Studies on 4-Hydroxycoumarin. VII. Reactions of 4-Hydroxycoumarin with Cationoid Reagents¹

An Improved Synthesis of 4-Chlorocoumarin-3-sulfonyl Chloride and Its Reactions with Different Bidentate Nucleophiles to Give Pyrido[1',2':2,3]- and Thiazino[3',2':2,3]-1,2,4-Thiadiazino[6,5-c]Benzopyran-6-one 7,7-Dioxides

“…Contrary to the abundant literature mentioning the good solubility of alkali-metal salts of sulfonic acids [31], the salts we prepared are not soluble in water and can be easily isolated in nearly quantitative yields from aqueous solutions by simple filtration (Scheme 1). Compound 3 was reported once by Huebner and Link [32], but the product was only characterized by its elemental analysis for sodium. This paper presents the full characterization of 3.…”

Organophosphorus chemistry 30 [1]. The behavior of 4-hydroxycoumarin toward methylenetriphenylphosphoranes (Wittig Reagents) and alkyl phosphites

“…Thus, 1 reacts with 2a via 1B and with 2b,c via 1A. Noteworthy, involvement of the latter form 1A is more frequent than 1B in many other types of condensation reactions [7,8] that produce 3-substituted-4-hydroxycoumarin derivatives (cf. Ref.…”

“…CCC 1042-7163/98/040427-05 chemical methods [5][6][7][8]; none of which, however, has considered the reaction of 1 with organophosphorus reagents that show well-documented activities toward carbonyl functions [9]. In order to fill this gap, we have now studied the behavior of 1 with resonance-stabilized methylenetriphenylphosphoranes (Wittig reagents, 2a-c) as well as with dialkyl phosphonates (3,ab) and trialkyl phosphites (4a,b).…”

Synthesis and biological evaluation of 1‐(4‐hydroxy‐2‐oxo‐2H‐1‐benzopyran‐3‐yl)pyridinium hydroxide inner salt derivatives

“…Benzothiazole amino alcohols, having the side chain at the 6-position, were later found not to be curative and to be highly toxic in mice at 160-640 mgkg (6). A few other inactive benzothiazoles derived from 2-amino-or 2-mercaptobenzothiazole were reported (7).…”