Synthesis of substituted disulfonyl-containing polycyclic azines with the bridgehead nitrogen atom. Effects of the structure of 3-substituted pyridinium ylides on the regioselectivity of their reactions with <Emphasis Type="Italic">E</Emphasis>-1,2-di(alkylsulfonyl)-1,2-dichloroethenes

Heating the substituted pyridinium and isoquinolinium salts with E-1,2-di(alkylsulfonyl)-1,2-dichloroethenes in either chloroform or acetone in the presence of three-fold excess of Et₃N gave high yields of substituted 1,2-di(alkylsulfonyl)indolizines and 1,2-di(alkylsulfonyl) pyrrolo[2,1-a]isoquinolines, respectively. Effects of the structure of 3-substituted pyridinium ylides on the regioselectivity of their reaction with E-1,2-di(alkylsulfonyl)-1,2-dichloroethenes were revealed. It was shown that the presence of electron-releasing and electron-withdrawing substituents in the pyridinium ylide favors the formation of 8-substituted and 6-substituted 1,2-(dialkylsulfonyl)indolizines, respectively.     

Investigation of the reaction between sodium hydroxide and syn-and anti-isomers of 5-substituted 2-(4-chlorobutyryl)-aminobenzophenones oximes

By the reaction of syn-isomers of 5-substituted 2-(4-chlorobutyryl)aminobenzophenones oximes with NaOH syn-isomers of 5-substituted 2-(2-oxopyrrolidin-1-yl)benzophenones oximes were obtained. Similarly the anti-isomers of 5-substituted 2-(4-chlorobutyryl)aminobenzophenones oximes treated with NaOH underwent cyclization into anti-isomers of 5-substituted 2-(2-oxopyrrolidin-1-yl)benzophenones oximes. Crystal and molecular structures were investigated of the syn-isomer of 5-methyl-2-(2-oxopyrrolidin-1-yl)benzophenone oxime, the anti-isomer of 5-bromo-2-(2-oxopyrrolidin-1-yl)benzophenone oxime, and the syn-isomer of 5-methyl-2-(4-chlorobutyryl)aminobenzo-phenone oxime. The fragmentation features under the electron impact of syn-and anti-isomers of 5-substituted 2-(2-oxopyrrolidin-1-yl)benzophenones oximes are discussed.     

Dicarba-closo-dodecaborane(12) derivatives of phosphonium salts: easy formation of nido-carborane phosphonium zwitterions

The first examples of arylphosphonium salts containing a dicarba-closo-dodecaborane(12) (closo-carborane) are reported; in contrast to the 1,12-carborane derivative, the 1,2- and 1,7-isomers undergo a facile deboronation reaction in polar solvents to afford the corresponding nido-carborane phosphonium zwitterions.     

Nucleophilic addition to 3-substituted pyridinium salts: expedient syntheses of (-)-L-733,061 and (-)-CP-99,994

[reaction: see text] The addition of nucleophiles to 3-substituted pyridinium salts prepared from N-methylbenzamide and various pyridines has been investigated. Good to excellent regioselectivities favoring the 2,3-disubstituted 1,2-dihydropyridines were observed. The resulting 1,2-dihydropyridines led to the corresponding 2,3-disubstituted pyridines upon treatment with Mn(OAc)3/NaIO4. This methodology was also successfully applied to the enantioselective syntheses of (-)-L-733,061 and (-)-CP-99,994, two members of a new class of highly potent, nonpeptide, Substance P antagonists.     

Pyrazoles by dealkylation of pyrazolium salts

A rapid, convenient conversion of 1,2-dimethylpyrazolium salts ( 1 ) to 1-methylpyrazoles ( 2 ) is accomplished in piperidine or 3-methylpiperidine at temperatures ≥ 106°. This demethylation represents a particularly useful procedure for the synthesis of 3- and 5-substituted aminopyrazoles, which are not readily obtainable by other methods. The 50:50 mixture of piperidinopyrazole isomers 2b can be obtained directly by treating 3-chloro-1,2-dimethyl-5-phenylpyrazolium iodide (3b ) with piperidine in ethanol at 106°.     

