155189-69-8Relevant articles and documents
Base-promoted ring expansion of 3-aminopyrimidine-2-thiones into 1,2,4-triazepine-3-thiones
Fesenko, Anastasia A.,Shutalev, Anatoly D.
supporting information, p. 2560 - 2573 (2016/04/26)
A base-promoted ring expansion of 3-amino-4-hydroxyhexahydropyrimidine-2-thiones into 2,4,5,6-tetrahydro-3H-1,2,4-triazepine-3-thiones has been developed. Experimental data and DFT calculations showed that the reaction proceeded through fast formation of intermediate acyclic isomers of pyrimidines followed by their slow cyclization into triazepines. The starting hydroxypyrimidines were prepared by reaction of α,β-unsaturated ketones or β-alkoxy ketones with HNCS followed by treatment of the obtained β-isothiocyanato ketones with hydrazine. Triazepine-3-thiones were transformed into their 3-oxo analogs by oxidation with H2O2 under basic conditions.
Direct organocatalytic hydroalkoxylation of α,β-unsaturated ketones
Ramachary, Dhevalapally B.,Mondal, Rumpa
, p. 7689 - 7693 (2007/10/03)
The direct addition of a variety of alcohols to in situ activated olefins was observed in the presence of mild bifunctional amine/acid catalysts. Unlike existing methods, the reactions proceed at room temperature and in the absence of transition metals. The use of simple commercially available catalysts, amines and acids makes this an attractive method for the preparation of β-alkoxy ketones, which are prevalent targets and intermediates in organic synthesis.
