Chemistry of iminofurans: XI. Synthesis,structure, and cyclization of 4-substituted 2-(aroylhydrazinylidene)-4-oxobutanoic acids

Aromatic hydrazides reacted with 4-aryl-2-hydroxy-4-oxobut-2-enoic and 2-hydroxy-5,5-dimethyl- 4-oxohex-2-enoic acids to give 4-aryl-2-(2-aroylhydrazinylidene)-4-oxobutanoic and 5,5-dimethyl-2-(aroylhydrazinylidene)- 4-oxohexanoic acids. The products were found to exist in solution as mixtures of Z/E-hydrazinylidene and cyclic dihydropyrazole tautomers, and they underwent intramolecular cyclization to 5-aryland 5-tert-butyl-3-(aroylhydrazinylidene)furan-2(3H)-ones by the action of acetic anhydride.     

Chemistry of iminofurans: V. Synthesis,structure, and cyclization of 4-R-4-oxo-2-[2-(2-oxo-1,2-diphenylethylidene)hydrazino]but-2-enoic acids

Reactions of 1,2-diphenylethane-1,2-dione hydrazone with 4-aryl-2-hydroxy-4-oxobut-2-enoic and 2-hydroxy-5,5-dimethyl-4-oxohex-2-enoic acids provided 4-aryl-4-oxo-2-[2-(2-oxo-1,2-diphenylethylidene) hydrazino]but-2-enoic and 5,5-dimethyl-4-oxo-2-[2-(2-oxo-1,2-diphenylethylidene)hydrazino]hex-2-enoic acids. The acids derivatives can exist in solutions as Z- and β-enehydrazino-or β-ketohydrazone forms, and under the treatment with acetic anhydride they undergo cyclization into 5-aryl- and 5-tert-butyl-3-[2-(2-oxo-1,2-diphenylethylidene)hydrazono]-2,3-furandiones.     

Iminofurans chemistry: IV. Synthesis and structure of 2-<Emphasis Type="Italic">N</Emphasis>-aryl-substituted derivatives of 2-amino-4-aryl-4-oxobut-2-enoic and 2-amino-5,5-dimethyl-4-oxohex-2-enoic acids

Reactions of arylamines with 4-aryl-2-hydroxy-4-oxobut-2-enoic and 2-hydroxy-5,5-dimethyl-4-oxohex-2-enoic acids gave rise to 4-aryl-2-arylamino-4-oxobut-2-enoic and 2-aryl-amino-5,5-dimethyl-4-oxohex-2-enoic acids that existed in solutions as Z- and E-isomers or in a ring form as 3-arylamino-5-tert-butyl-5-hydroxyfuran-2(5H)-ones. The probable cyclization mechanism of these compounds into 5-R-3-arylimino-3H-furan-2-one derivatives was considered.     

Iminofuran chemistry: VII. Intramolecular cyclization of 2-N-aryl-substituted derivatives of 2-amino-4-aryl-4-oxobut-2-enoic and 2-amino-5,5-dimethyl4-oxohex-2-enoic acids

The cyclization at the treatment of acetic anhydride of 4-aryl-2-arylamino-4-oxobut-2-enoic and 2-arylamino-5,5-dimethyl-4-oxohex-2-enoic acids was investigated furnishing derivatives of 5-aryl-3-aryl-imino-3H-furan-2-ones and 4-arylamino-2-tert-butyl-2,5-dihydro-5-oxofuran-2-yl acetate respectively. 2-N²-Methylenesubstituted 4-aryl-2-hydrazino-4-oxobut-2-enoic and 5,5-dimethyl-2-hydrazino-4-oxohex-2-enoic acids cleanly underwent cyclization under the effect of acetic anhydride into 5-aryl-3-hydrazono-3H-furan-2-ones and 5-tert-butyl-3-hydrazono-3H-furan-2-ones.     

Chemistry of iminofurans: VI.* Synthesis and structure of 2-(2-ylidenehydrazino)-substituted 4-aryl-4-oxobut-2-enoic and 5,5-dimethyl-4-oxohex-2-enoic acids

Hydrazones derived from substituted benzophenones and fluorenone reacted with 4-aryl-2-hydroxy-4-oxobut-2-enoic and 2-hydroxy-5,5-dimethyl-4-oxohex-2-enoic acids to give the corresponding 2-(2-ylidenehydrazino) derivatives which may be used as initial compounds for the synthesis of 3-hydrazono-3H-furan-2-ones. The obtained but-2-enoic and hex-2-enoic acid derivatives in solution may exist as Z- and E-isomeric enehydrazine tautomers or hydrazone tautomers with syn or anti orientation of substituents with respect to the double C=N bond.     

