Cyclotransformation in the series of monocyclic 3-nitropyridin-2(1<Emphasis Type="Italic">H</Emphasis>)-ones

The interaction of 3-nitropyridine-2(1H)-one and its N′-methyl derivative with hydrazine hydrate leads to the formation of the pyrazole and the carbodihydrazide. 4-Nitropyrazole and the carbodihydrazide are formed from 3,5-dinitropyridine-2(1H)-one and its N′-methyl derivative under similar conditions. The hydrazinolysis of 4-metyl- and 6-metyl-3-nitropyridine-2(1H)-ones provides the 3-methylpyrazole and the carbodihydrazide. A probable mechanism of the process of cyclotransformation of the 3-nitropyridine-2(1H)-ones under hydrazinolysis was suggested.     

Cyclizations of monocyclic 5-nitropyridin-2(1<Emphasis Type="Italic">H</Emphasis>)-ones

Reactions of 5-nitropyridin-2(1H)-one and its N-methyl derivative with hydrazine hydrate led to the formation of (1H-pyrazol-3-yl) acetohydrazide. Under analogous conditions, 1,3-dimethyl-5-nitropyridin2(1H)-one gave rise to 2-(1H-pyrazol-3-yl)propionohydrazide, while 6-methyl-5-nitropyridin-2(1H)-one was converted into (5-methyl-1H-pyrazol-3-yl)acetohydrazide. Hydrazinolysis of 4-methyl-5-nitropyridin-2(1H)-one resulted in the formation of 3-methyl-4-nitro-1H-pyrazole. The mechanism of recyclization of nitropyridine derivatives by the action of hydrazine hydrate was studied using 5-nitropyridin-2(1H)-one and 1-methyl-5-nitropyridin-2(1H)-one as examples.     

Regioselective synthesis of polyfluoroalkyl-substituted 7-(1<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazol-1-yl)-6,7-dihydro-1<Emphasis Type="Italic">H</Emphasis>-indazol-4(5<Emphasis Type="Italic">H</Emphasis>)-ones

3-Polyfluoroalkyl-6,6-dimethyl-7-(1H-1,2,3-triazol-1-yl)-6,7-dihydro-1H-indazol-4(5H)-ones were synthesized with high regioselectivity by 1,3-dipolar cycloaddition of terminal alkynes (phenylacetylene, hex- 1-yne, hept-1-yne, and but-3-yn-1-ol) to 7-azido-6,6-dimethyl-3-polyfluoroalkyl-6,7-dihydro-1H-indazol-4(5H)-ones which were prepared by bromination of 6,6-dimethyl-3-polyfluoroalkyl-6,7-dihydro-1H-indazol- 4(5H)-ones with N-bromosuccinimide in anhydrous carbon tetrachloride, followed by treatment of the corresponding 7-bromo derivatives with sodium azide.     

Carboxamides of Dihydropyridin-2(1<Emphasis Type="Italic">H</Emphasis>)-ones

Summary. 3-Carboxamides and 3-carboxanilides of 6-alkyl and 6-aryldihydropyridin-2(1H)-ones have been prepared via different reaction pathways. All synthesized amides show hydrogen bonds in their NMR spectra. The 4-hydroxy compounds were obtained as a mixture of tautomers. Their configurations were elucidated by NMR experiments.Received December 16, 2002; accepted December 20, 2002 Published online June 2, 2003     

Reaction 5-(Arylmethylidene)pyrimidine-2,4,6(1<Emphasis Type="Italic">H</Emphasis>,3<Emphasis Type="Italic">H</Emphasis>,5<Emphasis Type="Italic">H</Emphasis>)-triones with L-Proline and Aldehydes

Boiling in toluene of 5-(arylmethylidene)pyrimidine-2,4,6(1H,3H,5H)-triones with L-proline and aldehyde led to the formation of previously unknown substituted 1′-arylhexahydro-1H-spiro[pyrimidine-5,2′-pyrrolysine]-2,4,6(1H,3Н,5Н)-triones.     

