1213-06-5Relevant articles and documents
Syntheses and biological activity of 2-(4'-diethylsulfonamide phenyl)-4-substituted aminomethyl-1,3,4-oxadiazolin-5-thiones
Havaldar, Freddy H.,Khatri, Navinchandra K.
, p. 453 - 456 (2008/02/12)
4-(Chlorosulfonyl) benzoic acid was condensed with diethyl amine to afford 4-(diethylsulfamoyl) benzoic acid 1 which was esterified to obtain methyl ester 2. The condensation of compound 2 with hydrazine hydrate gave hydrazino derivative 3. This intermediate undergoes cyclization with carbon disulphide and potassium hydroxide to yield substituted 1,3,4-oxadiazolin-5-thione 4. Aminomethylation of 4 using different amines furnished 4-substituted aminomethyl-2-(4'-diethylsulphonamide phenyl)-1,3,4-oxadiazolin-5-thiones 5a-e. The structure of the newly synthesized compounds have been established by analytical and spectral data. These compounds have also been screened for their biological activity.
Factors Which Influence the Formation of Oxadiazoles from Anthranilhydrazides and Other Benzoylhydrazines
Peet, Norton P.,Sunder, Shyam
, p. 1807 - 1816 (2007/10/02)
The cyclization of o-aminobenzoylhydrazine (1a) and its 5-methyl derivative 1b with four equivalents and with one equivalent of triethyl orthoacetate (TEOA) was studied. 3-Amino-2-methyl-4(3H)-quinazolinone (2a), 3,4-dihydro-2-methyl-5H-1,3,4-benzotriazepin-5-one (3a) and an imino ether derivative of 2a, N-ethanimidic acid ethyl ester (4a) were obtained from the reaction of 1a with four equivalents of TEOA.These results were compared with those of Merour who isolated 2a and 3a using the same conditions.When 1a was treated with one equivalent of TEOA, 2a, 3a, and a new product, 2-(5-methyl-1,3,4-oxadiazol-2-yl)benzenamine (5a) were produced, and 4a was not.Similar results were obtained with the reactions of 1b with TEOA.Authentic samples of oxadiazoles 5a and b were prepared by alternate routes.Novel acid-catalyzed rearrangements of benzotriazepinones 3a and b, to mixtures of aminoquinazolinones 2a and b and oxadiazoles 5a and b, respectively, were found.The different relative amounts of aminoquinazolinones 2 and oxadiazoles 5 which were produced from these rearrangements allowed us to choose between two potential mechanism for these interesting rearrangements.Treatment of 5-nitrobenzoylhydrazine (37) with four equivalents of TEOA gave three products which were characterized, but did not lead to benzotriazepinone formation.