N-Methylmorpholinium 4-aryl-5-cyano-3-methoxycarbonyl-2-oxo-1,2,3,4-tetrahydropyridine-6-thiolates: synthesis and properties

Reactions of aromatic aldehydes with cyanothioacetamide and dimethyl malonate in the presence ofN-methylmorpholine affordedN-methylmorpholinium 4-aryl-5-cyano-3-methoxycarbonyl-2-oxo-1,2,3,4-tetrahydropyridine-6-thiolates. The latter were used to synthesize substituted 6-(alkylthio)-2-oxo-1,2,3,4-tetrahydropyridines. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 485–487, March, 2000.     

Reactions of Zinc Enolates Formed from 1-Aryl-2-bromo-2-phenylethanone or 2-Bromoindanone and Zinc,with Dimethyl 2-(1-Arylmethylene)malonates

Zinc enolates formed from 1-aryl-2-bromo-2-phenylethanones and zinc react with dimethyl 2-(1-arylmethylene)malonates to afford dimethyl 2-(1,3-diaryl-3-oxo-2-phenylpropyl)malonates. The latter react with cyclohexylamine, piperidine, or morpholine to give the corresponding monosubstituted amides. The zinc enolate derived from 2-bromoindanone and zinc reacts with dimethyl 2-(4-bromobenzylidene)malonate, yielding dimethyl 2-[(4-bromophenyl)(1-oxoindan-2-yl)methyl]malonate. The final products largely form as a single diastereomer.     

Unexpected Synthesis of Highly Substituted Indole Derivatives

An unexpected synthesis of highly substituted indole derivatives was provided by treating 2-[2-(4-fluorophenyl)-2-oxo-1-phenylethyl]-4-methyl-3-oxo-pentanoic acid phenylamide with aryl hydrazines in the presence of trifluoroacetic acid in tetrahydrofuran.     

Formation of N–S Bonds in Reactions of 2-[2-Oxo-1-(tosyloxyimino)-2-phenylethyl]pyrimidin-4(3<Emphasis Type="Italic">H</Emphasis>)-one and Its 6-derivatives with Thiourea and Potassium Thiocyanate

Reaction of potassium thiocyanate with 2-[2-oxo-1-(1-tosyloxyimino)-2-phenylethyl]pyrimidin-4-(3H)-one derivatives led to the formation of a new fused heterocyclic system with a common nitrogen atom, substituted 7H-[1,2,5]thiadiazolo[2,3-a]pyrimidin-7-one.     

Tandem transformations of bromo-substituted β-(methylsulfonyl)styrenes in reactions with dimethyl malonate,methyl cyanoacetate,and methyl acetoacetate

β-Bromo-β-(methylsulfonyl)styrene reacted with dimethyl malonate and methyl cyanoacetate in the presence of sodium hydride to give sulfonyl-substituted cyclopropanes, and sulfonyl-substituted 2,3-dihydrofuran was also formed in the reaction with methyl acetoacetate. Reactions of α-bromo-β-(bromomethylsulfonyl) styrene with dimethyl malonate and methyl cyanoacetate led to the formation of 2,3-dihydro-λ⁶-thiophene S,S-dioxide derivatives. In the reaction of α-bromo-β-(bromomethylsulfonyl)styrene with methyl acetoacetate, 2,3-dihydro-λ⁶-thiophene S,S-dioxide and 2,5-dihydro-λ⁶-thiophene S,S-dioxide derivatives and methyl acetoacetate O-alkylation product, methyl 3-[(E)-2-(bromomethylsulfonyl)-1-phenylvinyloxy]but-2-enoate, were obtained at a ratio of 2.7: 1.2: 1. α-Bromo-β-(methylsulfonyl)styrene reacted with dimethyl malonate to produce dimethyl 2-[2-(methylsulfonyl)-1-phenylethylidene]malonate. The reaction of β-bromo-β-(bromomethylsulfonyl) styrene with dimethyl malonate and methyl cyanoacetate were strictly stereoselective, and they afforded tetrahydro-λ⁶-thiophene S,S-dioxide derivatives. The reaction of the same substituted styrene with methyl acetoacetate was not stereoselective, and the products were two diastereoisomeric tetrahydro-λ⁶-thiophene S,S-dioxides and sulfonyl-substituted 2,3-dihydrofuran at a ratio of 2.3: 2.7: 1.     