Synthesis of substituted 3,4-dihydropyrimidin-2(1<Emphasis Type="Italic">H</Emphasis>)-ones and pyrimidin-2(1<Emphasis Type="Italic">H</Emphasis>)-ones by the Biginelli reaction with 3,5-Di-<Emphasis Type="Italic">tert</Emphasis>-butyl-4-hydroxybenzaldehyde

Three-component acid-catalyzed cyclocondensation of 3,5-di-tret-butyl-4-hydroxybenzaldehyde with urea and ethyl acetoacetate or α-nitroacetophenone (Biginelli reaction) under homogeneous conditions gave the corresponding 5-substituted 3,4-dihydropyrimidin-2(1H)-ones having in position 4 of the heteroring an aryl substituent with sterically shielded hydroxy group. The condensation catalyzed by inorganic salts (Fe³⁺, Co²⁺, Zn²⁺, Li⁺) was successful only with ethyl acetoacetate as initial methylene-active component. Under analogous conditions, acetophenone and 4-fluoroacetophenone gave rise to 4,6-diarylpyrimidin-2(1H)-ones which are capable of undergoing phenol-quinonemethide tautomerism.     

Alkylation of 2-(hydroxyimino)-5<Emphasis Type="Italic">H</Emphasis>-[1,3]thiazolo[3,2-<Emphasis Type="Italic">a</Emphasis>]-pyrimidin-3(2<Emphasis Type="Italic">H</Emphasis>)-ones

Alkylation products were obtained from ethyl 2-(hydroxyimino)-7-methyl-3-oxo-5-aryl-2,3- dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidin-6-carboxylates at the treatment with alkyl halides, dimethyl sulfate, and diazomethane. Diazomethane alkylated the initial substrate at the oxygen atom of the carbonyl group of the thiazolidine fragment, the other reagents, at the oxygen atom of the hydroxyimino group.     

Three-component heterocyclization of 5-(arylmethylidene)pyrimidine-2,4,6(1<Emphasis Type="Italic">H</Emphasis>,3<Emphasis Type="Italic">H</Emphasis>,5<Emphasis Type="Italic">H</Emphasis>)-triones with aldehydes and amino acids

Previously unknown substituted 4-aryl-2,7,9-triazaspiro[4.5]decane-6,8,10-triones were synthesized in 50–70% yield by heating 5-(arylmethylidene)barbituric acids with N-methyl- or N-phenylglycine and para-formaldehyde or 4-methoxybenzaldehyde in boiling toluene for 14 h.     

Reaction of 5-arylfuran-2(3<Emphasis Type="Italic">H</Emphasis>)-ones with amines

5-(4-Chlorophenyl)- and 5-phenylfuran-2(3H)-ones reacted with guanidine carbonate at the methylene group in the unsaturated lactone molecule, leading to the formation of 4-(2-aryl-5-oxo-2,5-dihydrofuran-2-yl)-5-aryltetrahydrofuran-2-ones, while 5-(4-methylphenyl)furan-2(3H)-one under analogous conditions gave rise to N,N′-bis[4-(4-methylphenyl)-4-oxobutanoyl]guanidine. The reactions of 5-arylfuran-2(3H)- ones with thioacetamide afforded 4-aryl-N-{1-[5-aryl-2-oxo-2,3-dihydrofuran-3-ylidene]ethyl}-4-oxobutanamides. The corresponding N-(4-aryl-4-oxobutanoyl)thioureas were obtained by heating 5-arylfuran-2(3H)-ones with thiourea.     

