Synthesis of heterocyclic compounds using ketene dithioacetals케텐디티오 아세탈을 이용한 헤테로고리 화합물의 합성에 관한 연구

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Various $\beta$-ketoamides were conveniently prepared by direct aminolysis of acyl Meldrum``s acids. Aminolysis with substituted anilines underwent smoothly regardless of different substituent effects. Noteworthy was weakly nucleophilic amines such as 2-aminopyridine, and 2-nitroaniline afforded the corresponding $\beta$-ketoamide in excellent yields. In the same manner aliphatic primary and secondary amines underwent aminolysis effectively, even sterically congested diisopropylamine gave the amide without any difficulties. Subsequently $\beta$-ketoamides were transformed into ketene dithioacetal $\alpha$-anilides in high yieds by using carbon disulfide and alkyl halide in the presence of potassium carbonate. Thermal cyclization reaction took place smoothly either by heating ketene dithioacetals in an inert solvent like odichlorobenzene at reflux temperature for 2-4 hr or by direct thermolysis at the temperature slightly above its melting point giving off alkyl mercaptan. After cooling the reaction mixture, cuystalline solid was filtered to give 3-acyl-4-alkylthio-2-(1H)-quinolinones in respectable yields. In the same manner $\beta$-keto amides from amino heterocycles such as aminopyridines and aminopyrimidine were subjected to the condition to make the corresponding ketene dithioacetals. However it was not possible to isolate ketene dithioacetals of aminopyridines since under the condition cyclization took place simultaneously to give the cyclized products. But $\beta$-keto amide from 4.6-dimethyl-2-aminopyrimidine gave the corresponding ketene dithioacetal which was isolated and further cyclized into 3-acetyl-6,8-dimethyl-4-methylthio-2H-pyrimido[1,2-a]pyrimidin-2-one. In an effort to expand its scope, we applied this reaction to the formation of 2(1H)-pyridone skeleton. Thus $\beta$-keto enamides were prepared by adding appropriate $\beta$-ketoester enolate to the substituted trans vinyl isocyanate followed by heating the adduct in DMSO to eliminate carboalk...
Advisors
Pak, Chwang-SiekShim, Sang-Chul박창식심상철
Description
한국과학기술원 : 화학과,
Publisher
한국과학기술원
Issue Date
1992
Identifier
60466/325007 / 000825950
Language
eng
Description

학위논문(박사) - 한국과학기술원 : 화학과, 1992.8, [ vii, 140 p. ]

URI
http://hdl.handle.net/10203/31216
Link
http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=60466&flag=dissertation
Appears in Collection
CH-Theses_Ph.D.(박사논문)
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