Alo, Babajide I. published the artcileDirected metalation of pyridinesulfonamides. Synthesis of pyridine-fused isothiazoles and 1,2-oxathioles, Application of Pyridine-3-sulfonic acid, the publication is Journal of Heterocyclic Chemistry (1992), 29(1), 61-4, database is CAplus.
4-Lithio-N–tert-butylpyridine-3-sulfonamide reacted with Ph2CO or CO2 to give the corresponding intermediates, which on appropriate treatment gave the addition product I (from Ph2CO reaction product) or isothiazolo[5,4-c]pyridin-3-one 1,1-dioxides II (R = H, Me3C) (from CO2 reaction product). Metalation of 2- and 4-[N,N-(dialkylamino)sulfonyl]pyridines with LiN(CHMe2)2 gave anions which reacted with Ph2CO to give carbinols, which cyclized thermally to 1,2-oxathiolo[3,4-b]- III and -[4,3-c]pyridine dioxide IV, resp.
Journal of Heterocyclic Chemistry published new progress about 636-73-7. 636-73-7 belongs to pyridine-derivatives, auxiliary class Pyridine,Sulfonic acid, name is Pyridine-3-sulfonic acid, and the molecular formula is C5H5NO3S, Application of Pyridine-3-sulfonic acid.
Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem