Condensed Isoquinolines. 12. Synthesis of Novel Heterocyclic Systems Containing a Partially Hydrogenated Spiro[isoquinoline-4,4'-(2H)-pyran] Fragment

By condensation of 4-(2-bromomethyl)-3,4,5,6-tetrahydro-2H-pyran-4-carbonitrile with anthranilic acid, its derivatives substituted in the benzene ring (esters, nitrile), and with esters of 2-aminothiophene-3-carboxylic acids and 3-amino-5-bromobenzofuran-2-carboxylic acid there have been synthesized novel derivatives which include spiro-linked tetrahydropyran and 5,10-dihydro-3H-pyrimido[1,2-b]isoquinoline fragments. The pyrimidine ring of the latter was annelated by a substituted benzene, thiophene, or 5-bromobenzofuran ring.     

Dehydrogenation of 4-aryl(hetaryl) spinacine derivatives with dimethyl sulfoxide

Aromatization of 4-aryl(hetaryl)tetrahydroimidazo[4,5-c]pyridine-6-carboxylic acids and their lithium salts by the action of dimethyl sulfoxide has been revealed for the first time. Heating of these compounds in DMSO for 5–7 h at 90–95°C leads to the formation of 4-aryl(hetaryl)imidazo[4,5-c]pyridine derivatives as a result of dehydrogenation and decarboxylation. Heating of the corresponding lithium salts generated in situ (DMSO, 90–95°C, 3–5 h) affords difficultly accessible 4-aryl(hetaryl)imidazo[4,5-c]pyridine-6-carboxylic acids.     

Microwave-assisted synthesis of 2-aminothiophene-3-carboxylic acid derivatives, 3H-thieno[2,3-d]pyrimidin-4-one and 4-chlorothieno[2,3-d]pyrimidine

A two-minute microwave irradiation allowed the synthesis of several 2-aminothiophene-3-carboxylic acid derivatives. Their efficient transformation to thieno[2,3-d]pyrimidin-4-one and the corresponding 4-chloro derivative is also reported under microwave irradiation.     

Quantum chemical studies of pyrimidin-4-ones Part 6. On peculiarities of the reactions with nitrating agents of some carboxylic acids of the thieno[2,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidin-4-one series and their esters

Quantum chemical calculations of the energies, electronic structures, and molecular geometries of 5-methyl-, 2,5-dimethyl-, 3,5-dimethyl-, and 2,3,5-trimethyl-4-oxothieno[2,3-d]pyrimidine-6-carboxylic acids; 5-methyland 3,5-dimethyl-2,4-dioxothieno[2,3-d]pyrimidine6-carboxylic acids; 5-methyland 3,5-dimethyl-4-oxo-2-thiothieno[2,3-d]pyrimidine-6-carboxylic acids; and their ethyl esters were performed in terms of the HF and DFT (B3LYP) approximations in the 3-21G basis set. The reactions routes with nitrating agents were examined, and the factors governing the direction of the reactions, the probability of their occurrence were determined. Selective ipso-substitution of the 5-methyl group by the nitro group at the C(5) atom of the thiophene fragment is hindered for all compounds studied. The reasons for the unfavorable ipso-substitution were discussed taking into account effects of solvents and substituents in positions 2, 3, and 6 of 6-carboxyand 6-ethoxycarbonyl-substituted thieno[2,3-d]pyrimidin-4-ones.     

One-stage synthesis of condensed pyrimidines by reaction of substituted 3-(pyrimidin-5-yl)propanoic acids with <Emphasis Type="Italic">ortho</Emphasis>-diamines: Extension of limits

By condensation of 2-aryl-substituted pyrimidin-5-ylpropanoic acids with 1,2-ethanediamine and 1,2-benzenediamine in polyphosphoric acid new derivatives of heterocyclic systems were synthesized: imidazo- and benzo[4',5']imidazo[1',2':1,6]pyrido[2,3-d]pyrimidines. Unlike that the reaction of substituted 2-mercaptopyrimidin-5-ylpropanoic acid with 1,2-benzenediamine in polyphosphoric acid in the presence of equimolar amount of ZnCl₂ proceeds by a tandem mechanism with the formation of 4-methyl-5,6-dihydrobenzo[4',5']imidazo[1',2':1,6]pyrido[2,3-d]pyrimidine-2-thiol and the corresponding disulfide.     

