Features of reaction of aromatic nitro-substituted aldehydes with ketones on the matrix of 2(1<Emphasis Type="Italic">H</Emphasis>)-pyridone

Condensation of nitrobenzaldehydes with 3-acetyl-4,6-dimethyl-2(1H)-pyridone gives rise to chalcones with high yield. Condensation of the close analogs of 3-acetyl-4,6-dimethyl-2(1H)-pyridone containing ethyl and benzyl radical was established to give stable products of aldol condensation, the corresponding alcohols, under the same conditions.     

New,convenient synthesis of 2-alkyl- and 2-vinylpyrazolo[3,4-d]-pyrimidine derivatives

Treatment of 1,3-dimethyl-6-hydrazinouracil with the appropriate dimethylformamide dialkylacetal afforded the, corresponding 2-alkyl-5,7-dimethylpyrazolo[3,4-d]pyrimidine-4,6-(5H,7H)diones. The reaction of 1,3-dimethyl-6-(α-methylbenzylidenehydrazino)uracils with dimethylformamide dimethylacetal or triethyl orthoformate gave the corresponding 5,7-dimethyl-2-vinylpyrazolo[3,4-d]pyrimidine-4,6(5H,7H)diones, respectively. Similarly, treatment of 1,3-dimethyl-6-(α-methylbenzylidenehydrazino)uraeils with triethyl orthopropionate yielded the corresponding 5,7-dimethyl-3-ethyl-2-vinylpyrazolo[3,4-d]pyrimidine-4,6(5H,7H)diones.     

Substituted pyrimidines. II. 1,3-Dimethylisocytosine and related compounds

1,3-Dimethyl-1,2-dihydro-2-imino-4(3H)pyrimidinone (1,3-dimethylisocytosine) was prepared by methylation of 2-amino-3-methyl-4(3H)pyrimidinone and was degraded in alkaline solution to a mixture of 3-methyl-2-methylamino-4(3H)pyrimidinone, 1,3-dimethyl-2,4-(1H,3H)pyrimid-indione, 2-methylamino-l-methyl-4(1H)pyrimidinone, 1-methyl-2,4-(1H,3H)pyrimidindione and 3-methyl-2,4-(1H,3H)pyrimidindione. Thiation of the title compound gave both 1,2-dihydro-1,3-dimethyl-2-thio-4(3H)pyrimidinone and 1,3-dimethyl-2,4-(1H,3H)pyrimidinedithione. The title compound is a tautomerically fixed pyrimidine and its uv spectra were compared with related compounds, notably 3-methyl-2-dimethylarnino-4(3H)pyrimidinone which is also tautomerically fixed.     

Acid-base properties and complex-forming ability of 4,6-dimethyl-2-(1H)-pyrimidinone (thione)

Complex formation of 4,6-dimethyl-2-(1H)-pyrimidinone (thione) with dysprosium(III) tris(acetylacetonate), Dy(acac)₃, in 80% (v/v) aqueous methanol was investigated by pH-metric titration and paramagnetic birefringence. Due to its higher basicity and lower acidity, 4,6-dimethyl-2-(1H)-pyrimidinone is coordinated by Dy(acac)₃ without deprotonation, whereas its thio analog is coordinated in the deprotonated form. Due to the higher acidity of 4,6-dimethyl-2-(1H)-pyrimidinethione, the complex of its anion with Dy(acac)₃ is much more stable than that derived from the oxo analog, as inferred from the comparison of the stability constants.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 855–858, May, 1994.     

Nucleosides and Nucleotides. Part 13. Synthesis and spectral properties of 1- (3′-O-Phosphoryl-2′-deoxy-β -D-ribofuranosyl)-2(1H)-pyridone-(3′-5′)-1-(2′-deoxy-β-D-ribofuranosyl)-2 (1H)-pyridone

The dinucleoside phosphate Π_dpΠ_d ( 4 ) was synthesized from the monomers 1-(5′-O-monomethoxytrityl - 2′ - deoxy - β - D - ribofuranosyl) - 2 (1 H) - pyridone ((MeOTr) Π_d, 2 ) and 1-(5′-O-phosphoryl-3′-O-acetyl-2′-deoxy-β-D -ribofuranosyl)-(1H)-pyridone (pΠ_d(Ac), 3 ). Its 6.4% hyperchromicity and an analysis of the ¹H-NMR. spectra indicate that the conformation and the base-base interactions in 4 are similar to those in natural pyrimidine dinucleoside phosphates.     

Synthesis of 1H-pyrazolo[3,4-c]isoquinolin-1-ones by the condensation of cyclohexanone derivatives with 3-amino-1-phenyl-1H-pyrazol-5(4H)-one

The synthesis of 1H-pyrazolo[3,4-c]isoquinolin-1-ones was carried out by reacting 3-aryl(heteryl)-2,4-diacetyl-5-hydroxy-5-methylcyclohexanones with 3-amino-1-phenyl-1H-pyrazol-5(4H)-one. The structure of the 7-acetyl-2,4,6,7,8,9-hexahydro-8-hydroxy-5,8-dimethyl-2-phenyl-6-(fur-2-yl)-1H-pyrazolo[3,4-c]isoquinolin-1-one obtained was proved by X-ray diffraction analysis.     

Direct introduction of heterocyclic residues into 1,2,4-triazin-5(2H)ones

3-Aryl-1,2,4-triazin-5(2H)-ones 1a-c react with indoles 2a-c in trifluoroacetic acid/chloroform or in boiling butanol or acetic acid to give 3-aryl-6-(indolyl-3)-1,6-dihydro-1,2,4-triazin-5(2H)-ones 3a-g . Oxidation of the dihydro-1,2,4-triazin-5(2H)-ones 3a-e afforded 6-(indolyl-3)-1,2,4-triazin-5(2H)-ones 4a-e , products of nucleophilic substitution of hydrogen in 1a-c . Refluxing 1b with N-methylpyrrote 5b in butanol for an extended time resulted in the formation of 3-(4-chlorophenyl)-6-(1-meuiylpyrrolyl-2)-1,2,4-triazin-5(2H)-one 4h. The reaction of 1a-c with indoles 2a-c , pyrroles 5a,b , 1,3-dimethyl-2-phenylpyrazol-4-one (8) and aminothiazoles 9a,b in acetic anhydride affords the 1-acetyl-3-aryl-6-hetaryl-1,6-dihydro-1,2,4-triazin-5(2H)-ones 6a-s . Reaction of 1a-c with N-methyl-pyrrole 5b in acetic anhydride gives beside the 1:1 addition products 6h-k also the 2:1 addition products 7a-c .     

Synthesis Of Ligands Related To The O-Specific Antigen Of Shigella Dysenteriae Type 1.

Abstract

Stereoselective α-D-galactosylation at the position 3 of 4,6-O-substituted derivatives of methyl 2-acetamido-2-deoxy-α-D-glucopyranoside is described. Glycosyl chlorides derived from 3,4,6-tri-O-acetyl-2-O-benzyl- and 2-O-(4-methoxybenzyl)-D-galactopyranose have been used as glycosyl donors. Methyl 2-acetamido-4,6-di-O-acetyl-2-deoxy-3-O-(3,4,6-tri-O-acetyl-α-D-galactopyranosyl)-α-D-glucopyranoside (27) and methyl 2-acetamido-4,6-di-O-benzyl-2-deoxy-3-O-(3,4,6-tri-O-acetyl-α-D-galactopyranosyl)-α-D-glucopyranoside (31) have been prepared.     

Synthesis of 5-acetyl-4,6-dimethyl-1,2,3,4-tetrahydropyrimidine-2-thione and structural characterization of its polymorphs and complexes with 12-group metal iodides

A novel cyclic thiourea, 5-acetyl-4,6-dimethyl-1,2,3,4-tetrahydropyrimidine-2-thione (L), was synthesized by the reaction of N-(1-tosylethyl)thiourea with potassium enolate of acetylacetone followed by acid-catalyzed dehydration of the obtained 5-acetyl-4-hydroxy-4,6-dimethylhexahydropyrimidine-2-thione. Its polymorphs and complexes with zinc, cadmium, and mercury iodides were studied by X-ray diffraction. Two polymorphs of 5-acetyl-4,6-dimethyl-1,2,3,4-tetrahydropyrimidine-2-thione differ in ring conformation and packing manner. In the monomeric cadmium complex [CdL₂I₂], the central atom is tetrahedrally coordinated in the standard manner by iodine and thiocarbonyl S atoms, while in the dimeric mercury complex [Hg₂L₂I₄], every mercury atom is coordinated by two bridging I atoms, one terminal I atom and one thiocarbonyl S atom of the ligand. In the polymeric zinc complex [ZnLI₂], the zinc tetrahedra are linked by the bidentate bridging 5-acetyl-4,6-dimethyl-1,2,3,4-tetrahydropyrimidine-2-thione molecules through thiocarbonyl S atom and acetyl O atom.     

