Williams, A. C. published the artcileProduct class 4: benzopyranones and benzopyranthiones, Name: Coumarin-6-sulfonyl chloride, the publication is Science of Synthesis (2003), 347-638, database is CAplus.
A review. Methods for preparing 2H-1-benzopyran-2-ones, 4H-1-benzopyran-4-ones, 1H-2-benzopyran-1-ones, 6H-dibenzo[b,d]pyran-6-ones, 9H-xanthenones and their corresponding thione analogs as well as 3H-2-benzopyran-3-ones are surveyed. Synthetic methods include ring closure, ring transformation, aromatization and substituent modification reactions.
Science of Synthesis 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 C5H5ClO2, Name: Coumarin-6-sulfonyl chloride.
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https://en.wikipedia.org/wiki/Chloride,
Chlorides – an overview | ScienceDirect Topics