Efficient one-pot synthesis of highly substituted pyridin-2(1H)-ones via the Vilsmeier-Haack reaction of 1-acetyl,1-carbamoyl cyclopropanes

A facile and efficient one-pot synthesis of highly substituted pyridin-2(1H)-ones is developed via the Vilsmeier-Haack reaction of readily available 1-acetyl,1-carbamoyl cyclopropanes, and a mechanism involving sequential ring-opening, haloformylation, and intramolecular nucleophilic cyclization reactions is proposed.     

Synthesis of 3-S-hetaryl-substituted pyridin-2(1H)-ones and 5,6-dihydropyridin-2(1H)-ones*

A method has been developed for the synthesis of 3-S-hetaryl-substituted pyridin-2(1H)-ones and 5,6-dihydropyridin-2(1H)-ones based on the base catalyzed cyclization of N-(3-oxoalkyl)- and N-(3-oxoalkenyl)amides which contain a divalent sulfur atom in an α-position to a carbamoyl group and bound to the heterocycle.     

Novel synthesis of 3-aryl-5,6-dihydropyridin-2(1H)-ones

Cyclization of N-3-oxoalkylamides of substituted phenylacetic acids under the influence of bases produces 3-aryl-substituted 5, 6-dihydropyridin-2(1H)-ones. Dehydrogenation of these latter compounds yields substituted pyridin-2(1H)-ones.Omsk State University, Omsk 644077. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 812–815 June, 1994. Original article submitted May 6, 1994.     

Synthesis of 3-arylamino-4(3H)quinazolinone derivatives from 1-acetyl- or 1-ethoxycarbonylmethylene-2-arylhydrazines

By reacting 1-acetyl- or 1-ethoxycarbonylehloromethylene-2-arylhydrazines ( 2a-c ) with anthranilic acids (1a-b) the corresponding C-acetyl- or C-ethoxyearbonylcarbohydrazonamide derivatives (3a-d) were obtained. Ring closure of the carbohydrazonamides with acetic anhydride afforded 2-carboethoxy- or 2-acetyl-3-arylamino-4(3H)quinazolinones ( 4a-d ). The ester derivatives undergo basic hydrolysis with decarboxylation to 3-arylamino-4(3H)quinazolinones ( 5a-b ).     

The synthesis of novel 1-hetarylmethylidene-4-sulfanylfuro-[3,4-c]pyridin-3(1H)-ones

Chemistry of Heterocyclic Compounds - 1-Hetarylmethylidene-4-sulfanylfuro[3,4-c]pyridin-3-ones were accessed from 4-thioxo-4,5-dihydrofuro[3,4-c]pyridin-3(1H)-one employing a condensation reaction...     

Basicities and structures of 4,4,6-trimethyl-2-arylamino-5,6-dihydro-4H-1,3-thiazines and 4,4,6-trimethyl-2-arylamino-5,6-dihydro-4H-1,3-oxazines

The relative basicities of 4,4,6-trimethyl-2-arylamino-5,6-dihydro-4H-1,3-thiazines and 4,4,6-trimethyl-2-arylamino-5, 6-dihydro-4H-1,3-oxazines, which are capable of amine-imine tautomerism, and of model compounds with fixed amine and imine structures were determined by potentiometric titration in methanol. Good correlation of the pK _a values with the Hammett constants in the investigated reaction series was found. The inapplicability of the use of the pK _a values of model compounds for the determination of the tautomeric equilibrium constants in the case of some N-heterocyclic amines of nonaromatic character with an aryl substituent attached to the exocyclic nitrogen atom of the amidine fragment of the molecule is demonstrated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1621–1624, December, 1976.     

A new synthesis of aryl substituted quinazolin-4(1H)-ones

Treatment of a variety of substituted 2-aminobenzonitriles with formic acid under strong acid catalysis provides the corresponding quinazolin-4(1H)-ones in good yield. A potential reaction pathway is described.     

5,6-Dihydropyridin-2(1H)-ones and 5,6-dihydropyridine-2(1H)-thiones (review)

Data on methods for the production of 5,6-dihydropyridin-2(1H)-ones and 5,6-dihydropyridine-2(H)-thiones and their biological activity are reviewed.Omsk State University, Omsk, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 147–167, February, 1999.     

Synthesis of substituted 2-amino-5,6-dihydro-4h-1, 3-oxazines

4,4,6-Trimethyl-2-alkyl(aryl)amino-5,6-dihydro-4H-1,3-oxazines were synthesized via two methods: amination of 4,4,6-trimetiiyl-2-methylthio-5,6-dihydro-4H-1,3-oxazine and cyclization of N-aryl-N-(2-methyl-4-hydroxy-2-amyl)-S-methylisothiourea.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1037–1040, August, 1972.     

Chemical properties of 3,6- and 5,6-dihydro-2H-pyrans (review)

The reactions of 3,6- and 5,6-dihydro-2H-pyrans that are due to the presence of double and ether bonds are correlated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 24, No. 3, pp. 291–304, March, 1988.     

One-pot synthesis of 2-alkyltetrahydropyran-3-ones from 3-nitro-5,6-dihydro-4H-pyran and grignard reagents

3-Nitro-5,6-dihydro-4H-pyran reacts with primary aliphatic and benzylic Grignard reagents and, in suitable hydrolysis conditions, gives the corresponding 2-alkyltetrahydropyran-3-ones in satisfactory yields.     

Synthesis of 5,6-dimethoxyquinazolin-2(1H)-ones

Synthesis of 5,6-dimethoxyquinazolin-2(1H)-one derivatives was the subject of investigations leading to the preparation of title compounds 11, 13, 14 and 26 . Target quinazolines 1 were synthesized in three ways; the route starting from o-vanillin via the intermediacy of 6-amino-2,3-dimethoxyacetophenone ( 19 ) was used for most of the preparative work. The unexpected formation of an acid-labile dimer of 13 was discovered and solid state ¹³C nmr was used for structural assignment. The 5-methoxy substituent in these systems shows anomalous spectral characteristics and, in one case, was cleaved in acid media to 22 .     

Electrospray ionisation and ion-trap fragmentation of substituted 3,4-dihydro-2(1H)-pyridin-2-ones

A variety of 5-alkoxycarbonyl-4-aryl-6-methyl-3,4-dihydro-2(1H)-pyridones and hexahydrofuro[3,4-b]-2(1H)-pyridones have been investigated by electron impact (EI) and electrospray ionisation (ESI) techniques. Sequential product ion fragmentation (MS(n)) was performed to elucidate the degradation pathways for these compounds. Comparisons are made between positive and negative even-electron ions from ESI spectra and the molecular radical cations obtained under EI conditions. The data collected in this paper provide information on the strong impact that different substituents have on the ion fragmentation process.     

AuCl(3)-catalyzed synthesis of highly substituted furans from 2-(1-alkynyl)-2-alken-1-ones

Highly substituted furans have been synthesized by the reaction of 2-(1-alkynyl)-2-alken-1-ones and various nucleophiles under very mild reaction conditions in good to excellent yields. Gold and some other transition metals are efficient catalysts for this reaction.     

Facile synthesis of 6-organyl-4-(trifluoromethyl)pyridin-2(1H)-ones and their polyfluoroalkyl-containing analogs

The three-component cyclization of 3-polyfluoroalkyl-3-oxopropanoates and methyl ketones with ammonium acetate affords 6-organyl-4-(polyfluoroalkyl)pyridin-2(1H)-ones (organyl is alkyl, aryl, or hetaryl). The synthesized pyridones were evaluated for antifungal, antibacterial, and analgesic activity.