Synthesis and alkylation of new functionally substituted 4,4-dimethylpiperidin-2-ones

The reaction of ethyl isopropylidenecyanoacetate with ethyl 3-amino-3-thioxopropanoate gave rise to ethyl 4,4-dimethyl-6-oxo-2-thioxo-5-cyanopiperidine-3-carboxylate whose alkylation provided ethyl 2-benzylsulfanyl-4,4-dimethyl-6-oxo-5-cyano-1,4,5,6-tetrahydropyridine-3-carboxylate, ethyl 5-benzyl-2-benzylsulfanyl-4,4-dimethyl-6-oxo-5-cyano-1,4,5,6-tetrahydropyridine-3-carboxylate, and ethyl 7,7-dimethyl-5-oxo-6-cyano-3,5,6,7-tetrahydro-2H-thiazolo[3,2-a]pyridine-8-carboxylate.     

Reaction of Zinc Enolates Derived from Substituted 2,2-Dibromobutyrophenones with Ethyl 5,5-Dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylate

Zinc enolates derived from substituted 2,2-dibromobutyrophenones react with ethyl 5,5-dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylate to give ethyl 6-aroyl-6-ethyl-4,4-dimethyl-2-oxo-3-oxabicyclo[3.1.0]-hexane-1-carboxylates mostly as a single geometric isomer.     

Isopropylidenemalononitrile in the synthesis of 2-amino-4,6,6-trimethylcyclohexa-2,4-diene-1,1,3-tricarbonitrile, 6-amino-2-(4-methoxybenzoylmethylsulfanyl)-4,4-dimethyl-1,4-dihydropyridine-3,5-dicarbonitrile, and fused 2-aminopyrans according to Michael

Michael reactions of isopropylidenemalononitrile with cyanothioacetamide (in the presence of 4-methoxyphenacyl bromide), cyclohexane-1,3-dione, and 4-hydroxycoumarin, gave 6-amino-2-(4-methoxy-benzoylmethylsulfanyl)-4,4-dimethyl-1,4-dihydropyridine-3,5-dicarbonitrile, 2-amino-4,4-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile, and 2-amino-4,4-dimethyl-5-oxo-4H,5H-pyrano[3,2-c]-chromene-3-carbonitrile, respectively. In the reaction of isopropylidenemalononitrile with cyanoacetamide, only dimerization product of the former, 2-amino-4,6,6-trimethylcyclohexa-2,4-diene-1,1,3-tricarbonitrile, was isolated. Its structure was proved by X-ray analysis.     

Reaction of N-substituted 2-oxochromen-3-carboxamides with bromoderivatives of zinc enolates prepared from alkyl 2,2-dialkyl-4,4-dibromo-3-oxoalkanoates and zinc

Zinc enolates obtained from ethyl 2,2-dialkyl-4,4-dibromo-3-oxobutanoates and zinc react with N-substituted 2-oxochromen-3-carboxamides forming ethyl 3-{1a-(R³-carbamoyl)-2-oxo-1a,7b-dihydrocyclopropa[c]chromen-1-yl}-2,2-dialkyl-3-oxopropanoate isomer with a Z-position of methine hydrogens. Zinc enolates prepared from alkyl 2,2-dialkyl-4,4-dibromo-3-oxopentanoates and-hexanoates and zinc react with N-substituted 2-oxochromen-3-carboxamides to give rise to esters of 3-{1-alkyl-1a-(R³-carbamoyl)-2-oxo-1a,7b-dihydrocyclopropa-[c]chromen-1-yl}-2,2-dialkyl-3-oxopropanoic acid as isomers with the E-position of the methine proton and the alkyl substituent. The reaction carried out in the presence of small quantities of THF and HMPA leads to the formation of 9c-alkyl-2-R³-9b,9c-dihydro-5-oxa-2-azacyclopenta[2,3]-cyclopropa[1,2-a]naphthalene-1,3,4-triones. Zinc enolates from alkyl 2,2-dialkyl-4,4-dibromo-3-oxopentanoates and-hexanoates and zinc with the secondary amides of 2-oxochromen-3-carboxylic acid form alkyl 3-{2-oxo-1a-(piperidinocarbonyl)-and 3-{6-R¹-1a-(morpholinocarbonyl)-2-oxo-1a,7b-dihydrocyclopropa[c]chromen-1-yl}-2,2-R²,R²-3-oxopropanoates as single geometrical isomers.     

Synthesis of fluorinated 2,6-heptanediones and 2-oxa-6- azabicyclo[2.2.2]octanes from 1,4-dihydropyridines

Electrophilic fluorination of Hantzsch-type 1,4-dihydropyridines with Selectfluor^® led to the formation of new fluorinated 2,6-heptanediones - dialkyl 2,4-diacetyl-2,4-difluoro-3-phenylpentanedioates. Novel 2,6-heptanedione derivatives in reaction with hydrazine hydrate easily form 6-amino-4,7-difluoro-3-hydroxy-1,3-dimethyl-5-oxo-8-phenyl-2-oxa-6-azabicyclo[2.2.2]octanes instead of the corresponding diazepine derivatives. The obtained 2-оxa-6-azabicyclo[2,2,2]octanes are thermally stable at the temperatures below 50°С. At higher temperatures rearrangement of 2-oxa-6-azabicyclo[2,2,2]octanes offers new fluorine-containing pyrazolinone derivatives - alkyl esters of 2-fluoro-2-((4-fluoro-3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-4-yl)(phenyl)methyl)-3-oxobutanoates.     

Heterocyclization of 1,1-dicyano-2-(trifluoromethyl)ethylenes with 1,3,3-trimethyl-3,4-dihydroisoquinoline and its derivatives

1,3,3-Trimethyl-3,4-dihydroisoquinolines react with 1,1-dicyano-2,2-bis(trifluoromethyl)ethylene to give 4-amino-6,6-dimethyl-2,2-bis(trifluoromethyl)-3-cyano-6,7-dihydro-2H-benzo[a]quinolizines. The reaction of 3,3-dimethyl-1-cyanomethylidene-1,2,3,4-tetrahydroisoquinoline and the methyl ester of 3,3-dicyano-2-(trifluoromethyl)acrylic acid leads to 5,5-dimethyl-3-oxo-2-(trifluoromethyl)-2-(dicyanomethyl)-2,3,5,6-tetrahydropyrrolo[2,1-a]isoquinoline.A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1888–1892, August, 1992.     

Di-6R,7R1-4(3H)-Oxo-2-quinazolinyl-substituted Cyclobutanes from Pinic and sym-Homopinic Acids

The corresponding diamides were obtained from reaction of cis-3-carboxy-2,2-dimethylcyclobutylacetic acid (pinic acid) and of cis/trans-3-(carboxymethyl)-2,2-dimethylcyclobutylacetic acid (homopinic acid) dichlorides with two equivalents of 5-bromo-, 4-chloro-, and 4,5-dimethoxyanthranilic acids. Treatment of them with formamide leads to the formation of the corresponding 2,2-dimethyl-3-[4(3H)-oxo-2-quinazolinyl]methyl-1-[4(3H)-oxo-2-quinazolinyl]cyclobutanes and 2,2-dimethyl-1,3-di[4(3H)-oxo-2-quinazolinylmethyl]cyclobutanes.     

Five-membered 2,3-dioxo heterocycles: XCII. Reaction of 3-aroyl-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones with ethyl (2Z)-(3,3-dimethyl-8-oxo-2-azaspiro[4.5]deca-6,9-dien-1-ylidene)ethanoate. Synthesis of bridged analogs of pyrrolizidine alkaloids

3-Aroyl-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones reacted with ethyl (2Z)-(3,3-dimethyl-8-oxo-2-azaspiro[4.5]deca-6,9-dien-1-ylidene)acetate to give ethyl 6′-aryl-2′-(2-hydroxyphenyl)-11′,11′-dimethyl-3′,4,4′,13′-tetraoxospiro[2,5-cyclohexadiene-1,9′-(7′-oxa-2′,12′-diazatetracyclo[6.5.1.0^1,5.0^8,12]tetradec-5′-ene)]-14′-carboxylates whose structure was confirmed by X-ray analysis. The products may be regarded as bridged analogs of pyrrolizidine alkaloids, 7′-oxa-2′,12′-diazatetracyclo[6.5.1.01,5.08,12]tetradecanes.     

Synthesis of some substituted 1,3-thiazolines and 1,3-thiazolidines

Sodium salts of 2, 2-dimethyl-4-mercapto-5-oxo-1,3-thiazoline and 2-oxo-3-mercapto-1-thia-4-azaspiro[4.5]dec-3-ene, obtained from a solvate of sodium cyanodithioformate with three molecules of dimethylformamide, acetone, or cyclohexanone in the presence of morpholine, react with chlorothioformic dimethylamide with the formation of 2,2-dimethyl-5-oxo-4-(dimethylaminothiocarbonylthio)-1,3-thiazoline and 2-oxo-3-(dimethylaminothiocarbonylthio)-1-thia-4-azaspiro[4.5]dec-3-ene, respectively, and during acidolysis by hydrochloric acid they are converted to 2,2-dimethyl-5-oxo-4-thiono-1,3-thiazolidine and 2-oxo-3-thiono-1-thia-4-azaspiro[4.5]decane. The latter compounds are facilely phosphorylated by dialkyl chlorophosphonates at the nitrogen atom. The reaction of the solvate of sodium cyanodithioformate with three molecules of dimethylformamide with chloroacetone in the presence of morpho-line occurs anomalously with the formation of cyanothioformic morpholide.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2590–2593, November, 1990.     