Five-membered 2.3-dioxo heterocycles: LXVIII. Three pathways in the reaction of methyl 3-aroyl-1-aryl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates with 3-amino-5,5-dimethylcyclohex-2-en-1-one

Methyl 3-aroyl-1-aryl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates reacted with 3-amino-5,5-dimethylcyclohex-2-en-1-one having no substituent on the nitrogen atom to give 3-aroyl-4-arylamino-6′,6′-dimethyl-6′,7′-dihydro-5H-spiro[furan-2,3′-indole]-2′,4′,5′(1′H,5′H)-triones or methyl 12-aroyl-11-aryl-9-hydroxy-5,5-dimethyl-3,10-dioxo-8,11-diazatricyclo[7.2.1.0^2,7]dodec-2(7)-ene-1-carboxylates. The latter underwent thermal recyclization to 3′-aroyl-1′-aryl-4′-hydroxy-6,6-dimethyl-6,7-dihydrospiro[indole-3,2′-pyrrole]-2,4,5′(1H,1′H,5H)-triones.     

The reactions of aroylpyruvic acids and their derivatives witho-aminophenyldiphenylmethanol

Aroylpyruvic acids and their methyl esters react witho-aminophenyldiphenylmethanol to form 4-aryl-2-[2-(1-hydroxydiphenylmethyl)phenylamino]-4-oxobut-2-enoic acids and their esters. The α-enamino acids obtained undergo intramolecular heterocyclization in the presence of Ac₂O to affort substituted 4,5-dihydrobenzo[e][1,4]oxazepin-3(1H)-ones. The reaction of 5-arylfuran-2,3-diones witho-aminophenyldiphenylmethanol leads to products of decyclization, 2-(1-hydroxydiphenylmethyl)phenylamides of 4-aryl-2-hydroxy-4-oxobut-2-enoic acid, which upon heating in AcOH or Ac₂O yield 3-aroylacetyl-1,1-diphenyl-1H-benzo[d][1,3]oxazines. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2317–2319, November, 1998.     

4-aryl-2-hydroxy-4-oxobut-2-enoic acids <Emphasis Type="Italic">N</Emphasis>-(2-pyridyl)amides in reactions with diazo compounds

Reactions of 4-aryl-2-hydroxy-4-oxobut-2-enoic acids N-(2-pyridyl)amides with diazomethane, diazoethane, diaryldiazomethanes, and diazofluorene lead to the formation of 2-alkoxy-4-aryl-4-oxobut-2-enoic acids N-(2-pyridyl)amides, 3-aroyl-5-methylpyrazole-4-carboxylic acids N-(2-pyridyl)amides, and 3-alkoxy-3-(2-aryl-2-oxoethyl)-2,3-dihydro-2-oxoimidazo[1,2-a]pyridines. The composition and structure of compounds obtained depend on the nucleophilic nature of the diazo compound and on the character of substituents in the aryl and pyridine parts of the substrate.     

Synthesis of 4,6-diaryl-1-benzyl-6-hydroxy-5,5-dimethyl-2-oxopiperidine-3-carbonitriles and their analogs via a modified Reformatsky reaction

Organozinc compounds obtained from 1-aryl-2-bromo-2-methylpropanone and zinc react with N-benzyl-3-aryl-2-cyanoacrylamides or N-[6-(2-cyano-1-oxo-3-phenylprop-2-enylamino)hexyl]-2-cyano-3-phenylacrylamide to give 4,6-diaryl-1-benzyl-6-hydroxy-5,5-dimethyl-2-oxopiperidine-3-carbonitriles or 1,6-bis(6-aryl-3-cyano-6-hydroxy-5,5-dimethyl-2-oxo-4-phenylpiperidyl)hexanes as a single isomer with trans-located piperidine hydrogen atoms.     