Syntheses and properties of 4,6-dimelhyl[1,2,5]oxadiazolo[3,4-d]pyrimidine-5,7(4H,6H)dione 1-oxide

New convenient syntheses of 4,6-dimethyl[1,2,5]oxadiazolo[3,4-d]pyrimidine-5,7(4H,6H)-dione 1-oxide (I) from 1,3-dimethyl-6-hydroxylaminouracil by means of nitrosative and nitrative cyclizations are described. Compound I was converted into 4,6-dimethyl[1,2,5]oxadiazolo[3,4-d]pyrimidine-5,7(4H,6H)dione [4,6-dimethyl-5,7(4H,6H)furazano[3,4-d]pyrimidinedione] by refluxing in dimethylformamide. Transformation of I to 1,3,7,9-tetramethyl-2,4,6,8(1H,3H,7H,9H)pyrimido[5,4-g]pteridinetetrone and/or 1,3,6,8-tetramethyl-2,4,7,9(1H,3H,6H,8H)pyrimido[4,5-g]pteridinetetrone is described.     

Pyrimidine derivatives. IX . Synthesis of bromosubstituted 5-nitro-2,4(1H,3H)-pyrimidinedione derivatives

The following 5-nitro-2,4(1H,3H)-pyrimidinediones possessing bromo substituted side chains at the 1- and 6-positions were prepared by bromination of 3,6-dimethyl-1-(ω-hydroxyalkyl)-5-nitro-2,4(1H,3H)-pyrimidinediones 4a and 4b and its nitrates 2a and 2b . The three of mono-bromo derivatives are: 1-(ω-acetoxyalkyl and ω-hydroxyalkyl)-6-bromomethyl-3-methyl. 6a, 6b, 7a and 7b and 1-(ω-bromoalkyl)-3,6-dimethyl-2,4(1H,3H)- pyrimidinediones 8a and 8b . The one type dibromo derivatives are: 1-(ω-bromoalkyl)-6-bromomethyl-3-methyl-2,4(1H,3H)-pyrimidinediones 5a and 5b .     

Bildung von 5,6-Dihydro-1,3(4H)-thiazin-4-carbonsäure-estern aus 4-Allyl-1,3-thiazol-5(4H)-onen

Formation of Methyl 5,6-Dihydro-l, 3(4H)-thiazine-4-carboxyiates from 4-Allyl-l, 3-thiazol-5(4H)-ones . The reaction of N-[1-(N, N-dimethylthiocarbamoyl)-1-methyl-3-butenyl]benzamid ( 1 ) with HCl or TsOH in MeCN or toluene yields a mixture of 4-allyl-4-methyl-2-phenyl-1,3-thiazol-5(4H)-one ( 5a ) and allyl 4-methyl-2-phenyl-1,3-thiazol-2-yl sulfide ( 11 ; Scheme 3). Most probably, the corresponding 1,3-oxazol-5(4H)-thiones B are intermediates in this reaction. With HCl in MeOH, 1 is transformed into methyl 5,6-dihydro-4,6-dimethyl-2-phenyl-1,3(4H)-thiazine-4-carboxylate ( 12a ). The same product 12a is formed on treatment of the 1,3-thiazol-5(4H)-one 5a with HCl in MeOH (Scheme 4). It is shown that the latter reaction type is common for 4-allyl-substituted 1,3-thiazol-5(4H)-ones.     

Manganese(III)-mediated intermolecular cyclization reactions of alkenes and active methylene compounds

The reactions of 1,1-diphenylethene, 1,1-bis(4-chlorophenyl)ethene, 1,1-bis(4-methylphenyl)ethene, and 1,1-bis(4-methoxyphenyl)ethene with 3,5-diacetyl-2,6-heptanedione in the presence of manganese(III) acetate in acetic acid at 80° yielded 4,6-diacetyl-8,8-diaryl-1,3-dimethyl-2,9-dioxabicyclo[4.3.0]non-3-enes (41-48%), 5-acetyl-2,2-diaryl-6-methyl-2,3-dihydrobenzo[b]furans (20–21%), 3-acetyl-5,5-diaryl-2-methyl-4,5-dihydrofurans (5–10%), and benzophenones (3–7%). Similarly, the reactions of 1,1-diarylethenes with dimethyl 2,4-diacetyl-1,5-pentanedioate or diethyl 2,4-diacetyl-1,5-pentanedioate gave the corresponding 4,6-bis(alkoxycarbonyl)-8,8-diaryl-1,3-dimethyl-2,9-dioxabicyclo[4.3.0]non-3-enes in moderate yields.     