A Convenient Synthesis for Some New Pyrido[4′,3′:4,5]thieno[2,3-d]pyrimidines and Related Fused 1,2,4-Triazolo and 1,3,4-Thiadiazolo-derivatives

Diethyl 2-isothiocyanato-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3,6 dicarboxylate 1 is a convenient and useful starting matrial for the constructions of heterocyclic systems. It was utilized to synthesize derivatives of the novel heterocyclic systems pyrido[4',3':4,5]thieno[2,3-d]pyrimidine 4 , 10 , pyrido[4',3':4,5]thieno[2,3-d]-[1,2,4]triazolo[1,5-a]pyrimidine 7 , 11a-e and pyrido[4',3':4,5]thieno[2,3-d][1,3,4]thiadiazolo[3,2-a]pyrimidine 12-14 .     

Positional isomers of thienopyrimidinones

Condensation of o-cyanomethylbenzoic acids with esters of 2-aminothiophene-3-carboxylic and 3-amino-thiophene-2-carboxylic acids to give isomeric 2-(4-oxo-3,4-dihydrothieno[2,3-d]pyrimidin-2-ylmethyl)-benzoic acids and their ethyl and phenacyl esters. Methylation of esters occurs at N-3. The spectroscopic characteristics of the positional isomers are compared at the level of carboxylic acids, their esters, and methylated products. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, 932–941, June, 2008.     

Investigation of nitrogen- and sulfur-containing heterocycles

The reaction of o-aminomercapto derivatives of pyrimidine, pyrazine, and pyridine, with -halo acid nitriles was investigated. The corresponding cyanoalkylthio heterocycles, which were converted to 6-amino derivatives of pyrimido[4,5-b]-, pyrazino[2,3-b]-, and pyrido-[2,3-b]-1,4-thiazines, were obtained. The structures of the substances obtained were confirmed by IR, UV, and PMR spectroscopy.See [10] for communication XXII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 944–948, July, 1972.     

Synthese von 2,4-Diamino-thieno[2,3-d]pyrimidin-Derivaten

Synthesis of 2,4-Diamino-thieno[2,3-d]pyrimidines Condensation of 2-aminothiophene-3-carbonitrile ( 4 ) with guanidine or sequential addition of CS₂ and NH₃ to 4 provides 2,4-diaminothieno[2,3-d]pyrimidine ( 7 ). This compound yields, after sequential addition of sec-BuLi and either [3-(trifluoromethyl)benzene]sulfenyl chloride ( 8 ) or the corresponding disulfide 9 , followed by acidic work up, 2,4-diamino-6-{[3-(trifluoromethyl)phenyl]thio}thieno[2,3-d]pyrimidine ( 10 ). In another approach, 2-amino-5-{[3-(trifluoromethyl)phenyl]thio}thiophene-3-carbonitrile ( 11 ) obtained from 4 and 8 is transformed to 10 by condensation with guanidine. Corresponding to the second route, 2,4-diamino-6-[(naphth-2-yl)thio]thieno-[2,3-d]pyrimidine ( 16 ) is synthesized. Oxidation of 10 with m-chloroperbenzoic acid gives 2,4-diamino-6-{[3-(tri-fluoromethyl)phenyl]sulfinyl}thieno[2,3-d]pyrimidine ( 13 ).     

A convenient synthesis of new pyrido[3,2-e][1,4]diazepine-2,5-diones and pyrido[2,3-e][1,4]diazepine-2,5-diones

A convenient synthesis of a series of pyrido[3,2-e][1,4]-diazepine-2,5-diones 8 and pyrido[2,3-e][1,4]diazepine-2,5-diones 9, is reported using the condensation of α-amino acid methyl ester derivatives with 1H-pyrido[3,2-d][1,3]oxazine-2,4-dione and 1H-pyrido[2,3-d][1,3]oxazine-2,4-dione. Compounds 8 and 9 were also synthesized by peptide coupling of α-amino acid methyl ester derivatives with β-amino acids (2 or 3) followed by the cyclisation in tetrahydrofuran with sodium hydride (NaH).     

