Reactions of 5-Aryl-4-acyl-3-hydroxy-1-cyanomethyl-3-pyrrolin-2-ones with Aromatic Amines

Russian Journal of General Chemistry - Reactions of 5-aryl-4-aroyl-3-hydroxy-1-cyanomethyl-3-pyrrolin-2-ones with aromatic amines in glacial acetic acid afforded...     

Reactions of 1-(4-aminosulfonylphenyl)-5-aryl-4-aroyl-3-hydroxy-3-pyrrolin-2-ones with arylamines and hydrazine hydrate

Depending on the reaction condition, 1-(4-aminosulfonylphenyl)-5-aryl-4-aroyl-3-hydroxy-3-pyrrolin-2-ones reacted with aromatic amines to yield 3-arylamino-3-pyrrolin-2-ones or 4-[aryl (arylamino) methylene]tetrahydropyrrole-2,3-diones. Reactions of 1-(4-aminosulfonylphenyl)-5-aryl-4-aroyl-3-hydroxy-3-pyrrolin-2-ones with hydrazine hydrate afforded pyrrolo[3,4-c]pyrazol-6-ones.     

Synthesis of 5-methoxylated 3-pyrrolin-2-ones via the rearrangement of chlorinated pyrrolidin-2-ones

The reaction of N-substituted 4-methyl-2-pyrrolidinones or 4-diethoxyphosphoryl analogues, carrying at least two chlorine atoms between the C(3) and C(6) carbons, with alkaline methoxide in methanol afforded the corresponding 5-methoxylated 3-pyrrolin-2-ones, useful adducts for the preparation of agrochemicals or medicinal compounds.     

Reactions of 5-aryl-4-acyl-1-(4-hydroxyphenyl)-3-hydroxy-3-pyrrolin-2-ones with arylamines

The reaction of 5-(4-chlorophenyl)-4-benzoyl-1-(4-hydroxyphenyl)-3-hydroxy-3-pyrrolin-2-one with aromatic amines affords the corresponding 3-arylamino derivatives, and the reactions of 5-aryl-4-acetyl-1-(4-hydroxyphenyl)-3-hydroxy-3-pyrrolin-2-ones with p-toluidine yield 5-aryl-4-(1-p-tolylamino)ethylene-1-(4-hydroxyphenyl)pyrrolidin-2,3-diones.     

Synthetic and spectroscopic study of 5-amino-2-acyl-1,2,4-thiadiazolin-3-ones

5-Amino-2-acyl-1,2,4-thiadiazolin-3-ones 2–1 can be synthesized from 5-amino-2H-1,2,4-thiadiazolin-3-one ( 1–1 ) via a selective acylation with an acid anhydride in pyridine. The ¹H nmr spectral characteristics of 5-amino-2-acyl-1,2,4-thiadiazolin-3-ones 2–1 is in particular, compared with 5-amino-2H-1,2,4-thiadiazolin-3-one ( 1–1 ) and 5-amino-2-alkyl-1,2,4-thiadiazolin-3-ones 1–2, 1–3 . The 5-amino group of 2–1 appeared as two peaks in its ¹H nmr spectrum, which merged to a single peak at a higher temperature, while those of compound 1–1, 1–2 and 1–3 appear only as a single peak. The restricted rotation of the C(5)-N(5) (at amino) bond of 5-amino-2-acetyl-1,2,4-thiadiazolin-3-one (2a-1) is about 14.5 Kcal/mol.     

A novel convenient synthesis of 5-acyl-1,2-dihydropyrimidin-2-ones via 4-trichloromethyl-1,2,3,4-tetrahydropyrimidin-2-ones

A novel four-step methodology for the synthesis of 5-acyl-1,2-dihydropyrimidin-2-ones has been developed. The reaction of readily available N-[(1-acetoxy-2,2,2-trichloro)ethyl]ureas with Na-enolates of 1,3-diketones or β-oxoesters followed by heterocyclization-dehydration of the oxoalkylureas formed gave 5-acyl-4-trichloromethyl-1,2,3,4-tetrahydropyrimidin-2-ones. The latter, in the presence of NaH, eliminate CHCl₃ to give the target compounds.     

Synthesis and Bioactivity of 5-Aryl-4-acyl-3-hydroxy-1-[2-(imidazolyl-3-yl)ethyl]3-pyrroline-2-ones

Russian Journal of General Chemistry - 5-Aryl-4-acyl-3-hydroxy-1-[2-(imidazolyl-3-yl)ethyl]-3-pyrroline-2-ones were synthesized by three-component reaction of methyl dioxobutanoates with aromatic...     

New oxidative cyclizations of 1,3,4,6-tetraketones. Synthesis and structure of (Z)-2-acyl-5-alkyl(aryl)-1,4-dioxaspiro[2.4]hept-5-en-7-ones

Iodosobenzene diacetate oxidation of 1,3,4,6-tetraketones 1a-c yielded (Z)-2-acyl-5-alkyl(aryl)-1,4-dioxa-spiro[2.4]hept-5-en-7-ones (4a-c) in addition to 2-acyl-6-alkyl(aryl)-3-hydroxy-4-pyrones (3a-c). The structure of new spiro-heterocycles 4 was inferred from chemical and spectroscopic data, and the stereochemistry was fully defined by a single-crystal X-ray analysis. Alternative cyclization pathways can be rationalized as proceeding through carbocation intermediates derived from both forms of the ring-chain tautomerism of 1,3,4,6-tetraketones 1.     

