title: Davis-Beirut reaction: route to thiazolo-, thiazino-, and thiazepino-2H-indazoles.
abstract: Methods for the construction of thiazolo-, thiazino-, and thiazepino-2H-indazoles from o-nitrobenzaldehydes or o-nitrobenzyl bromides and S-trityl-protected 1°-aminothioalkanes are reported. The process consists of formation of the requisite N-(2-nitrobenzyl)(tritylthio)alkylamine, subsequent deprotection of the trityl moiety with TFA, and immediate treatment with aq. KOH in methanol under Davis-Beirut reaction conditions to deliver the target thiazolo-, thiazino-, or thiazepino-2H-indazole in good overall yield. Subsequent S-oxidation gives the corresponding sulfone.
authors.affiliation: Department of Chemistry, University of California , One Shields Avenue, Davis, California 95616, United States.
authors.forename: Kelli M
authors.initials: KM
authors.lastname: Farber
authors.forename: Makhluf J
authors.initials: MJ
authors.lastname: Haddadin
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Kurth
mesh_terms: D001547:Benzaldehydes / Q000138:chemical synthesis* / Q000737:chemistry*; D001593:Benzyl Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D007191:Indazoles / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013843:Thiazines / Q000138:chemical synthesis* / Q000737:chemistry*; D013844:Thiazoles / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D001547:Benzaldehydes; D001593:Benzyl Compounds; D007191:Indazoles; D013843:Thiazines; D013844:Thiazoles