The Preparation of 2-(2-Oxo-2-Phenylethyl) Benzoic Acids from Dilithiated Ortho-Toluic Acid.

ortho-Toluic acid was dimetalated with excess lithium diisopropylamide, and the resulting intermediate was condensed with a variety of aromatic esters to afford new substituted 2-(2-oxo-2-phenylethyl)benzoic acids (ortho-phenacylbenzoic acids).     

Synthesis of 1,2,4-oxadiazines and their rearrangement to pyrimidines

Several amide oximes underwent condensation reactions with dimethyl acetylene dicarboxylate to afford 1:1 adducts. Under basic conditions, these adducts underwent ring closure to afford several methyl [3-(substituted)-4,5-dihydro-5-oxo-6H-1,2,4-oxadiazin-6-ylidene]acetates. The reactions of these compounds with a variety of amines resulted in addition-rearrangement reactions with the formation of the corresponding methyl 2-substituted-5-substituted amino-1,6-dihydro-6-oxo-4-pyrimidine carboxylates.     

Reactions of <Emphasis Type="Italic">N</Emphasis>-(1-chloro-2-oxo-2-phenylethyl) carboxamides with thiosemicarbazide and its derivatives

N-(1-Chloro-2-oxo-2-phenylethyl)acet-, -benz-, and -4-methylbenzamides reacted with thiosemicarbazides and aromatic aldehyde thiosemicarbazones to give derivatives of 5-amino-2-hydrazino-1,3-thiazole. The latter underwent recyclization and acid hydrolysis on heating with hydrochloric acid to produce substituted 3-amino-2-thiohydantoins.     

Heterocyclisation of substituted ylidenethiocarbonohydrazides using dimethyl acetylenedicarboxylate

A facile and rapid procedure for the synthesis of dimethyl-2-[3-amino-5-(2-methoxy-2-oxoethylidene)-4-oxothiazolidin-2-ylidenehydrazono]succinate, dimethyl {[2-alkylidenehydrazono)-5-(2-methoxy-2-oxoethylidene)-4-oxothiazolidin-3-yl)amino]succinate and methyl (4-amino-5-oxo-3-thioxo-2,3,4,5-tetrahydro-1,2,4-triazine-6-yl)acetate affording yields of 61–54 %, 22–18 % and 14–11 %, respectively, via a condensation reaction of dimethyl acetylenedicarboxylate (DMAD) with (substituted ylidene)thiocarbonohydrazides. One of the products was conclusively confirmed by single-crystal X-ray analysis. A mechanism for the formation of the products is presented.     

Asymmetric palladium-catalyzed benzylic nucleophilic substitution: high enantioselectivity with the DUPHOS family ligands

The asymmetric palladium-catalyzed benzylic reaction of 1-(2-naphthyl)ethyl acetate and its 6-methoxy substituted analogue with dimethyl malonate anion led to substitution products with up to 90% ee when the iPr-DUPHOS chiral ligand was used.     

Reactions of zinc enolates derived from 1-aryl-2-bromo-2-phenylethanone and 2-bromoindan-1-one with alkyl 2-oxochromene-and 6-bromo-2-oxochromene-3-carboxylates

Zinc enolates derived from 1-aryl-2-bromo-2-phenylethanone react with alkyl 2-oxochromene-3-carboxylates and methyl 6-bromo-2-oxochromene-3-carboxylate to give, respectively, alkyl 4-(2-aryl-2-oxo-1-phenylethyl)-2-oxochroman-3-carboxylates and methyl 6-bromo-4-(2-aryl-2-oxo-1-phenylethyl)-2-oxochroman-3-carboxylate as a single stereoisomer. Zinc enolates derived from 2-bromoindan-1-one react with alkyl 2-oxochromene-3-carboxylates to give alkyl 2-oxo-4-(1-oxoindan-2-yl)chroman-3-carboxylates as a single stereoisomer.     