Synthesis of amino derivatives of 5-aralkylidene-3-pyrrolin-2-ones

Preparation of some derivatives of 5-aralkylidene-3-pyrrolin-2-ones is reported. Compounds with an amino group on the phenyl ring at the 3-position of the pyrrolinone ring showed suitable properties as potential UV-A filters. Some of the compounds were quaternarized to enhance their solubility in aqueous solvents.     

Reactivity of pyrrole pigments. Part 5: Electrophilic substitution—Nitration and bromination—Of some pyrromethenones and 5-arylmethylene-3,4-dimethyl-3-pyrrolin-2-ones

Some 5-arylmethylene-3,4-dimethyl-3-pyrrolin-2-ones react with both bromine and nitronium tetrafluoroborate (NO₂BF₄) to give 5-(aryl)nitromethylene-3-pyrrolin-2-ones and 5-(aryl)bromomethylene-3-pyrrolin-2-ones, respectively. The use of bromine in methanol affords 5-(aryl)bromomethyl-3,4-dimethyl-5-methoxy-3-pyrrolin-2-ones. Whereas pyrromethenones react mainly on the pyrrole ring, ethyl 3,4-demethyl-5-[(3,4-dimethyl-5-oxo-3-pyrrolin-2-yl)methylene]-1H-pyrrole-2-carboxylate reacts as the aryl derivatives, however, with bromine in methanol the addition of two methoxy groups at the exocyclic double bond takes place. 3,4-Dimethyl-5-(2-pyridylmethylene)-3-pyrrolin-2-one does not react with bromine or NO₂BF₄, but reacts as the aryl derivatives with bromine in methanol. The reactivity patterns are in agreement with the theoretical ones obtained from MINDO/3 calculations, using theFukui frontier orbital model. The obtained results are used to explain the reactivity of rubins (biladienes-a,c) and verdins (bilatrienes-a,b,c) in front of electrophiles.Einige 5-Arylmethylen-3,4-dimethyl-3-pyrrolin-2-one reagieren sowohl mit Brom als auch mit Nitroniumtetrafloroborat (NO₂BF₄). Man erhält 5-(aryl)bromomethylen-oder 5-(aryl)nitromethylen-3-pyrrolin-2-one. Bei Verwendung einer methanolischen Bromlösung werden 5-(aryl)bromomethyl-3,4-dimethyl-5-methoxy-3-pyrrolin-2-one gebildet. Pyrromethenone reagieren hauptsächlich am Pyrrolring, Ethyl 3,4-dimethyl-5-[(3,4-dimethyl)-5-oxo-3-pyrrolin-2-yl)methylen]-1H-pyrrol-2-carboxylat hingegen verhält sich wie ein Arylderivat, mit methanolischen Bromlösung jedoch erfolgt Eintritt zweier Methoxygruppen an der exocyclischen Doppelbindung.5-(2-Pyridyl)methylen-3,4-dimethyl-3-pyrrolin-2-on reagiert nicht mit Brom oder NO₂BF₄, wohl aber mit einer methanolischen Bromlösung und verhält sich unter diesen Bedingungen wie ein Arylderivat; 3- und 4-Pyridylderivate verhalten sich analog. Die Reaktivität ist in Übereinstimmung mit theoretischen Werten aus MINDO/3-Rechnungen unter Verwendung des Fukui frontier orbital model. Die Reaktivität von Rubinen (Biladiene-a, c) und Verdinen (Bilatriene-a,b,c) gegenüber Elektrophilen werden im Zusammenhang mit den erhaltenen Resultaten diskutiert.

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Reaktivität der Pyrrolpigmente, 5. Mitt.: Elektrophile Substituierung (Nitrierung und Bromierung) von einigen Pyrromethenonen und 5-Arylmethylen-3,4-dimethyl-3-pyrrolin-2-onen

     

An efficient route to 3-aryl-substituted quinolin-2-one and 1,8-naphthyridin-2-one derivatives of pharmaceutical interest

Reaction of arylacetic ester enolates with 2-alkoxy-4H-3,1-benzoxazin-4-ones offers a short and versatile synthetic route to 3-aryl-4-hydroxyquinolin-2(1H)-ones, through the cyclization of the beta-ketoesters produced. Similar reactions of 4H-pyrido[2,3-d][1,3]oxazin-4-ones with ester enolates afford 1-acyl-4-hydroxy-1,8-naphthyridin-2(1H)-ones in a convenient two-step, one-pot procedure.     

A general approach for the synthesis of 5-substituted-4-amino-pyrrolidin-2-ones and 5-substituted-4-amino-3-pyrrolin-2-ones

Short stereoselective syntheses of both 5-substituted-4-amino-pyrrolidin-2-ones and 5-substituted-4-amino-3-pyrrolin-2-ones from natural α-amino acids are described.     

