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Synthesis of pyrazolo[3,4‐ c ][1,2]thiazin‐4(3 H )‐one 2,2‐dioxides, new heterocycles
Author(s) -
Coppo Frank T.,
Fawzi Maged M.
Publication year - 1997
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570340608
Subject(s) - chemistry , sodium hydride , ethyl iodide , pyrazole , methyl iodide , alkylation , iodide , medicinal chemistry , hydride , chloride , sodium iodide , organic chemistry , catalysis , hydrogen
The reaction of substituted ethyl 5‐aminopyrazole‐4‐carboxylates with two equivalents of methanesul‐fonyl chloride gave the substituted ethyl 5‐[bis(methylsufonyl)amino]‐1 H .‐pyrazole‐4‐carboxylates II . Removal of one of the methanesulfonyl groups, followed by alkylation of the ethyl 5‐[(methylsulfonyl)amino]‐1 H ‐pyrazole‐4‐carboxylates III with methyl iodide produced the substituted ethyl 5‐[methyl(methylsulfonyl)amino]‐1 H ‐pyrazole‐4‐carboxylates IV . Treatment of IV with sodium hydride gave the 7‐substituted 1,7‐dihydro‐1‐methylpyrazolo[3,4‐c][1,2]thiazin‐4(3 H )‐one 2,2‐dioxides V .