6269-99-4Relevant articles and documents
Microwave-Assisted Synthesis of 2-Substituted 2-Thiazolines and 5,6-Dihydro-4 H -1,3-thiazines
Bisceglia, Juan A.,Kilimciler, Natalia B.,Mancinelli, Michele,Mollo, María C.,Orelli, Liliana R.
, p. 1666 - 1679 (2020/06/01)
An efficient and general method for the synthesis of 2-substituted thiazolines and 5,6-dihydro-4 H -1,3-thiazines is developed via microwave-assisted ring closure of ω-thioamidoalcohols promoted by ethyl polyphosphate (PPE). The cyclization reaction involves an S N 2-type mechanism and features the advantages of very short reaction times, high yields and a predictable stereochemical outcome. The acyclic precursors are prepared in high overall yields by an improved diacylation-thionation-saponification sequence from commercially available ω-amino alcohols. The whole process is metal-free and operationally simple.
Ammonium nitrate: A biodegradable and efficient catalyst for the direct amidation of esters under solvent-free conditions
Ramesh, Perla,Fadnavis, Nitin W.
supporting information, p. 138 - 140 (2015/02/19)
A simple, metal-free, and environment-friendly procedure is developed for the direct conversion of esters to amides using ammonium nitrate as a catalyst under solvent-free conditions. Aryls, heteroaryls, and aliphatic esters are easily converted to the corresponding amides in excellent isolated yields (85-99%). An enantiopure ester and amine were both shown to react without racemization. The methodology has been successfully applied to preparation of procainamide.
Carboxyl activation of 3-mercapto-5,6-diphenyl-1,2,4-triazine through N-phenylacetyl-5,6-diphenyl-1,2,4-triazine-3-thione
Rajan
, p. 119 - 126 (2019/01/21)
The carboxyl activation ability of 3-mercapto-5,6-diphenyl-1,2,4-triazine has been established by coverting it into N-phenylacetyl-5,6-diphenyl-1,2,4-triazine-3-thione and this was then subjected to aminolysis and esterification with amines and alcohols respectively and selective aminolysis with aminoalcohols-monitoring chemically and confirmed spectrophotometrically by UV-Visible scannings. It could be proved that 3- mercapto-5,6-diphenyl-1,2,4-triazine is an efficient carboxyl activating group which can be successfully applied in solid phase peptide synthesis.