Exploring the scope of the Gewald reaction: Expansion to a four-component process

An efficient four-component reaction was developed to take advantage of the reactivity of the 2-aminothiophene-3-carbonitrile functionality, which is obtained during the classical three-component Gewald reaction. Various α-methylene bearing ketones were reacted with malononitrile, elemental sulfur, and aryl/heteroarylnitrile derivatives in t-BuOH/NaOH to afford 2-arylthieno[2,3-d]pyrimidin-4-amines in high yields. Preliminary studies revealed the photophysical properties of the products and their potential for use as metal sensors.     

Synthesis of 1-(1,3-dialkyl-2-oxo-2,3-dihydro-1<Emphasis Type="Italic">H</Emphasis>-imidazo-[4,5-<Emphasis Type="Italic">b</Emphasis>]pyridin-5-yl)-5-oxopyrrolidine-3-carboxylic acids

Nitration of 2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-one gave its 5-nitro derivative which was subjected to alkylation with dimethyl sulfate, diethyl sulfate, and benzyl(dimethyl)phenylammonium chloride. The resulting 1,3-dimethyl-, 1,3-diethyl-, and 1,3-dibenzyl-5-nitro-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones were reduced to the corresponding 1,3-dialkyl-5-amino-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones, and the latter reacted with itaconic acid to produce 1-(1,3-dialkyl-2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-5-yl)-5-oxopyrrolidine-3-carboxylic acids. 1-(2-Oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-5-yl)-5-oxopyrrolidine-3-carboxylic acid was obtained by analogous reaction with 5-amino-2,3-dihydro-1H-imidazo[4,5-b]-pyridin-2-one.     

Synthesis of 5-amino derivatives of ethyl 2-methylthiothieno-[2,3-d]pyrimidine-6-carboxylate and their reaction with hydrazine

A study has been made of the reaction of the ethyl esters of 5-amino-, 5-ethoxy-methyleneamino-, and 5-acetylamino-2-methylthiothieno[2,3-d]pyrimidine-6-carboxylic acids with hydrazine. Certain derivatives of 3-aminothieno[2,3-d4,5-d']-dipyrimidin-4(3H)-ones have been synthesized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1131–1134, August, 1987.     

Thienooxazolopyrimidinium salts. Reaction of 1-bromomethyl-5-oxo-4-phenyl-1,2,4,5,6,7,8,9-octahydro[1]benzothieno-[3,2-<Emphasis Type="Italic">e</Emphasis>][1,3]oxazolo[3,2-<Emphasis Type="Italic">a</Emphasis>]pyrimidin-11-ium bromide with oxygen-centered nucleophiles

Reactions of [1]benzothieno[3,2-e][1,3]oxazolo[3,2-a]pyrimidin-11-ium bromide with oxygen-containing nucleophiles involve opening of the dihydrooxazole ring and lead to the formation of new functionally substituted thieno[2,3]-d]pyrimidine derivatives.     

Three-component reaction of 5-aryl-4-(quinoxalin-2-yl)-furan-2,3-diones,acetylenedicarboxylic acid dimethyl ester,and triphenylphosphine

Three-component synthesis from 5-aryl-4-(quinoxalin-2-yl)furan-2,3-diones, acetylenedicarboxylic acid dimethyl ester, and triphenylphosphine afforded methyl esters of 1,6-dioxaspiro[4.4]nona-3,7-diene-4-carboxylic and 4H-furo[3,2-c]pyran-3-carboxylic acids.     