Synthesis and biotests of 2-aryl-5-arylmethylidene-substituted 1,3-oxazol-5(4<Emphasis Type="Italic">H</Emphasis>)-ones and <Emphasis Type="Italic">N</Emphasis>-methyl-3,5-dihydro-4<Emphasis Type="Italic">H</Emphasis>-imidazol-4-ones as combretastatin A-4 analogs

A series of 2-aryl-5-arylmethylidene-1,3-oxazol-5(4H)-ones and 2-aryl-5-arylmethylidene-N-methyl-3,5-dihydro-4H-imidazol-4-ones was synthesized as structural analogs of combret- astatin A-4 (a compound possessing antitumor activity). (5Z)-5-[(4-Methoxyphenyl)methyl-idene]-3-methyl-2-(4-methylphenyl)-3,5-dihydro-4H-imidazol-4-one was found to exhibit the highest cytotoxicity against cells of human A549 lung carcinoma line (EC₅₀ = 6±0.8 μmol L^?1).     

Regioselectivity in the reactions of <Emphasis Type="Italic">N</Emphasis>-(polychloroethylidene)-sulfonamides with 1<Emphasis Type="Italic">H</Emphasis>-pyrrole and 1-methyl-1<Emphasis Type="Italic">H</Emphasis>-pyrrole

N-(2,2,2-Trichloroethylidene)arenesulfonamides react with 1H-pyrrole and 1-methyl-1H-pyrrole to give the corresponding N-[2,2,2-trichloro-1-(1H-pyrrol-2-yl)ethyl]arenesulfonamides. The reaction of N-(2,2,2-trichloroethylidene)trifluoromethanesulfonamide with pyrrole leads to a mixture of 2-mono-and 2,5-disubstituted pyrroles, whereas in the reaction with 1-methyl-1H-pyrrole only the 2-substituted compound is formed. N-(2,2-Dichloro-2-phenylethylidene)-4-methylbenzenesulfonamide reacts with 1H-pyrrole to form N-[2,2-dichloro-2-phenyl-1-(1H-pyrrol-2-yl)ethyl]-4-methylbenzenesulfonamide, and its reaction with 1-methyl-1H-pyrrole gives a mixture of 2-and 3-monosubstituted derivatives. The results of quantum-chemical calculations of the initial reactants and products indicate that the process is orbital-controlled. A good agreement is observed between the experimental data and theoretical conclusions concerning the dependence of the reaction regioselectivity on the nature of substituents in the electrophile molecule.     

Chemistry of 2-ylidenefuran-3(2<Emphasis Type="Italic">H</Emphasis>)-ones: XIX. Reaction of 5-aryl-2(oxoylidene)furan-3(2<Emphasis Type="Italic">H</Emphasis>)-ones with carboxylic acid hydrazides

2-[2-(4-Chlorophenyl)-2-oxoethylidene]-5-phenylfuran-3(2H)-one and methyl (5-aryl-3-oxo-2,3-dihydrofuran-2-ylidene)acetates react with carboxylic acid hydrazides to give the corresponding 3-substituted 2-acyl-6-aryl-3-hydroxy-2,3-dihydropyridazin-4(1H)-ones. Specificities of the product structure are discussed.     

Halocyclization of 1-Allyl-6(7)-methylquinolin-2(1<Emphasis Type="Italic">H</Emphasis>)-ones

Oxidation of 1-allyl-6- and -7-methylquinolinium iodides with potassium hexacyanoferrate(III) gave 1-allyl-6(7)-methylquinolin-2(1H)-ones which reacted with halogens to afford 2-halomethyl-7(8)- methyl-1,2-dihydro[1,3]oxazolo[3,2-a]quinolinium halides.     