Studies on the synthesis of some styryl-3-cyano-2(1H)-pyridinethiones and polyfunctionally substituted 3-aminothieno[2,3-b]-pyridine derivatives

The 3-cyano-4,6-dimethyl-2(1H)-pyridinethione was condensed with benzaldehyde in basic solution leads to styryl-3-cyano-2(1H)-pyridinethiones. Treatment of cinnamicaldehyde with cyanothioacetamide to give cinnamylidencyanothioacetamide, which can be cyclized with the appropriate ketones to afford the 3-cyano-5,6-polymethylene-4-styryl-2(1H)-pyridinethione derivatives. The polyfunctionally substituted 3-aminothieno[2,3-b]pyridine derivatives were obtained in good yield by cyclization of 3-cyano-2(1H)-pyridinethione derivatives with appropriate α-halogeno carbonyl compounds and nitrile, respectively.     

Synthesis and transformations of (±)-trans-4aβ(H), saα(H)-octahydro-4α,7β-dimethyl-2H-1-benzopyran-2-one

Hydrogenation of 4,7-dimethylcoumarin ( 1 ) in alkaline medium has been shown to furnish a mixture of (±)-trans-4aβ(H),8aα(H)-octahydro-4α,7β-dimethyl-2H-1-benzopyran-2-one ( 2 ), (±)-trans-4aβ(H),8aα(H)-octahydro-4α,7α-dimethyl-2H-1-benzopyran-2-one ( 3 ) and (±)-cis-4aα(H),8aα(H)-octahydro-4α,7α-dimethyl-2H-1-benzopyran-2-one ( 4 ) in 40:25:35:ratio, respectively. The stereochemistry of the major hydrogenation product 2 , has been established by transforming it to p-menthane derivatives e.g. (±)-2 (R)-[2′(R)hydroxy-4′(R) methylcyclohex-(1′S)-yl]propan-1-ol ( 20 ) and (±)-trans-3α,6β-dimethyl-3aβ(H),7aα(H)-octahydrobenzofuran ( 12 ). Starting from a mixture of lactones 2, 3 and 4 , lactone 3 has been obtained in pure state employing a sequence of reactions.     

Studies on ketene and its derivatives. CXI . Photoreaction of diketene with 2(1H)-quinolone derivatives

Photoreaction of diketene with 4-methyl-2(1H)-quinolone and 1,4-dimethyl-2(1H)-quinolone gave 2R*,2aR*,SbR*- and 2R*,2aS*8bS*-8b-methyl-3-oxo-1,2,2a,3,4,8b-hexahydrocyclobuta[c]quinoline-2-spiro-2′-(oxetan)-4′-one ( 6a and 6b ), and their 4-methyl derivatives 7a and 7b , respectively. Thermolysis of compounds 6 and 7 afforded 2aR*,8bS*-8b-methyl-2-methylene-3-oxo-1,2,2a,3,4,8b-hexahydrocyclobuta[c]quinoline ( 8 ) and its 4-methyl derivatives 9 , respectively. Similarly, photolysis of diketene and 4-acetoxy-2(1H)-quinolone gave 1R*,2aS*,8bS*- and 1R*,2aR*,8bR*-8b-acetoxy-3-oxo-1,2,2a,3,4,8b-hexahydrocyclobuta[c]-quinoline ( 11a and 11b ). Alcoholysis of compounds 11a and 11b with hydrogen chloride in methanol gave 1-hydroxy-1-(methoxycarbonyl)methylcyclobuta[c]quinoline derivative 12 and 13 which were transformed to 4-acetyl-3-methyl-2(1H)-quinolone ( 15 ) by further alcoholysis. Photoreaction of diketene with 2(1H)-quinolone derivatives gave the corresponding cyclobuta[c]quinoline spirooxetanone derivatives 18 and 23 , which, by thermolysis, were transformed to 2-methylenecyclobuta[c]quinoline 23 and 25 , respectively.     