Synthesis of new polydentate tweezers ligands of amido-amine type

A series of new tweezers amido-amine ligands containing pyrrole, bipyrrole, and dipyrrolylmethane fragments were synthesized by reaction of 2-thioxothiazolidin-3-yl derivatives of α-pyrrolecarboxylic acids {5-[1-(5-carboxy-3-methyl-4-phenyl-1H-pyrrol-2-yl)-1-methylethyl]-4-methyl-3-phenyl-1H-pyrrole-2-carboxylic acid, 5-[(5-carboxy-3-methyl-4-phenyl-1H-pyrrol-2-yl)phenylmethyl]-4-methyl-3-phenyl-1H-pyrrole-2-carboxylic acid, 5-(5-carboxy-3-methyl-4-phenyl-1H-pyrrol-2-yl)-4-methyl-3-phenyl-1H-pyrrole-2-carboxylic acid, and 3,4-dimethyl-pyrrole-2,5-dicarboxylic acid} with o-phenylenediamine. All compounds obtained were characterized by elemental analysis, NMR and mass spectra.     

Synthesis of 5‐mono‐ and 5,7‐diamino‐pyrido[2,3‐d]‐pyrimidinediones with potential biological activity by regioselective amination

5‐Alkyl‐/arylamino‐ and 5,7‐dialkyl/arylamino‐pyrido[2,3‐d]pyrimidine‐2,4‐diones ( 4,5, 7‐9 ) were prepared from the corresponding 5,7‐dichloro‐pyrido[2,3‐d]pyrimidine‐2,4‐diones 2 with aliphatic and aromatic amines 3 and 6 in a regioselective reaction. The 7‐monoazides 10 , obtained by azidation of 5‐amino‐7‐chloro derivatives 4 , were converted to iminophosphoranes by reaction with triphenyl‐phosphane via Staudinger reaction. Hydrolysis with aqueous acetic acid produced in one step 7‐unsubstituted‐amino‐pyrido[2,3‐d]pyrimidine‐2,4‐diones 12 . In a similar amination reaction, 5‐chloropyrido[2,3‐d]pyrimidine‐2,4,7‐triones 13 were aminated and formylated to 5‐alkyl/arylamino‐6‐formyl derivatives 14 ‐ 16 in a combined one‐step‐reaction with bulky arylamines or alkylamines in the presence of dimethylformamide.     

Pyrolysis of cyclo-aromatic diesters

Studies on the pyrolysis of cyclo-aromatic diesters derivatives of 3-phenylprop-2-en-1-ol are presented. The diesters are obtained during catalyzed esterification process of a stoichiometric ratio of 3-phenylprop-2-en-1-ol with suitable cycloaliphatic or aromatic acid anhydride in the solvent-free medium. As an acid anhydrides cyclohexane-1,2-dicarboxylic anhydride, cis-4-cyclohexene-1,2-dicarboxylic anhydride, bicyclo[2.2.1]-5-heptene-2,3-dicarboxylic anhydride, and phthalic anhydride were applied. The thermal properties of obtained compounds under inert atmosphere were tested by means of differential scanning calorimetry and thermogravimetry coupled with FTIR analysis. The pyrolysis products were determined and the probable mechanism of their decomposition was proposed.     

Some transformations of 1-(1,2,3,4-tetrahydronaphthylidene)-malononitrile or cyanoacetate

Summary Syntheses of 11-amino-5,6-dihydronaphtho[1,2:4,5]thieno[2,3-d]pyrimidine (8) and its 10-oxide 7 from 2-amino-1-cyano-4,5-dihydronaphtho[2,1-b]thiophene and its derivatives are described. Several open chain tetrahydronaphthylidene derivatives and a substituted pyrimidine derivative9 were also prepared.Dedicated to Professor Dr. K. Gewald on the occasion of his 60th birthday     

Mass spectra of imidazo[2,1-b]thiazole and thiazolo[3,2-f]xanthene derivatives

The general principles of the mass-spectrometric disintegration of imidazo [2,1-b]thiazole and thiazolo[3,2-f]xanthene derivatives were established, and the characteristic fragments were identified. Disintegration proceeding with cleavage of the bonds in the thiazole ring of the 2(3)-ring system is characteristic of all of the investigated compounds. The cleavage of the S-C bonds, which are the weakest in the investigated systems, proceeds especially readily. Intense peaks of ions due to stepwise disintegration of the pyrimidine ring are also observed in the spectra of thiazoloxanthenes.