Reaction of methyl 1-bromocyclopentane- and 1-bromocyclohexanecarboxylates with zinc and 2-arylmethylidene-2,3-dihydro-1<Emphasis Type="Italic">H</Emphasis>-inden-1-ones or 2-arylmethylidene-3,4-dihydronaphthalen-1(2<Emphasis Type="Italic">H</Emphasis>)-ones

Methyl 1-bromocyclopentanecarboxylate and methyl 1-bromocyclohexanecarboxylate reacted with zinc and 2-arylmethylidene-2,3-dihydro-1H-inden-1-ones or 2-arylmethylidene-3,4-dihydronaphthalen-1(2H)-ones to give 4′-aryl-4′,5′-dihydro-2′H-spiro[cyclopentane(cyclohexane)-1,3′-indeno[1,2-b]pyran]-2′-ones or 4-aryl-5,6-dihydrospiro[benzo[h]chromene-3,1′-cyclopentane(cyclohexane)]-2(4H)-ones, respectively.     

Synthesis and study of macroheterocyclic compounds derived from 1<Emphasis Type="Italic">H</Emphasis>-phenalene-1,3(2<Emphasis Type="Italic">H</Emphasis>)-diimine

Symmetrical macroheterocyclic compounds are synthesized by the reaction of 1H-phenalene-1,3(2H)-diimine with m-phenylenediamine, 2,6-diaminopyridine, and 2,5-diamino-1,3,4-thiadiazole. IR and UV spectral data are given.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 8, 2004, pp. 1355–1359.Original Russian Text Copyright © 2004 by Berezina, Vorobev, Vorobeva, Andreikina.This revised version was published online in April 2005 with a corrected cover date.     

Synthesis of 3-alkylquinoxalin-2(1<Emphasis Type="Italic">H</Emphasis>)-ones via Grignard reaction

A two-step procedure has been developed for the synthesis of 3-alkylquinoxalin-2(1H)-ones from o-phenylenediamine and ethyl 2-oxoalkanoates prepared by the Grignard reaction of diethyl oxalate with alkyl bromides. Analogous reaction with α,ω-dibromoalkanes instead of alkyl bromides leads to the formation of 3,3′-(alkane-α,ω-diyl)di[quinoxalin-2(1H)-ones].     

Synthesis of 2-substituted aminothiazol-4(5<Emphasis Type="Italic">H</Emphasis>)-ones proceeding from carboxylactones

New representatives of 2,2,4-trisubstituted butano-4-lactones were synthesized. By a series of transformations the corresponding γ-carboxylactones were obtained. The latter served as starting compounds for preparation of heteryl-linked lactones, 5-[5-{(alkoxymethyl)-2-oxotetrahydrofuran-3-yl}methyl]-2-arylaminothiazol-4(5H)-ones.     

7,8,9-trimethyl-1-phenyl-3<Emphasis Type="Italic">H</Emphasis>-pyrrolo[2,1-<Emphasis Type="Italic">d</Emphasis>][1,2,5]triazepin-4(5<Emphasis Type="Italic">H</Emphasis>)-one. Synthesis and reactions

A strategy was developed for the synthesis of 7,8,9-trimethyl-1-phenyl-3H-pyrrolo[2,1-d][1,2,5]-triazepin-4(5H)-one, reactions of its functionalization at the С⁴ atom and aza rings fusion at the С⁴?N³ bond were explored. The formation mechanism of the pyrrolo-1,2,5-triazepinone scaffold was suggested.     

Recyclization of 1,3-dialkyl-6-nitro-1<Emphasis Type="Italic">H</Emphasis>-imidazo[4,5-<Emphasis Type="Italic">b</Emphasis>]pyridine-2,5(3<Emphasis Type="Italic">H</Emphasis>,4<Emphasis Type="Italic">H</Emphasis>)-diones into imidazole derivatives

Treatment of 5-amino-1,3-dialkyl-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones with sodium nitrite in aqueous HCl gave 1,3-dialkyl-1H-imidazo[4,5-b]pyridine-2,5(3H,4H)-diones which were nitrated with potassium nitrate in sulfuric acid to 6-nitro derivatives, and the latter underwent recyclization into 4-amino-1,3-dialkyl-5-(1H-pyrazol-5-yl)-2,3-dihydro-1H-imidazol-2-ones by the action of hydrazine hydrate.