Reactions of 2′-oxo-1′,2′-dihydrospiro[cyclopropane-1,3′-indole]-2,2,3,3-tetracarbonitriles with nucleophiles

2′-Oxo-1′,2′-dihydrospiro[cyclopropane-1,3′-indole]-2,2,3,3-tetracarbonitriles reacted with oxygencentered nucleophiles to form addition products at the cyano groups with conservation of the three-membered ring. Reactions of the title compounds with alcohols required the presence of base catalyst, and the products, 2-amino-4,4-dialkoxy-2′-oxo-1′,2′-dihydrospiro[3-azabicyclo[3.1.0]hex-2-ene-6,3′-indole]-1,5-dicarbonitriles, were converted into the corresponding 2-imino-2′,4-dioxospiro[3-azabicyclo[3.1.0]hexane-6,3′-indole]-1,5-dicarbonitriles and 2,2′,4-trioxospiro[3-azabicyclo[3.1.0]hexane-6,3′-indole]-1,5-dicarbonitriles by the action of acetic and sulfuric acids, respectively. The reactions with ketone oximes occurred in the absence of a catalyst, yielding 2-amino-4,4-bis(alkylideneaminooxy)-2′-oxo-1′,2′-dihydrospiro[3-azabicyclo[3.1.0]hex-2-ene-6,3′-indole]-1,5-dicarbonitriles. The reactions with thiols, aliphatic amines, and anilines were accompanied by opening of the three-membered ring. In the reactions with triphenylphosphine and thiols 2-(2-oxo-2,3-dihydro-1H-indol-3-ylidene)malononitrile was obtained, while morpholine and N,N-dimethylaniline gave rise, respectively, to 3,3-diaryl-and 3,3-dimorpholino-1H-indol-2(3H)-ones and tri- and dicyanoethylene derivatives.     

Condensation reactions of 3-oxo-2-arylhydrazonopropanals with active methylene reagents: formation of 2-hydroxy- and 2-amino-6-substituted-5-arylazonicotinates and pyrido[3,2-c]cinnolines via 6π-electrocyclization reactions

3-Oxo-3-phenyl-2-(p-tolylhydrazono)propanal (1a) undergoes condensation with ethyl cyanoacetate in acetic acid in the presence of ammonium acetate to yield either 2-hydroxy-6-phenyl-5-p-tolylazonicotinic acid ethyl ester (6a) or 2-amino-6-phenyl-5-ptolyl-azonicotinic acid ethyl ester (8), depending on the reaction conditions. Similarly, other 3-oxo-3-aryl-2-arylhydrazonopropanals 1a,b condense with active methylene nitriles 2c,d to yield arylazonicotinates 6b,c. In contrast, 2-[(4-nitrophenyl)-hydrazono]-3-oxo-3-phenyl-propanal (1c) reacts with ethyl cyanoacetate to yield ethyl 6-(4-nitrophenyl)-2-oxo-2,6-dihydropyrido[3,2–c]cinnoline-3-carboxylate (11), via a novel 6π-electrocyclization pathway. Finally, 3-oxo-2-(phenylhydrazono)-3-p-tolylpropanal (1d) condenses with 2a-c to yield pyridazinones 13a-c.     

Reaction of methyl 1-bromocycloalkanecarboxylates with zinc and ethyl 5-aryl-3-oxo-2,2-diethylpent-4-enoates

Methyl 1-bromoalkanecarboxylates react with zinc and ethyl 5-aryl-3-oxo-2,2-diethylpent-4-enoates to form ethyl 2-(10-aryl-6-oxo-7-oxaspiro[4.5]dec-8-en-8-yl)-2-ethylbutanoates and ethyl 2-(5-aryl-1-oxo-2-oxaspiro[5.5]undec-3-en-3-yl)-2-ethylbutanoates.     