Synthesis of 4-and 5-substituted 2-methyl-and 2-(2-carboxyethyl)-1,2,4-triazino-[2,3-a]benzimidazol-4(5)H-3-ones

Condensation of 2-alkylamino-1-aminobenzimidazoles and quaternary 1,2-diamino-3R-benzimidazolium salts with pyruvate and α-ketoglutaric acid has given 4-and 5-substituted 2-methyl-and 2-(2-carboxyethyl)-1,2,4-triazino[2,3-a]benzimidazol-4(5)H-3-ones. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 738–747, May, 2006.     

Macrocycles with 1,2-dicyano-1,2-dithioethene units

Abstract

The new unsaturated macrocyclic tetrathioethers (Z,Z)-4 (n = 0), (Z,Z)-5 (n = 1), (Z,Z)-6 (n = 2) and (Z,Z)-7 (n = 3) were synthesized by the cyclization of (Z)-disodium-1,2-dicyanoethene-1,2-dithiolate (Z)-3 with ω,ω'-dibromoalkanes BrCH₂CH₂(CH₂)nCH₂Br (n = 0;1;2;3) on refluxing in dioxane in yields up to 15%. By reaction of the dithiolate (Z)-3 with 1,3-dibromopropane the unsaturated hexathioether (Z,Z,Z)-6 was also obtained. By the cyclization of dithiolate (Z)-3 with 1,5-dibromopentane and 1,6-dibromohexane the (Z,E)- and (E,E)-isomers, respectively, were formed in addition to the (Z,Z)-isomers. The (E,E)- and (Z,E)-isomers are photochemically convertable to the corresponding themodynamically more stable (Z,Z)-isomers by irradiation with UV-light. The (E,E)-isomers can be synthesized in a straightforward manner using the (E)-disodium-1,2-dicyanoethene-1,2-dithiolate (E)-3. Crystal structures of (Z,Z)-5, (Z,Z)-6, (E,E)-6, (Z,E)-7 and (E,E)-7 are reported.     

A novel synthesis of quinolinium salts via benzotriazole methodology

A novel method for the synthesis of 1,4- and 1,3,4-substituted quinolinium salts and 1,2,4- and 1,2,3,4-substituted-1,2-dibydroquinolines from N-substituted-N(benzotriazol-1-ylmethyl)aniline derivatives is reported.     

<Emphasis Type="Italic">N</Emphasis>-(3-Phosphonopropyl)-substituted α-amino acids and their phosphine oxide analogs

A facile method was developed for the synthesis of N-(3-phosphonopropyl)-substituted α-amino acids and their phosphine oxide analogs based on hydrolysis of 2-oxo-1,2-azaphospholanes and 1,2-azaphospholanium salts prepared from readily available reagents. A chelate Cu^II N-[(3-diphenylphosphoryl)propyl]glycinate was isolated. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2551–2556, November, 2005.     

1,2-Dihydroisoquinolines—XXI: Vinylogous meerwein salts

Treatment of 4-acyl-1,2-dihydroisoquinolines with the Meerwein reagent (triethyloxonium tetrafluoroborate) produces vinylogues of the ethoxyimminium cations in high yield. With a view to developing syntheses of 3-substituted isoquinoline derivatives, some reactions of these salts with nucleophilic reagents have been examined.     

Synthesis and characterization of new derivatives of bis(1,4-diazepinium) salts and bis(γ-substituted pentamethine cyanine(dyes using vinamidinium salt

The preparation of several bis(1,4-diazepinium) salts from the reaction of three 1,2-diamines with a bis(vinamidinium) salt is described. Bis(γ-substituted pentamethine cyanine(dyes are also prepared from the reaction of vinamidinium salt with 1,2-dimethylquinolinium perchlorate and 1,2,3,3-tetramethyl-3H-indolium perchlorate. Data from elemental analyzes, IR, ¹H-NMR, ¹³C-NMR, and mass spectra (MS) confirm the molecular structure of the obtained products.     

