6264-40-0Relevant articles and documents
Les magnesiens allyliques comme agents de fonctionnalisation symetrique ou dissymetrique en 2 et 5 du 1,3,4-thiadiazole
Laduranty, Joelle,Miginiac, Leone
, p. 1 - 10 (1994)
Allylic Grignard reagents easily react through addition and elimination, with the two methylthio groups of 2,5-bis(methylthio)-1,3,4-thiadiazole, and with the one methylthio group of 5-methylthio-1,3,4-thiadiazol-2(3H)-thione, to lead to symmetrical or unsymmetrical disubstituted derivatives of 1,3,4-thiadiazole.Key words: Magnesium; Thiadiazole; Addition-elimination reaction
UV-induced transformations of matrix-isolated 1,3,4-thiadiazole-2-thiones
Rostkowska, Hanna,Lapinski, Leszek,Nowak, Maciej J.
experimental part, p. 56 - 66 (2010/07/08)
Monomers of 5-mercapto-1,3,4-thiadiazole-2-thione (bismuthiol) were studied using an experimental matrix-isolation technique as well as by carrying out theoretical quantum chemical calculations. The calculations, performed using the quadratic configuration interaction method with single and double excitations (QCISD)/6-31++G(d,p)//DFT(B3LYP)/ 6-311 ++G(2d,p), predict that the thione-thiol tautomer of bismuthiol should be significantly (by more than 19 kJ mol-1) more stable than other tautomeric forms. Accordingly, only the signatures of the thione-thiol tautomer were observed in the FT-IR spectrum of bismuthiol, recorded directly after deposition of an Ar matrix. UV (l> 320 nm) irradiation induced the conversion of the thione-thiol tautomer into the dithiol form. Analogous investigations were carried out for two related compounds: 5-methyl-1,3,4-thiadiazole-2-thione and 5-methylthio-1,3,4-thiadiazole-2-thione. For these two species, only the thione tautomeric forms were observed after deposition of Ar matrices. These tautomers were predicted (by QCISD calculations) to be more stable (by at least 19kJmol-1) than other tautomeric forms. Upon UV irradiation, the most stable thione forms of these compounds were transformed into the corresponding thiol tautomers. Direct observation of the thione! thiol phototautomeric processes provides a clear proof that intramolecular proton transfer reaction can occur in molecules, such as bismuthiol, in spite of the increased NH...S distance, in comparison to other phototautomerizing species studied so far. All the isomers of the studied compounds (substrates and products of the photoreactions) were identified by comparison of their IR spectra with the spectra calculated at the DFT(B3LYP)/6-311 ++G(2d,p) level of theory for possible isomeric structures. Copyright
S,S'-and S,N-Disubstituted Derivatives of 1,3,4-Thiadiazoledithiones
Katritzky, Alan R.,Wang, Zouquan,Offerman, Rick J.
, p. 139 - 142 (2007/10/02)
Facile synthesis of 2-n-dodecylthio-4-phenylthiomethyl-1,3,4-thiadiazole-5-thione 6, starting from 2,5-dimercaptothiadiazole via 2-n-dodecylthio-1,3,4-thiadiazole-5-thione 2, 2-n-dodecylthio-4-hydroxymethyl-1,3,4-thiadiazole-5-thione 4 and 2-n-dodecylthio-4-chloromethyl-1,3,4-thiadiazole-5-thione 5 is described.
