572-19-0Relevant academic research and scientific papers
Reactions of the activated, rigid, α-diazomethine group of 1,2,5-thiadiazole 1,1-dioxides with nitrogenated nucleophiles. Part III: Aliphatic monoamines and phenylhydrazine
Caram, Jose Alberto,Piro, Oscar Enrique,Castellano, Eduardo Ernesto,Mirifico, Maria Virginia,Vasini, Enrique Julio
, p. 229 - 237 (2007/10/03)
The reactions of n-butylamine (BuNH2), 2-aminoethanol (H 2N(CH2)2OH), diethylamine (Et2NH), and phenylhydrazine (PhN2H3) with 3,4-diphenyl-(1a) and phenanthro[9,10-c]-1,2,5-thiadiazole 1,1-dioxide (1b) were studied by cyclic voltammetry (CV) and 1H- and 13C-NMR in aprotic solvent solution. The course of the reactions depended on the substrate-nucleophile combination: Et2NH added to 1a or 1b, forming the corresponding thiadiazolines in an equilibrium monoaddition reaction. The equilibrium constants were evaluated and compared. With primary amines and PhN 2H3, the nucleophile added to both C=N double bonds of 1a and displaced the sulfamide moiety. In the case of the reaction of la with PhN2H3, the intermediate monoaddition thiadiazoline, 3-(2-phenylhydrazino)-3,4-diphenyl-1,2,5-thiadiazoline 1,1-dioxide, was also isolated. BuNH2 and H2N(CH2)2OH reacted with la to give α-bis-imines, while la with PhN2H 3 gave the α-bis-hydrazone. The configurations of benzil bis(ethanolimine) and benzilosazone were determined by single crystal x-ray diffraction analysis as Z,Z. BuNH2 and PhN2H3 reduced 1b to the corresponding thiadiazoline compound 1bH2. Copyright
The true configuration of the benzilosazone isomers
Mirífico, María V.,Caram, José A.,Vasini, Enrique J.
, p. 6919 - 6922 (2007/10/03)
The 1H NMR-based argument previously used to assign configurations to the three stereoisomers of benzilosazone is briefly reviewed. The configuration of the stable isomer is shown to be Z,Z by single crystal X-ray diffraction analysis, instead of E,E as previously reported. This assignment, together with physical measurements and spectroscopic (NMR and UV) data, allows the establishment of the configuration of all isomers. Computational methods are employed to clarify the relation between the configuration of the isomers and their 1H NMR, thus explaining the origin of the previous erroneous assignment.
Isomerisation of Benzilphenylosazones in the Presence of Acids
Spassov, A. W.,Christova, N. I.
, p. 987 - 992 (2007/10/02)
Isomerisation process of the three stereomeric benzilphenylosazones (Z,Z E,E and Z,E) in a melt of trichloracetic acid and in an ethylacetate solution of conc. sulfuric acid is studied.It is established that the convertion runs irreversibly to the stable E,E-isomer at low acid concentration.The process is reversible at high acid concentration and the equilibrium state depends on this concentration.
