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Die Reaktion der im Titel genannten Chinonimine (I) und des Naphthochinonimins (IX) mit p‐Toluolsulfinsäure, die nach Verfahren A) in Form ihres Natriumsalzes (II) eingesetzt wird, führt zu Produkten der öJ‐Anlagerung, wie z.B. (IV), (VI), (VIII) und (X), der Lö‐Anlagerung, wie z.B. (VII) und/ oder der öß‐Anlagerung, wie z.B. (V).
Unstable 8-p-tolylsulfonylimino-5,8-dihydroquinolin-5-one was generated by oxidation of the corresponding reduced form in acetic acid; it reacted in situ with hydrogen chloride and sodium p-toluenesulfinate to give the corresponding 6-substituted 5-hydroxy-8-aminoquinolines.There are almost no published data on N-substituted 8-imino-5,8-dihydroquinolin-5-ones. An attempt was made to correlate antimalarial activity of 8-amino-6-methoxyquinolines with their ability to undergo oxidation to 8-imino-6-methoxy-5,8-dihydroquinolin-8-ones [1], though the corresponding quinoid metabolites were not isolated by independent synthesis [2] because of their instability. The only stable compound of this series, 6-(4-methoxyphenylamino)-8-(4-methoxyphenylimino)-5,8-dihydroquinolin-5-one was obtained by treatment of 6-piperidino-5,8-dihydroquinoline-5,8-dione with excess p-methoxyaniline in acetic acid [3].In the preceding communications we reported on the reactivity of 8-p-tolylsulfonylimino-5,8-dihydroquinolin-5-one derivatives. We found that reactions of these compounds with nucleophilic reagents are governed by the tosylimino group rather than by the endocyclic nitrogen atom [4,5]. In the present work we made an attempt to synthesize 8-arylsulfonylimino-5,8-dihydroquinolin-5-ones. The initial model compound, 8-p-tolylsulfonylimino-5,8-dihydroquinolin-5-one (I), and its derivatives were synthesized following the reaction sequence shown in Scheme 1. The reaction of 8-nitroquinoline (II) with hydroxylamine hydrochloride in alcoholic alkali afforded 5-amino-8-nitroquinoline (III). The latter was converted into 5-hydroxy-8-nitroquinoline (IV) by alkaline hydrolysis according to a specially developed procedure. For this purpose, nitro compound IV was reduced to 8-amino-5-hydroxyquinoline dihydrochloride (V) with tin(II) chloride in hydrochloric acid. Compound V was treated with p-toluenesulfonyl chloride in methanol in the presence of 2 equiv of pyridine to obtain 8-p-tolylsulfonylamino-5-hydroxyquinoline hydrochloride (VI). Oxidation of tosyl derivative VI with (diacetoxy-l 3 -iodanyl)benzene in acetic acid in the presence of an equimolar amount of sodium acetate afforded quinone imine I as a dark green solid material which gradually dissolved in the reaction mixture, giving rise to a dark blue solution. We failed to isolate quinone imine I as individual substance. Nevertheless, by treatment of the reaction mixture at the moment of formation of quinone imine I precipitate with hydrochloric acid or sodium p-toluenesulfinate dihydrate we succeeded in isolating new compounds, 6-chloro-5-hydroxy-8-p-tolylsulfonylaminoquinoline hydrochloride (VII) and 5-hydroxy-6-p-tolylsulfonyl-8-p-tolylsulfonylaminoquinoline (VIII), respectively.The presence of a substituent in position 6 of the quinoline ring system was proved as follows. The oxidation of salt VII with (diacetoxy-l 3 -iodanyl)benzene under the same conditions as in the generation of quinone imine I gave unstable 6-chloro-8-p-tolylsulfonylimino-5,8-dihydroquinolin-5-one (IX) w...
Quinone Imines with a Fused Azine Ring. Part 1. Synthesis and Hydrochlorination of 5-(p-Tolylsulfonylimino)quinolin-8-one. -The title compound (VI), the first representative of N-arylsulfonylquinone imines of the quinoline series, is prepared in four steps from 8-hydroxyquinoline (I). Its reaction with HCl leads to 7-chloro-quinoline derivative (VII) according to the 1,4-addition pattern. -(BELOV, A. V.; NICHVOLODA, V. M.; Russ. J. Org. Chem. 40 (2004) 1, 93-96; Ukr. State Univ. Chem. Technol., Dnepropetrovsk 320005, Ukraine; Eng.) -R. Staver
Quinoline derivatives R 0410Quinone Imines with a Fused Azine Ring. Part 3. Synthesis and Reactivity of 8-p-Tolylsulfonylimino-5,8-dihydroquinolin-5-one Derivatives. -The title 8-tolylsulfonylimino-5,8-dihydroquinolin-5-one (VII) is generated by oxidation of corresponding, readily available aminoquinolinol (VI). In situ reaction of this unstable quinone imine with hydrogen chloride or sodium p-toluenesulfinate provides access to the new aminoquinolinol derivatives (VIII) and (X), respectively. -(BELOV, A. V.; NICHVOLODA, V. M.; Russ.
Quinone Imines with a Fused Azine Ring. Part 2. Reaction of 5-(p-Tolylsulfonylimino)quinoline-8(5H)-ones with Sodium p-Toluenesulfinate. -Depending on the substituent in the 7-position addition or nucleophilic substitution occurs. -(BELOV, A. V.; NICHVOLODA, V. M.; Russ.
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