A Convenient Synthesis of 3-Aryl-3-(5,5-dimethyl-3-hydroxy-2-cyclohexene-1-one-2-yl) Propanic Esters Catalyzed by KF-Alumina

A series of 3-aryl-3-(5,5-dimethyl-3-hydroxy-2-cyclohexene-1-one-2-yl) propanic esters were synthesized by reaction of aromatic aldehydes, 5,5-dimethyl-1,3-cyclohexanedione and isopropylidene malonate in alcohols catalyzed by KF-Al₂O₃. The structure of 4a was determined by X-ray analysis.     

Synthesis of Alkyl 4-(1-Alkyl-2-aryl-2-oxoethyl)-5,5-dimethyl-2-oxotetrahydrofuran-3-carboxylates

Zinc enolates derived from 1-aryl-2-bromoalkanones react with alkyl 5,5-dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylates to give alkyl 4-(1-alkyl-2-aryl-2-oxoethyl)-5,5-dimethyl-2-oxotetrahydrofuran-3-carboxylates. Reactions of the latter with amines, such as p-toluidine, cyclohexylamine, and piperidine, lead to the corresponding carboxamides.     

Synthesis of some novel chloro-/aryl-substituted-5,5-dimethyl-2-cyclohexenones

Abstract

Two novel structural isomers: the dihalo-5,5-dimethyl-2-cyclohexenones were synthesized. Regioselective Suzuki-Miyaura cross coupling reaction of the isomers with nine different aryl boronic acids afforded eighteen novel compounds: the 2-aryl-3-chloro-5,5-dimethyl-2-cyclohexenones and the 3-aryl-2-chloro-5,5-dimethyl-2-cyclohexenones in 90–95% yields, which were characterized spectroscopically by IR, NMR and MS. The single crystal X-Ray diffraction ORTEP views of four representative compounds unambiguously confirm the formation of substituted cyclohexenones.     

Five-membered dioxo heterocycles: CIV. Reaction of methyl 1-aryl-3-benzoyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates with cyclic enehydrazines. Crystal and molecular structure of N-[3′-benzoyl-1′-(4-chlorophenyl)-4′-hydroxy-6,6-dimethyl-2,4,5′-trioxo-1′,4,5,5′,6,7-hexahydrospiro-[indole-3,2′-pyrrol]-1(2H)-yl]benzamide

Methyl 1-aryl-3-benzoyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates reacted with N′-(5,5-dimethyl-3-oxocyclohex-1-en-1-yl)benzohydrazides and N′-(5,5-dimethyl-3-oxocyclohex-1-en-1-yl)-2,2-diphenylacetohydrazide to give substituted N-[1′-aryl-3′-benzoyl-4′-hydroxy-6,6-dimethyl-2,4,5′-trioxo-1′,4,5,5′,6,7-hexahydrospiro[indole-3,2′-pyrrol]-1(2H)-yl]benz- and -diphenylacetamides.     

Improved synthesis of 3-aralkylidine-5-arylthiophen-2-(3H)ones

3-Aralkylidene-5-arylthiophen-2-(3H)ones can be prepared in two steps from 4-aryl-4-oxobutanoic acids through the intermediacy of butenolides and thiophenones generated by the sequential action of acetic anhydride, sodium hydrosulfide and aromatic aldehydes.     

Synthesis of 6-aryl-1,3-dimethyl-6,7-dihydro-6-azalumazin-7-(6H)ones and their conversion into 2-aryl-1,2,4-triazine-3,5-(2H,4H)odiones. A new synthesis of 1-aryl-6-azauracils

Treatment of 6-amino-5-arylazo-1,3-dimethyluracils with urea or N,N′-carbonyldiimidazole gave the respective 6-aryl-1,3-dimethyl-6,7-dihydro-6-azalumazin-7-(6H)ones, which were hydrolyzed with alkali to afford 2-aryl-2,3,4,5-tetrahydro-3,5-dioxo-1,2,4-triazine-6-carboxylic acids (1-aryl-6-azauracil-5-carboxylic acids). Thermal decomposition of these carboxylic acids gave the corresponding 2-aryl-1,2,4-triazine-3,5-(2H,4H)diones (1-aryl-6-azauracils). Methylation of the latter with methyl iodide gave the corresponding 2-aryl-4-methyl-1,2,4-triazine-3,5-(2H,4H)diones (1-aryl-3-methyl-6-azauracils).     

