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Preparation and alkylation of 1,5‐dihydro‐3 H ‐1,2,4‐thiadiazolo[3,4‐ b ]quinazolin‐5‐one 2,2‐dioxides
Author(s) -
Demers James P.,
Sulsky Richard,
Klaubert Dieter H.
Publication year - 1989
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.5570260606
Subject(s) - chemistry , sodium hydride , alkylation , sodium salt , dimethylformamide , sodium , medicinal chemistry , salt (chemistry) , organic chemistry , inorganic chemistry , catalysis , solvent
1,5‐Dihydro‐3 H ‐1,2,4‐thiadiazolo[3,4‐ b ]quinazolin‐5‐one 2,2‐dioxides ( 3 ) are prepared by reaction of isatoic anhydrides with methyl N ‐(chloromethanesulfonyl)carbamimidothioate ( 6 ). The sodium salt of 3a , generated with sodium hydride in N,N ‐dimethylformamide, is alkylated excusively on N‐10. An improved preparation of 6 is described, utilizing a two‐phase sulfonylation.