Room temperature ICl-induced dehydration/iodination of 1-acyl-5-hydroxy-4,5-dihydro-1H-pyrazoles. a selective route to substituted 1-acyl-4-iodo-1H-pyrazoles

A number of new functionally substituted 1-acyl-5-hydroxy-4,5-dihydro-1H-pyrazoles have been prepared in moderate to excellent yields from the corresponding 2-alkyn-1-ones. The resulting dihydropyrazoles undergo dehydration and iodination in the presence of ICl and Li2CO3 at room temperature to provide 1-acyl-4-iodo-1H-pyrazoles.     

Synthesis of 1-Aminocarbonylmethyl-5-aryl-4-aroyl-3-hydroxy-3-pyrroline-2-ones

Russian Journal of General Chemistry - A series of new 1-aminocarbonylmethyl-5-aryl-4-aroyl-3-hydroxy-3-pyrrolin-2-ones has been synthesized through a three-component reaction of aroylpyruvic acid...     

Synthesis and Antimicrobial Activity of 5-(Het)aryl-3-hydroxy-1-hydroxyethyl-4-(thienyl-2-carbonyl)-3-pyrrolin-2-ones

Russian Journal of General Chemistry - A series of novel 5-(het)aryl-3-hydroxy-1-hydroxyethyl-4-(thienyl-2-carbonyl)-3-pyrrolin-2-ones was synthesized by reacting methyl thienyl-2-carbonylpyruvate...     

Short synthesis of 4-aryl-3-pyrrolin-2-ones

A three step, convergent synthesis of 4-aryl-3-pyrrolin-2-ones from a tetramic acid has been developed. The key transformation utilized a Suzuki-Miyaura cross-coupling reaction between a 4-tosyloxy-3-pyrrolin-2-one and an arylboronic acid. This work also provides access to 4-arylpyrrolidin-2-ones, cyclic analogs of γ-aminobutyric acid (GABA). Hydrogenation of 4-(4′-chlorophenyl)-3-pyrrolin-2-one proceeded smoothly to give baclofen lactam.     

Functional rearrangement of polychlorinated pyrrolidin-2-ones to 5-imino-lactams promoted by n-propylamine

The reaction of 4-methyl-pyrrolidin-2-ones, chlorinated at the C(3) and C(6) positions, with n-propylamine constitutes a new method for the preparation of 5-propylimino-pyrrolidin-2-ones or 3-pyrrolin-2-ones in generally good yields. The transformation involves a series of eliminations, substitutions and double bond shifts. This constitutes a remarkable example of a functional rearrangement.     

Acylation of 5-amino-3H-1,3,4-thiadiazolin-2-one

Acylation of 5-amino-3H-1,3,4-thiadiazolin-2-one (2) was undertaken selectively at either the 3-NH position or at 5-amino group depending on reaction conditions. The 3-NH is highly acidic and acylation takes place with acid anhydrides at this position in high yields in the presence of pyridine or triethylamine. The diacylation of both the 3-position and the 5-amino group was only possible via the 5-amino-3-acyl-1,3,4-thiadiazolin-2-one intermediates 4 . Under neutral conditions, acylation only occurs at the 5-amino group with acyl chlorides forming 5-acylamino-3H-1,3,4-thiadiazolin-2-ones 5 . 5-Acetylamino-3H-1,3,4-thiadiazolin-2-one can also be synthesized by the thermal transformation of 5-amino-3-acetyl-1,3,4-thiadi-azolin-2-one in acetic acid.     

Reactions of 4-acyl-1-alkoxyaryl-5-aryl-3-hydroxy-2,5-dihydro-1H-pyrrol-2-ones with nucleophilic reagents

4-Acetyl-1-alkoxyaryl-5-aryl-3-hydroxy-2,5-dihydro-1H-pyrrol-2-ones reacted with amines to give 1-alkoxyaryl-5-aryl-4-(1-R-aminoethylidene)pyrrolidine-2,3-diones. Reactions of amines with 4-benzoyl-substituted analogs involve nucleophilic attack on the C³ atom in the heteroring to produce the corresponding 3-R-amino-1-alkoxyaryl-5-aryl-4-benzoyl-2,5-dihydro-1H-pyrrol-2-ones. Reactions of the title compounds with hydrazine hydrate, regardless on the substituent on C₄, afforded 4-aryl-3-methyl(phenyl)-5-[2(4)-methoxyphenyl]-4,6-dihydropyrrolo[3,4-c]pyrazol-6-ones.     

Reactions of 1,5-diaryl-4-heteroyl-3-hydroxy-3-pyrrolin-2-ones with arylamines and butylamine

1,5-Diaryl-4-[2-thienoyl(furanoyl)]-3-hydroxy-3-pyrrolin-2-ones reacted with aromatic amines to form arylamino-3-pyrrolin-2-ones. Reactions with butylamine occurred via intermediate salt formation followed by their transformation into 3-butylamino-3-pyrrolin-2-ones at heating.