Parallel liquid-phase synthesis of N-substituted 6-aminosulfonyl-2-oxo-1,2-dihydroquinoline-4-carboxamide and 6-aminosulfonylquinoline-4-carboxamide derivatives

Two efficient strategies for solution-phase parallel synthesis of libraries of quinoline derivatives are described. The first synthetic pathway features the Pfitzinger reaction of isatin with diethyl malonate and sulfochlorination of the resulting 2-oxo-1,2-dihydroquinoline-4-carboxylate followed by generation of sulfonamide library. The second strategy employs the unusual behavior of 5-sulfamoylisatins in Pfitzinger reactions, which results in formation of 6-sulfamoyl-4-carboxyquinolines instead of the anticipated 2-oxo-1,2-dihydroquinoline structures. The obtained carboxylates appeared to be convenient synthetic intermediates for the generation of the corresponding carboxamide libraries. Using these reagents, the parallel solution-phase synthesis of more than 500 substituted quinoline and 2-oxo-1,2-dihydroquinoline derivatives has been accomplished on the 50-100-mg scale. Simple manual techniques for parallel reactions using special CombiSyn synthesizers were coupled with easy purification procedures to give high-purity final products. The scope and limitations of the developed approaches are discussed.     

Synthesis and crystal structure of <Emphasis Type="Italic">N</Emphasis>(12)-(2-hydroxy-2-phenylethyl)cytisine

Diastereomers of N(12)-(2-hydroxy-2-phenylethyl)cytisine were synthesized by reduction of N(12)-(2-oxo-2-phenylethyl)cytisine by Yamamoto reagent. Their structures were solved using x-ray structure analysis.     

Synthesis, Structure, and Some Properties of Substituted 3-Carbethoxy(methoxy)-5-cyano-1,2,3,4-tetrahydrospirocyclohexane-4-pyridine-2-thiones

The condensation of cyclohexylidenemalononitrile or cyclohexylidenecyanoacetic ester with thioamidoethyl(methyl)malonate in the presence of sodium ethylate gave 6-amino-3-carbethoxy-5-cyano-4-spirocyclohexane-1,2,3,4-tetrahydropyridine-2-thione and 3-carbethoxy(methoxy)-5-cyano-6-oxo-4-spirocyclohexanepiperidine-2-thiones which were used in the synthesis of the corresponding substituted 2-alkylthiotetrahydropyridines. 5-Carbethoxy-3-cyano-3-methyl-6-methylthio-4-spiro-cyclohexane-3,4-dihydropyridine-2(1H)-one was studied by X-ray crystallography.     

Anionic condensations of 3,5-di-<Emphasis Type="Italic">tert</Emphasis>-butyl-4(2)-hydroxybenzaldehydes in the presence of weak bases

Products of the reactions of 4- and 2-hydroxy-3,5-di-tert-butyl-benzaldehydes with malonic acid, diethyl malonate, and acetic anhydride in the presence of weak bases were isolated and identified. The reactions of 3,5-di-tert-butyl-4-hydroxybenzaldehyde with malonic acid and acetic anhydride in the presence of sodium acetate and piperidine gave 3,5-di-tert-butyl-4-hydroxycinnamic acid. The reaction of its 2-hydroxy isomer with acetic anhydride stopped at the stage of formation of the corresponding O-acetyl derivative, while in the reaction with malonic acid the corresponding substituted cinnamic acid and its lactone (coumarin derivative) were formed as intermediate products in a transformation sequence finally leading to 3-(3,5-di-tertbutyl-2-hydroxyphenyl)-3-piperidinopropionic acid and 6,8-di-tert-butyl-2-oxo-3,4-dihydro-2H-chromen-4-ylacetic acid. Analogous differences were typical of reactions of isomeric 4- and 2-hydroxy-3,5-di-tert-butylbenzaldehydes with diethyl malonate. The transformations of the 2-hydroxy isomer were accompanied by hydrolysis and formation of an adduct of intermediate coumarin derivative with diethyl malonate and piperidine.     

