydrates d'aryliminoethers, l'orthobenzoate d'ethyle ou le trichlorophenylmethane, et aussi a partir du N-carbethoxyhydrazone du benzoate d'ethyle et de ses derives par reaction avec l'hydrazine. Les mecanismes de ces reactions sont proposes; ils ont en commun la formation d'un intermediaire, la monocarbohydrazone du benzoate d'ethyle. Les spectres ir, uv, rmn de ces heterocycles sont discutes. The synthesis of 4-amino-3-aryl-l,2,4-triazol-5(4H)ones has been accomplished by four methods.

Les spectres de masse des aryl-2 alkyl-4 oxadiazol-1,3,4 ones-5 et de leurs isomeres aryl-2 alcoxy-5 oxadiazoles-1,3,4 ont ete etudies. La fragmentation de ces composes ne semble pas faire intervenir d'isomerisation unimoleculaire d'origine electronique. Pour chaque type d'heterocycle, les transferts d'hydrogene accompagnant la pete de la chaine alcoylee sont principalement induits par l'azote 4. The mass spectra of 2-aryl-4-alkyl-1,3,4-oxadiazole-5-ones and their 2-aryl-5-alkoxy 1,3,4-oxadiazole isomers have been studied. Unimolecular electron impact-induced isomerization does not seem to occur during the fragmentation of these compounds. For each type of heterocycle, the hydrogen transfers, during the cleavage of the alkyl chain, are mainly caused by the nitrogen in position 4.

L'oxydation des aroylhydrazones d'aldehydes aromatiques, par le bioxyde de plomb, dans l'acide aceti-que, constitue une nouvelle methode d'acces, simple et rapide, aux oxadiazoles-1,3,4 correspondants. Dans le dimethylformamide, et en presence du měme oxydant, les carbodihydrazones d'aldehydes aromatiques con-duisent aux aryl-3 arylideneamino-4 triazol-1,2,4 ones-5 correspondantes. Plusieurs mecanismes radicalaires sont proposes. Aromatic aldehyde aroylhydrazones when oxidizen with lead dioxide, in acetic acid, gave quickly the corresponding 1,2,4-oxadiazoles in good yields. Aromatic aldehyde carbodihydrazones on the other hand, gave derivatives of 4-amino-3-aryl-1m,2,4-triazol-5-ones, in dimethylformamide as solvent. To explane these results, some radical mechanisms are proposed.

Some 5-aryl-3-carbazoyl-1,3,4-oxadiazol-2(3H)-one derivatives 6 and 9 have been synthesized in two ways. The expected thermal ring transformation into 2,5-disubstituted 1,3,4-oxadiazoles did not occur but, by acid hydrolysis of 5-aryl-3-[3-benzylidene-2-methyl(or phenyl)carbazoyl]-1,3,4-oxadiazol-2(3H)-ones 6, a new ring transformation took place and the corresponding 4-benzamido-1-methyl(or phenyl)-1,2,4-triazolidine-3,5-dione derivatives 11 were formed. The 4-amino-1-phenyl-1,2,4-triazolidine-3,5-dione (19) has been prepared and its structure was confirmed by some reactions.

Les spectres de masse d'un certain nombre d'amino-4 triazole-1,2,4 ones-5 differemment substituees en position 1 sont rapportes; ils mettent en evidence de nouveaux rearrangements et des migrations d'hydrogene. La comparaison des spectres normaux et des spectres d'energie cinetique obtenus selon la technique simili MIKE a permis de determinerla structure des ions moleculaires et des ions fragments et de decrirela formation de ces derniers. Ces resultats montrent que ľion moleculaire des amino-4 triazolones-5 non substituees en position 1 existe probablement en phase gazeuse sous deux formes tautomeres (N-1-H et OH). The mass spectra of several 4-amino-1,2,4-triazole-5-ones with different groups in position 1 have been recorded and show new skeletal rearrangements and hydrogen migrations. The comparison of the ‘normal’ and mass analysed ion kinetic energy spectra obtained by the ‘simili MIKE’ technique permits the determination of the molecular ion and fragment ion structures and also the mechanism of formation of these ions. These results show that the molecular ion of the N-1 unsubstituted 4-amino-1,2,4-triazole-5-ones exists in the gas phase in two tautomeric forms.

Thirty new 2-substituted-4-amino-5-alkyl or aryl-2,4-dihydro-1,2,4-triazol-3-ones and ten 2-substituted-5-alkyl or aryl-4-(5-nitro-2-furfurylidene)amino-2,4-dihydro-1,2,4-triazol-3-ones were synthesized and characterised by their sharp melting points, elemental analysis, ir and 1H nmr spectra. These new derivatives of 5-nitro-2-furaldehyde were screened for their antibacterial activities. Most of the compounds showed good activity against one test organism, Staphylococcus aureus. For a few compounds, C.M.I. ranged from 4 to 8 μg/ml (higher results than nitrofurantoin).

Une nouvelle synthese generale des dihydro-2,4 triazole-1,2,4 thiones-3 disubstituees en position 4 et 5 est proposee. Ces heterocycles sont obtenus par action d'amines primaires, d'arylhydrazines ou d'aroylhydrazines sur les thiosemicarbazones d'esters. Celles-ci sont preparees par action de chlorhydrates d'iminoethers sur la thiosemicarbazide dans le dimethylformamide. Les thiosemicarbazones se pretent a d'autres reactions avec les acides forts, les anhydrides et chlorures d'acides; par thermolyse, ils donnent des derives de l'amino-2 thiadiazole-1,3,4. Enfin, deux derives du [1,2,4triazolo][3,4-b]thiadiazole-1,3,4 ont ete prepares.

Treatment of various substituted semicarbazones of aromatic aldehydes with sulfur monochloride yields the corresponding substituted 2,4-dihydro-1,2,4-triazol-3-ones. With thiosemicarbazones, the products are derivatives either of the 2-amino-1,3,4 thiadiazole or of the 2,4-dihydro-1,2,4-triazole-3-thione depending on the experimental conditions.

La synthese du chloro-5 phenyl-2 oxadiazole-1,3,4 a ete mise au point. Ce produit est utilisable pour la preparation de derives ou O-alkyles ou O-aryles de l'hydroxy-5 pheenyl-2 oxadiazole-1,3,4. The 5-Chloro-2-Phenyl-1,3,4-oxadiazole has been prepared in fair yield. This product is a convenient starting material for the synthesis of O-alkylated or O-arylated derivatives of the 5-hydroxy-2-phenyl-1,3,4-oxadiazole.

Unstable 5-aryl-2-(3-benzylidene-2-phenylcarbazoyl)-1,2,3,4-tetrazoles 8 have been prepared. By thermal ring transformation, they gave 5-aryl-2-(2-benzylidene-1-phenylhydrazino)-1,3,4-oxadiazoles 9., Hydrazinolysis of 9 afforded 5-aryl-2-(1-phenylhydrazino)-1,3,4-oxadiazoles 10. Elimination of a molecule of benzonitrile from 9 on heating converted them into 2-anilino-5-aryl-1,3,4-oxadiazoles 11.