Study of reaction routes in sulfoination of 2-aminothiazoles with chlorosulfonic acid

Abstract

The sulfonation of 4-substituted 2-aminothiazoles with chlorosulfonic acid under mild conditions afforded primarily 2-amino-5-thiazolesulfonic acids that at heating in sulfuric acid rearranged into the corresponding stable 2-thiazolesulfamoylic acids.

Sulfamic Acid and Its N- and O-Substituted Derivatives

“…Data are also calculated for the less stable thiocarbonyl dioxides, RRC SO 2 . 357 Gas-phase reaction of NH 360 The thionitrosobenzene 80 reacts with oxygen to give a putative N-sulfonylaniline, which undergoes an interesting intramolecular 1,3-dipolar cyclization giving 81 (Scheme 6), and this is the first example of such an addition involving Nsulfonylamines. 361 N-Sulfonylamines have been invoked in several papers involving hydrolysis and aminolysis (Et 2 NH, pyridines, quinuclidines, anilines, and cyclic amines) of sulfamate esters.…”

“…Sulfonation of 4-R-2-aminothiazoles [R = Me, p -BrC 6 H 4 – (or p -Cl or m -NO 2 )] with chlorosulfonic acid gave mainly the C -sulfonated product 2-amino-5-thiazolylsulfonic acids which can then interestingly undergo thermal isomerization into the corresponding 2-thiazolesulfamic acids in Scheme . Many years ago Hurd and Kharasch found that 4-methyl-2-thiazolesulfamic acid undergoes the reverse reaction, isomerizing to 2-amino-4-methyl-5-thiazolesulfonic acid.…”

“…MINDO/3 and AM1 calculations on HNSO 2 and MeNSO 2 have given enthalpies of formation, ionization potentials, dipole moments, and atomic charges. Data are also calculated for the less stable thiocarbonyl dioxides, RRCSO 2 . Gas-phase reaction of NH 2 – and SO 2 F 2 – gives NSO 2 – (85%) and HNSO 2 F – (15%).…”