Reactions of dialkyl 4-bromo-2,2-dimethyl-3-oxohexane-1,6-dioates,-heptane-1,7-dioates with zinc and aromatic aldehydes

Zinc enolates generated from dimethyl 4-bromo-2,2-dimethyl-3-oxohexane-1,6-dioate and zinc reacted with aromatic aldehydes giving methyl 2,2-dimethyl-3-oxo-3-(5-oxo-2-aryltetrahydrofuran-3-yl)propanoates. The reaction of zinc enolates obtained from dimethyl 4-bromo-2,2-dimethyl-3-oxoheptane-1,7-dioate and zinc with aromatic aldehydes depending on the synthesis conditions led to the formation either methyl 2,2-dimethyl-3-oxo-3-(6-oxo-2-aryltetrahydropyran-3-yl)propanoates or 3-(5,5-dimethyl-4,6-dioxo-2-aryltetrahydropyran-3-yl)propanoates. The compounds synthesized formed as a single diastereomer of E-configuration.     

Preparation of derivatives of 1,2-dihydro- and 1,2,3,6-tetrahydropyrazinones from acylated 1,2-hydroxylamino ketones

N-(2-Oxoalkyl)-2-chloroacetohydroxamic acids were obtained by acylation of 1,2-hydroxylamino ketones with chloroacetyl chloride. Their reaction with urotropin and sodium azide gives urotropinium salts and acetoxyhydroxamic acid azides. 1-Hydroxy-2-oxo-1,2,3,6-tetrahydropyrazines were obtained by treating N-(2-oxoalkyl)-2-chloroacetohydroxyamic acids with ammonia, and also by reacting the urotropinium salts and azides of acetohydroxamic acids with hydrochloric acid and triphenylphosphine, respectively. The reaction of N-(1-methyl-2-oxo-2-phenylethyl)-2-chloroacetohydroxamic acid with urotropin in an acid medium leads to the formation of 6-methyl-2-oxo-5-phenyl-1,2-dihydropyrazine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 509–513, April, 1986.     

Reaction of substituted selenoureas with dimethyl acetylenedicarboxylate

Mono and 1,3-disubstituted selenoureas react with dimethyl acetylenedicarboxylate to give in high yield substituted 3,4-dihydro-4-oxo-2H-1,3-selenazines whose structures were established by speclroscopic methods.     

Microwave Induced Reaction of H-Dimethylphosphonate with Styrene Oxide

Microwave catalyzed reaction of a neat mixture of styrene oxide and H-dimethylphosphonate furnished dimethyl methylphosphonate, trimethylphosphate, phenylacetaldehyde, 1-methoxy-2-phenylethanol, 1-phenylethleneglycol, cis- and trans-1,3-diphenylcyclobutanes, hydrogen 1-(2-phenylethyl)methylphosphinate, (1-phenylethyl)dimethylphosphonate, and (1-phenylethyl)dimethylphosphonate via free radical processes.     

Condensation of γ-bromodypnone with thiocarbamides: Synthesis of 4,4-disubstituted 4,5-dihydro-1,3-thiazol-2-amines and thiazolidin-2-ones

The reaction of 4-bromo-1,3-diphenyl-2-buten-1-one with thiourea or N,N′-diphenylthiourea gives 2-(2-amino-4-phenyl-4,5-dihydro-1,3-thiazol-4-yl)-and 2-[3,4-diphenyl-2-(phenylimino)-1,3-thiazolidin-4-yl]-1-phenyl-1-ethanone — the products of nucleophilic substitution of the halogen atom and Michael addition at position 3 of the 2-buten-1-one system. A similar reaction with thiosemicarbazide and 1-phenylthiosemicarbazide gives the 4-(2-oxo-2-phenylethyl)-4-phenyl-and 4-(2-oxo-2-phenylethyl)-3,4-diphenyl-1,3-thiazolidin-2-one hydrobromides respectively. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 103–110, January, 2008.