Five-membered 2,3-dioxo heterocycles: LIV. Double spiro heterocyclization of methyl 1-aryl-3-benzoyl-4,5-dioxo-4,5-dihydro-1<Emphasis Type="Italic">H</Emphasis>-pyrrole-2-carboxylates with 3-arylamino-5,5-dimethylcyclohex-2-en-1-ones

Methyl 1-aryl-3-benzoyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates reacted with 3-arylamino-5,5-dimethylcyclohex-2-en-1-ones in boiling benzene to give the corresponding 1,1′-diaryl-3′-benzoyl-4′-hydroxy-6,6-dimethyl-1,1′,2,4,5,5′,6,7-octahydrospiro[indole-3,2′-pyrrole]-2,4,5′-triones and 1′-aryl-4-arylamino-3-benzoyl-6′,6′-dimethyl-1′,2′,4′,5′,6′,7′-hexahydro-5H-spiro[furan-2,3′-indole]-2′,4′,5-triones whose structure was proved by X-ray analysis.     

Reaction of alkyl 5,5-dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylates with zinc enolates prepared from zinc and 1-arul-2-bromo-2-phenylethanones, 2 bromoindanone, and 2-bromo-6-methyltetralone

Alkyl 5,5-dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylates react with zinc enolates prepared from 1-aryl-2-bromo-2-phenylethanones, 2-bromo indanone, 2-bromo-6-methyltetralone and zinc with formation of ethyl 4-(2-aryl-2-oxo-1-phenyl-ethyl)-5,5-dimethyl-2-oxotetrahydrofuran-3-carboxylates, alkyl 5,5-dimethyl-2-oxo-4-(1-oxoindan-2-yl)tetrahydrofuran-3-carboxylates, and ethyl 5,5-dimethyl-4-(6-methyl-1-oxo-1,2,3,4-tetrahydronaphthalen-2-yl)-2-oxotetrahydrofuran-3-carboxylates respectively, mainly as single diastereomers.     

Synthesis and molecular structure of 3-(2-aryl-2-oxoethyl)-3-methoxy-2-oxo-2,3-dihydroimidazo-[1,2-<Emphasis Type="Italic">a</Emphasis>]pyridine hydrochlorides

Reactions between 2-pyridylamides of Z-4-aryl-2-hydroxy-4-oxobut-2-enoic acids with diazomethane have been used to synthesize 3-(2-aryl-2-oxoethyl)-3-methoxy-2-oxo-2,3-dihydroimidazo[1,2-a]pyridines, which form hydrochlorides with hydrochloric acid. The structure of the latter has been demonstrated by XRD for the hydrochloride of 3-methoxy-2-oxo-3-(2-phenyl-2-oxoethyl)-2,3-dihydroimidazo[1,2-a]pyridine. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 464–468, 2007.     

Synthesis and properties of substituted 2-imidazolidinones

4-Hydroxy- and 4-hydroxylamino-1-hydroxy-3-aryl-5,5-dimethyl-2-imidazolidinones, respectively, were obtained by treatment of N-arylcarbamoyl derivatives of N-(1-oximino-2-methyl-2-porpyl)hydroxylamine with acids and alkalis. 4-Hydroxylaminoimidazolidinones react with p-nitrobenzaldehyde to give nitrones and are converted in acidic media to 4-hydroxy derivatives, which by the action of methanol in the presence of p-toluenesulfonic acid give 4-methoxy-2-imidazolidinones. Acylation and alkylation of 4-hydroxy- and 4-methoxy-2-imidazolidinones take place at the hydroxy group attached to N(₁).Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1255–1261, September, 1976.     

水溶剂中芳醛与5，5－二甲基－1，3－环己二酮的反应

芳醛1与5，5－二甲基－1，3－环己二酮（2）在氯化三乙基苄基铵（TEBA）催 化下在水中生成2，2'－芳业甲基双（3－羟基－5，5－二甲基－2－环己烯－1－酮 ）（3），若在体系中有对甲苯磺酸存在时则生成3，3，6，6－四甲基－9－芳基－ 1，8－二氧代八氢化氧杂蒽（4）或3，3－二甲基－9－（3－羟基－5，5－二甲基 －2－环己烯－1－酮－2－基）－1－氧代四氢代氧杂蒽（6）而不是生成3，产率接 近定量。