Synthesis, chemical properties and mutagenicity of 1,6- and 3,6-dinitrobenzo[a]pyrenes

Nitration of benzo[a]pyrene (BaP) with HNO3 (d = 1.38) produced a mixture of dinitroBaPs (1,6- and 3,6-isomers) and mononitroBaPs (1-, 3- and 6-isomers). Pure 1,6-dinitroBaP and 3,6-dinitroBaP were obtained by the reduction of the dinitroBaPs mixture with NaSH to yield the separable products 1-amino-6-nitroBaP and 3-amino-6-nitroBaP, followed by conversion to dinitroBaPs via the the diazonium salts. The half-wave potentials (E1/2) corresponding to the one-electron reduction of dinitroBaPs were measured and the relationship of these values to the mutagenicity is discussed.     

Reactions of <Emphasis Type="Italic">Z</Emphasis>-isomers of alkylaromatic 1,2-hydroxylamino oximes with methyl-and arylglyoxals

Reactions of the Z-isomers of alkylaromatic 1,2-hydroxylamino oximes (that contain the hydroxylamino group at the primary or secondary carbon atom) with methylglyoxal gave 6-acetyl-5,6-dihydro-4H-1,2,5-oxadiazines. Analogous reactions with arylglyoxals in the presence of trifluoroacetic acid afforded 6-aroyl-5,6-dihydro-4H-1,2,5-oxadiazines. It was found that phenylglyoxal in the absence of the acid yielded N-substituted α-aroylnitrone which undergoes cyclization into the corresponding oxadiazine under the action of CF₃COOH. Dedicated to the memory of Academician N. N. Vorozhtsov on the 100th anniversary of his birth. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1146–1149, June, 2007.     

Heteroaromatic annulation of 2-methyl/2-cyanomethylbenzimidazole dianions with alpha-oxoketene dithioacetals: a highly regioselective synthetic protocol for 1,2- and 2,3-substituted/annulated pyrido[1,2-a]benzimidazoles

A highly efficient and regioselective annulation protocol for a series of linearly 2,3- and angularly 1,2-substituted and annulated pyrido[1,2-a]benzimidazoles involving [3 + 3] cyclocondensation of the dianions generated from 2-methyl (2A) and 2-cyanomethyl (3A) benzimidazoles with a variety of alpha-oxoketene dithioacetals has been reported. Thus the dianion 2A derived from 2-methylbenzimidazole has been shown to undergo regioselective 1,2-addition with various alpha-oxoketene dithioacetals derived from acyclic (4a-d) and cyclic ketones (13a,b, 20, 29 and 32) to afford various carbinol acetals which on intramolecular cyclocondensation in the presence of phosphoric acid furnish the corresponding 1-methylthio-2,3-substituted (5a-c) and 2,3-fused linear polycyclic (14a,b,21, 30, and 33) pyrido[1,2-a]benzimidazoles in high yields. Similarly the dianion 3A from 2-cyanomethylbenzimidazole undergoes one-pot conjugate addition-elimination and cyclocondensation with these alpha-oxoketene dithioacetals to give 4-cyano-3-(methylthio)-1(or 1,2-)-substituted (6a-d) and the corresponding angularly 1,2-fused (16a,b, 23, 31, and 34) polycylic analogues of pyrido[1,2-a]benzimidazoles in excellent yields.     

Effect of substituents in the propynyl fragment and at the nitrogen atom on the intramolecular cyclization of (3-aryl-2-propynyl)-(4-hydroxy- 2-butynyl)ammonium chlorides and also on the recyclization of the products formed

Cyclization of dialkyl(4-hydroxy-2-butynyl)[3-(α-naphthyl)-2-propynyl]ammonium chlorides using aqueous KOH solution occurs under more rigorous conditions (1:1 ratio of salt to base) than in the case of their 3-phenyl(p-chlorophenyl, alkenyl)-substituted analogs (5:1 ratio of salt to KOH). Similarly, more rigorous conditions are also needed for the cyclization of (4-hydroxy-2-butynyl)-(3-phenyl-2-propynyl)piperazinium- and dicyclohexylammonium chlorides. In addition to the cyclization products - corresponding dialkyl(7-hydroxymethyl)naphtho[1,2-f]isoindolinium or dialkyl-(4-hydroxy-methyl)benzo[f]isoindolinium chlorides, the products of recyclization of these – dialkyl-amino-phenanthro[1,2-c]furan or dialkylaminonaphtho[1,2-c]furan are also formed. The indicated derivatives become the main products of conversion of the starting salts by a change of salt to KOH ratio, 1:2, and with an increase in the time of the reaction. The results obtained can be explained by steric effect and also the lower thermal stability of the obtained naphtho[1,2-f]isoindolinium salt system compared to the analogous benzo[f]isoindolinium systems.     

