99459-27-5Relevant academic research and scientific papers
Photoinduced molecular rearrangements. The photochemistry of 1,2,4-oxadiazoles in the presence of sulphur nucleophiles. Synthesis of 1,2,4-thiadiazoles
Vivona, Nicolo,Buscemi, Silvestre,Asta, Stefano,Caronna, Tullio
, p. 12629 - 12636 (1997)
The photochemistry of some 1,2,4-oxadiazoles in the presence of sulphur nucleophiles has been investigated. Irradiation of the 5-amino-3-phenyl- and 3,5-diphenyl-1,2,4-oxadiazole at λ = 254 nm in methanol in the presence of sodium hydrogen sulphide or thiols gave a photo-induced redox reaction at the ring O-N bond, leading to the corresponding N-substituted benzamidines. By contrast, irradiation of the 5-amino-3-phenyl-1,2,4-oxadiazole in the presence of thioureas or thiocarbamates, essentially gave 3-phenyl-5-substituted 1,2,4-thiadiazoles, which presume an N-S bond formation between the ring-photolytic species and the sulphur nucleophile. In turn, irradiation of the same 5-amino-3-phenyl-1,2,4-oxadiazole in the presence of thioamides again afforded the redox reaction; in addition, amounts of 3-phenyl-5-substituted-1,2,4-thiadiazoles were also formed. Some mechanistic considerations are reported and synthetic methodologies leading to 1,2,4-thiadiazoles are emphasized.
Reactions of halodiazirines with potassium ethyl xanthate
Creary, Xavier
, p. 29 - 32 (2007/10/03)
Aryl halodiazarines are reduced by potassium ethyl xanthate to give benzonitrile as the major product along with significant amounts of a novel heterocyclic product, 3-phenyl-5-ethoxy-1,2,4-thiadiazole. A mechanism involving fragmentation of an N-substituted diazirine is considered.
