Abdel Bary, Hamed M. published the artcileReaction with coumarin. IV, Synthetic Route of 10543-42-7, the publication is Afinidad (1995), 52(459), 344-6, database is CAplus.
Coumarin-6-sulfonyl chloride (I) reacts with 4-aminobenzenesulfonamide or 2-amino-1,3,4-thiadiazole-5-sulfonamide at the sulfonamido amino group, leaving the amino group attached to the ring unreacted. Reaction of I with 4-aminoacetophenone, or with o-, m-, or p-phenylenediamine, gives corresponding mono- and bis-sulfonamides II or III, resp. II reacts with hydrazine hydrate or phenylhydrazine to yield hydrazones. Ortho-III is cyclized with aldehydes to give benzimidazole derivatives
Afinidad published new progress about 10543-42-7. 10543-42-7 belongs to chlorides-buliding-blocks, auxiliary class Other Aromatic Heterocyclic,Chloride,Sulfonyl chlorides,Ester, name is Coumarin-6-sulfonyl chloride, and the molecular formula is C9H5ClO4S, Synthetic Route of 10543-42-7.
Referemce:
https://en.wikipedia.org/wiki/Chloride,
Chlorides – an overview | ScienceDirect Topics