2-Imidazolines. IV . 1-Aryl-2-alkylthio-4,5- diamino-4,5-dihydroimidazoles. Synthesis and properties

1,2-Diimmonium salts ( 1 ) react with S-substituted isothioureas ( 3 ) yielding 2-alkylthio-4,5-diamino-4,5-dihydroimidazoles ( 4 ), which under mild pyrolytic conditions afforded 2-alkylthio-5-aminoimidazoles ( 7 ). Imidazolines ( 4 ) and imidazoles ( 7 ) were easily desulfurated with Raney nickel affording 4,5-diamino-4,5-dihydroimidazole ( 9 ) and 5-aminoimidazole ( 10 ), respectively.     

Synthesis of new derivatives of 1,5,9,13-tetraaza[16]annulene using 2-substituted vinamidinium salts

New 7,15-dibromo-, 7,15-di(bromomethyl)-, and 7,15-di[4-(bromomethyl)phenyl]-1,5,9,13-tetraaza[16]annulene derivatives are synthesized via the condensation reaction of 2-substituted vinamidinium salts [2-substituted 3-(dimethylamino)-N,N-dimethyl-2-propen-1-aminium salts] with 1,8-diaminonaphthalene in acetonitrile/acetic acid. The ultraviolet spectral behavior of these compounds is examined in DMSO.     

Heterocyclic analogs of pleiadiene

1-Substituted and 1,2-disubstituted perimidines and their quaternary salts react with organometallic compounds to give almost exclusively products of addition to the C=N bond. The latter are readily oxidized by chloranil or manganese dioxide to the corresponding 2-substituted perimidines. Metallation (8%) in the 2 position occurs only in the reaction of n-butyllithium with 1-methylperimidine. 1-Methyl-2-chloroperimidine reacts with organolithium compounds to give mainly 2-substituted perimidines.     

Reaction Pathways upon Interaction of Allenic Phosphonates with Selenyl Chlorides

Abstract

Studies were performed on the reaction between alkyl- and arylselenyl chlorides with esters of allenic phosphonic acids, variously substituted at their terminal C-atom. With the esters of the C-3 diasubstituted acids the reaction is highly regioselective and only oxaphosphol heterocyclization occurs to 2,5-dihydro-1,2-oxaphosphols 21-e. With the esters of the propadiene phosphonic acid the reaction is regio- and (Z)-stereoselective: only the 2,3-adducts 3a-b are formed, where the (Z)-isomer and the allenic phosphonates 4a-b are prevalent, as a result of 1,3-sigmatropic isomerization of 3a-b. With the esters of the C-3 monosubstituted acids, complex reaction mixtures are formed. From them were isolated: (E)- and (Z)-isomers of 2,5-dihydro-1,2-oxaphosphols 2f-j; (E)-and (Z)-isomers of the 2,3-adducts 3c-h; (E)-and (Z)-isomers of 4c-f; and (E)-and (Z)-isomers of the 1,2-adducts 5a-d. The reaction partially loses its regioselectivity, but the (Z)-stereoselectivity is preserved:     

Alkylation of dihydrofullerenes

The fulleride dianions C(60)(2-) and C(70)(2-) were generated by deprotonation of the corresponding hydrogenated fullerenes, 1,2-C(60)H(2) and 1,2-C(70)H(2). These anions were prepared in the presence of a variety of alkylating agents, and mono- or dialkylated products were obtained. Alkylation was not successful with sulfonate ester alkylating agents. Deprotonation of monoalkylated compounds, followed by second alkylation with a different alkylating agent, produced heterodialkylated compounds. The monoalkyated material was invariably the 1,2-isomers, while the dialkylated materials were generally 1,4-isomers, although some 1,2-isomer was observed in the C(70) context. The major product from alkylation of C(70)(2-) was the 7,23-isomer 13a, a structure where the alkylation took place near the equator of the fullerene cage, rather than at the more strained carbons near the poles.