Continued investigation of the diazotization and coupling spectrophotometric technique for the determination of aromatic amines with 8-amino-1-hydroxynaphthalene-3,6-disulphonic acid and N-(1-naphthyl)ethylenediamine as coupling agents

Twenty more aromatic amines are determined by the diazotization and coupling spectrophotometric technique, with 8-amino-1-hydroxynaphthalene-3,6-disulphonic acid (H-acid) and N-(1-naphthy)ethylenediamine (N-na) as coupling agents. The following are determined by both methods: 2,4-diaminotoluene, 2-aminobenzotrifluoride, 4-benzoxyaniline, 2,4-dimethyl-6-nitroaniline, 4,5-dimethyl-2-nitroaniline, 2-amino-9-fluorenone, naphthionic acid (sodium salt), 3-aminonaphthalene-2, 7-disulphonic acid (monosodium salt), 2-aminonaphthalene-1-sulphonic acid, 4-aminonaphthalene-1-sulphonic acid and 2,4-dibromoaniline. The following are determined only by the N-na method: 5-aminosalicylic acid, 2-amino-4-nitrophenol, 4-amino-2,6-dichlorophenol hydrochloride, 2,5-dimethoxy-aniline, 4-aminothiophenol, 4,4'-diaminodiphenylmethane, 1-naphthylamine, 4,4'-diaminobiphenyl-2,2'-disulphonic acid and 4,4'-diaminostilbine-2,2'-disulphonic acid. The optimum acidities for the different aromatic amines for the N-na method vary considerably. A number of aromatic amines cannot be determined by either method.     

Reactions of Bisazomethines of the Naphtalene Series with 1,3-Diketones

Bisazomethines prepared from aromatic dialdehydes and 2-naphthylamine were for the first time reacted with the following diketones: 1,3-cyclohexanedione, 5,5-dimethyl-1,3-cyclohexanedione, 5-phenyl-1,3-cyclohexanedione, indandione, and 2,2-dimethyl-1,3-dioxane-4,6-dione was studied. The reactions with 1,3-diketones of the cyclohexane series yield benzophenanthridine derivatives. The reactions with indandione, depending on conditions, give either bisarylideneindandiones or bisdihydrobenzo[f]indenoquinoline. As evidenced by the ^13C NMR and IR spectra, in the case of biphenyl-4,4'-dicarbaldehyde bis[N-(2-naphthyl)imine] and 2,2-dimethyl-1,3-dioxane-4,6-dione, 4,4'-bis(3-oxo-1,2,3,4-tetrahydrobenzo[f]quinolin-1-yl)biphenyl is formed.     

Synthesis and properties of 2-amino-4,6-dimethylnicotinic acid arylamides

It is shown that on boiling 2-amino-4,6-dimethylnicotinic acid arylamides with triethyl orthoformate in acetic anhydride, derivatives of 3-aryl-5,7-dimethyl-4-oxo-3,4-dihydropyrido[2,3-d]pyrimidine are formed. The same compounds are obtained by ternary condensation of ethyl 2-amino-4,6-dimethylnicotinate with triethyl orthoformate and alrylamines. On reaction with urea or ammonium thiocyanate, the ethyl ester or anilides of 2-amino-4,6-dimethylnicothinic acid are converted to 2,4-dioxo- or 4-oxo-2-thio-pyrido[2,3-d]pyrimidines respectively.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1384–1386, October, 1992.     

6,6-Dimethyl-4,8-dioxospiro[2.5]octane-1,1,2,2-tetracarbonitrile in the synthesis of heterocyclic compounds of the 2,3-dihydrofuran and 5,6,7,8-tetrahydro-4h-chromene series

6,6-Dimethyl-4,8-dioxospiro[2.5]octane-1,1,2,2-tetracarbonitrile (III), synthesized by the interaction of tetracyanoethylene with 2-bromo-5,5-dimethyl-1,3-cyclohexanedione, reacts with alcohols and ketoximes to form 2-alkoxy-2-(3-alkoxycarbonyl-2,2-dimethylpropyl)-5-amino-3-dicyanomethylene-4-cyano-2,3-dihydrofurans and 2-alkylidenaminoxy-2-(3-alkylidenaminoxycarbonyl-2,2-dimethylpropyl)-5-amino-3-dicyanomethylene-4-cyano-2,3-dihydrofurans. Compound III with triarylphosphines forms 2-(triarylphosphoranilidenamino)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3,4,4-tricarbonitriles. Chuvash State University, Cheboksary 428015, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 170–181, February, 1998.     

