82843-14-9Relevant academic research and scientific papers
Chemistry of 5-Alkylamino-4H-thiopyranopyridine-4-ones
Schweiger, Klaus,Habernig, Dietmar,Schramm, Hans-Wolfgang,Zigeuner, Gustav
, p. 79 - 88 (1983)
4-Alkylaminopyridinethiones*HCl (1*HCl) react with bis-trichlorethylmalonate (3) predominantly to 5-alkylamino-4H-thiopyranopyridine-4-ones (6).With alcohols in the presence of acids at 25 deg C 6 undergoes an alcoholysis to the corresponding alkyl-3-(2-thioxo-3-pyridyl)propionates (9).On heating in dilute alkali 6 is hydrolysed via 4-alkylamino-2-thioxopyridylpropylketones (11) to the tautomers, 4-hydroxy-2-thioxopyridylpropylketone (12A) and 2-thioxo-3-(1-hydroxybutenyl)-4-piperidon (12B), resp.On refluxing with alkali the ethyl-pyridylpropionate 9a is cyclisized to the 1-alkyl-1,6-naphthyridine-2(1H)-one (4a), but boiling in ethanolic acid hydrolyses 9a via the pyridylpropionic acid 10 to 4-alkyl-aminopyridylpropylketone (11a).The latter can be transformed via the tautomers 12A, B and 2-methylthio-3-pyridylpropylketone (13) to the 4-hydroxy-3-butyrylpyridone (14A) and its tautomer, 3-(1-hydroxy-butenyl)-piperidine-2,4-diones (14B), resp.The structure of 14A, B is established by reaction of 4-isopropylamino-2(1H)-pyridone (2) with butanoylchloride to the 4-isopropylamino-3-butyrypyridone (15) and hydrolysis of 15 to the tautomers 14A, B. - Keywords: 4-Alkylamino-2(1H)pyridinethiones*HCl, reaction with bistrichlorphenyl-ethylmalonate; Alkyl-3(2-thioxo-3-pyridyl)propionates; 4-Hydroxy-3-butyrylpyridone; 4-Hydroxy-2-thioxopyridylpropylketone; Tautomerism
Reaction of 4-Alkylaminodihydro-2(1H)-pyridinethions and -ones resp. with Bis-trichlorophenyl-ethylmalonate
Zigeuner, Gustav,Schweiger, Klaus,Habernig, Dietmar
, p. 573 - 582 (2007/10/02)
4-Alkylamino-2(1H)-pyridinethiones (1) react with bis-trichlorophenyl-ethylmalonate (3) to give four isomeric products: 5-thioxo-1,6-naphthyridine-2(1H)-ones (4), 7,7-dimethyl-4H-thiopyranopyridine-4-ones (6), 2,2-dimethyl-2H-thiopyranopyridine-5,7-dioles (7) and 2,2-dimethyl-2H-thiopyranopyridine-5(3H)-ones (8).On treatment with alkali the thioxogroup of 4 is hydrolyzed and 1,6-naphthyridinediones (5) are formed.Compound 5 can also be synthesized by heating the alkylaminopyridones (2) together with 3. 6 can be hydrolyzed to 2-thioxo-3-pyridylprop ylketones (12).On treatment with diluted alkali or conc. acid the aminogroup of 7 and 8 is hydrolyzed and 10 is formed.By heating in 20percent NaOH 10 is transformed to the dihydroxymercapto-3-pyridylmethylketone (11). - Keywords: 4-alkylaminodihydro-2(1H)pyridinthiones and -ones; Bis-trichlorphenylmalonate; 2H-Thiopyranopyridine-5,7-dioles; 4H-Thiopyranopyridine-4-ones; 2H-Thiopyranopyridine-5-ones; 5-Thioxo-1,6-naphthyridine-2(1H)-ones