Ring transformation of 6-methyl-3,4-dihydro-2H-1,3-oxazine-2,4-diones

Ring transformation of 6-methyl-3,4-dihydro-2H-1,3-oxazine-2,4-dione (Ia) and its N-sub-stituted derivatives, such as 3-methyl (Ib), 3-ethyl (Ic), and 3-benzyl (Id) derivatives is described. Reaction of Ia with hydrazine hydrate gave 1-amino-6-methyluracil (II), while Id reacted with hydrazine hydrate to give 3-hydroxy-5-methylpyrazole (III). Reaction of Ia,b,d with ethyl acetoacetate in ethanol in the presence of sodium ethoxide afforded ethyl 3-acetyl-6-hydroxy-4-methyl-2(1H) pyridone-5-carboxylate derivatives (IVa,b,d). On the other hand, reaction of Ib,c,d with ethyl acetoacetate in tetrahydrofuran in the presence of sodium hydride did not give IV, but gave 3-acetyl-1-alkyl-5-(N-alkylcarbamoyl)-6-hydroxy4-methyl-2(1H) pyridone (VIb,c,d). Mechanisms for the formation of compounds IV and VI are discussed.     

A new route to the synthesis of 4-amino-substituted pyrido[2,3-d]pyrimidin-5-one derivatives

The reaction of 6-(R-amino)-5-acetyl-4-methylsulfonyl-2-phenylpyrimidines with amines was studied. 6-Arylamino derivatives react with alkylamines to form 6-alkylamino-4-arylamino-5-acetyl-2-phenylpyrimidines, which upon refluxing in benzene with dimethylformamide dimethylacetal are converted to 4-alkylamino-8-aryl-2-phenylpyrido[2,3-d]pyrimidin-5(8H)-ones. The cyclization proceeds selectively with participation of the arylamino group only, the alkylamino group being not involved. At the same time, refluxing of 5-acetyl-4,6-dibenzylamino-2-phenylpyrimidine with dimethylformamide dimethylacetal in toluene affords the product of condensation on the acetyl group, which upon refluxing in o-xylene transforms to 4-benzylamino-8-benzyl-2-phenylpyrido[2,3-d]pyrimidin-5(8H)-one.

     

Five-membered 2,3-dioxo heterocycles: LXXVI. Reaction of methyl 1-aryl-3-benzoyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates with 6-amino-1,3-dimethylpyrimidine-2,4(1H,3H)-dione

Methyl 1-aryl-3-benzoyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates reacted with 6-amino-1,3-dimethylpyrimidine-2,4(1H,3H)-dione to give methyl 11-aryl-12-benzoyl-9-hydroxy-4,6-dimethyl-3,5,10-trioxo-4,6,8,11-tetraazatricyclo[7.2.1.0^2,7]dodec-2(7)-ene-1-carboxylates which underwent thermal recyclization to 1-aryl-3-benzoyl-4-hydroxy-1′,3′-dimethylspiro[pyrrole-2,5′-pyrrolo[2,3-d]pyrimidine]-2′,4′,5,6′(1H,1′H,3′H,7′H)-tetraones.     

Pyrimidine derivatives. VI. Synthesis of mono-, di-, tri-, and tetrabromo-substituted pyrimidine derivatives

The following bromo-2,4(1H,3H)-pyrimidinediones possessing a bromo substituent at the 5-position and side chains at the 1- and 6-positions were prepared. The three types of mono-bromo derivatives are: 1-(bromoalkyl)-3,6-dimethyl- 3a-d , 5-bromo-3,6-dimethyl-1-(hydroxyalkyl)- 4a-d , and 1-(acetoxyalkyl)-5-bromo-3,6-dimethyl-2,4(1H,3H)-pyrimidinediones 11a-d . The three types of dibromo derivatives are: 5-bromo-1-(bromoalkyl)-3,6-dimethyl- Sa-d , 1-(acetoxyalkyl)-5-bromo-6-bromomethyl- 8a, 8c , and 8d , and 5-bromo-6-bromomethyl 1-(hydroxyalkyl)-2,4(1H,3H)-pyrimidinediones 9a, 9c , and 9d . Likewise one group of tribromo and one group of tetrabromo derivatives are: 5-bromo-1-(bromoalkyl)-6-bromomethyl -7a-d and 5-bromo-1-(bromoalkyl)-6-dibromomethyl-2,4(1H,3H)-pyrimidinediones 6a-d .