Five-membered 2,3-dioxo heterocycles: XCIII. Spiro heterocyclization of 4,5-diaroyl-1H-pyrrole-2,3-diones with acyclic enamine. Crystalline and molecular structure of substituted 1,7-diazaspiro[4.4]nonane

4,5-Diaroyl-1-aryl-1H-pyrrole-2,3-diones reacted with ethyl 3-amino-3-phenylprop-2-enoate to give ethyl 4-aroyl-1,6-diaryl-3-hydroxy-2-oxo-8-phenyl-1,7-diazaspiro[4.4]nona-3,6,8-triene-9-carboxylates. The crystalline and molecular structures of ethyl 4-benzoyl-3-hydroxy-1-(4-methylphenyl)-2-oxo-6,8-diphenyl-1,7-diazaspiro[4.4]nona-3,6,8-triene-9-carboxylate were determined by X-ray analysis.     

Fusions of pyrido[4′,3′:4,5]thieno[2,3-d]pyrimidines with N-heterocyclic moieties

Versatile 2-thioxopyrimidine-type building blocks ethyl 3-(2-ethoxy-2-oxoethyl)- 4 -oxo-2-thioxo-1,2,3,4,5,6,7,8-octahydropyrido[4′,3′:4,5]thieno[2,3-d]pyrimidine-7-carboxylate ( 4 ) and ethyl 4-oxo-2-thioxo-1,2,3,4,5,6,7,8-octahydropyrido[4′,3′:4,5]thieno[2,3-d]pyrimidine-7-carboxylate ( 8 ) were synthesized from diethyl 2-amino-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3,6-dicarboxylate ( 1 ). Derivatives of linear and angular heterocyclic systems having the imidazole and 1,2,4-triazole ring were obtained from the key intermediates 4 and 8 , respectively.     

新型树形化合物1,3,5-三-[7-(7-甲基-2,2-二-(2,2-二羟甲基-3-羟基丙氧基羰基)-6,8-二氧杂螺[3.5]-壬基)]苯的合成

以丙酮和甲酸乙酯为原料, 在醇钠的作用下合成了1,3,5-三乙酰基苯(1). 1与二溴新戊二醇在酸的作用下发生缩酮化反应, 制成1,3,5-三-(1-甲基-2,6-二氧杂-4,4-二溴甲基环己基)苯(2). 2与5,5-二甲基-4,6-二氧杂-1,3-环己二酮在乙醇钠的作用下合成了1,3,5-三-[7-(7-甲基-2,2-二-乙氧羰基-6,8-二氧杂螺[3.5]-壬基)]苯(3). 将3在氯仿中与季戊四醇进行酯交换反应得到产物1,3,5-三-[7-(7-甲基-2,2-二-(2,2-二羟甲基-3-羟基丙氧基羰基)-6,8-二氧杂螺[3.5]-壬基)]苯(4). 收率为47.7%. 标题化合物及中间产物使用IR, ¹H NMR和MS或元素分析进行了表征.     

Synthesis of Some New Thiazoles and Pyrazolo[1,5-a]pyrimidines Containing an Antipyrine Moiety

Ethyl 2-{2-[4-(2,3-dimethyl-5-oxo-1-phenyl-3-(pyrazolin-4-yl)]-2-cyano-1-(phenylamino)vinylthio}-acetate, 2-[4-(2,3-dimethyl-5-oxo-1-phenyl-(3-pyrazolin-4-yl))(1,3-thiazol-2-yl)]2-(4-oxo-3-phenyl-(1,3-thiazoilidin-2-ylidene))ethanenitrile, 2-[4-(2,3-dimethyl-5-oxo-1-phenyl(3-pyrazolin-4-yl))(1,3-thiazol-2-yl)]-2-(4-methyl-3-phenyl(1,3-thiazolin-2-ylidene))ethanenitrile, 2-(5-acetyl-4-methyl-3-phenyl(1,3-thiazolin-2-ylidene))-2-[4-(2,3-dimethyl-5-oxo-1-phenyl(3-pyrazolin-4-yl))(1,3-thiazol-2-yl)]ethanenitrile, and ethyl 2-(cyano(4-(2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-yl)thiazol-2-yl)methylene)-2,3-dihydro-4-methyl-3-phenylthiazole-5-carboxylate were synthesized by treatment of 2-(4-(2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-yl)thiazol-2-yl)-3-mercapto-3-(phenylamino)-acrylonitrile with appropriate halo ketones or halo esters. Also, 4-{2-[5,7-dimethyl-2-(phenylamino)(7a-hydropyrazolo[1,5-a]pyrimidin-3-yl](1,-thiazol-4-yl)}-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one derivatives were synthesized via reaction of 4-{2-[5-amino-3-(phenylamino)pyrazolin-4-yl](1,3-thiazol-2-yl)}-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one with β-diketone or β-keto ester. All synthesized compound were established by elemental analysis, spectral data, and alternative synthesis whenever possible.