Functionalization of 4,6-dinitro-2-phenylindole at position 7

Transformation of the amino group in 7-amino-1-methyl-4,6-dinitro-2-phenylindole afforded a number of new 7-R-4,6-dinitroindoles and a first representative of a novel tricyclic heteroaromatic system of [1,2,5]oxadiazolo[4,3-g]indole. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1508–1511, July, 2008.     

Spectral characteristics and structures of metal complexes with 3-Hydroxy-4,6-dinitro-2-ethoxypyridine: Crystal and molecular structures of di(3-hydroxy-4,6-dinitro-2-ethoxypyridinato)diaquacopper(II)

Seven complexes of manganese(II), copper(II), cadmium, silver(I), samarium(III), and praseodymium( III) with 3-hydroxy-4,6-dinitro-2-ethoxypyridine (HL) were isolated in the crystalline state and studied by IR and UV spectroscopy. The molecular and crystal structures of di(3-hydroxy-4,6-dinitro-2-ethoxypyridinato) diaquacopper(II) [CuL₂(H₂O)₂] were determined. The coordination mode of the organic ligand L^? is bidentate chelating through the O(2) oxygen atoms of the hydroxy group and the O(1) atom of the ethoxy group. The coordination polyhedron of the copper atom is a prolate tetragonal bipyramid (4 + 2) with two O(1) atoms in the axial positions (Cu-O(1) 2.413 Å) and two O(2) atoms of the two L^?ligands and the O(7) atoms of the water molecules in the equatorial plane (Cu-O(2), 1.912 Å; Cu-O(7), 1.972 Å).     

Carbenoid reactions of 2-halomethyl-4,6-dimethyl-s-triazines

Reactions of lithium, sodium, and potassium salts of 2,4,6-trimethyl-s-triazine (1) with 2-halomethyl-4,6-dimethyl-s-triazine (2) (X = Cl, Br) in glyme have been studied and found to give 1,2-bis(4,6-dimethyl-s-triazin-2-yl)ethane (3), 1,2-bis(4,6-dimethyl-s-triazin-2-yl)ethene (5), 1,2,3-tris(4,6-dimethyl-s-triazin-2-yl)cyclopropane (6), 1,2,3-tris(4,6-dimethyl-s-triazin-2-yl)propane (7), and 1,2,3,4-tetrakis(4,6-dimethyl-s-triazin-2-yl)butane (8). It is proposed that product 3 is formed primarily via an S(N)2 reaction, whereas the remaining products are formed primarily via carbenoid reactions that are enumerated.     

Synthesis of 3-substituted 1-aryl-4,6-dinitro-1H-indazoles based on picrylacetaldehyde and their behavior in nucleophilic substitution reactions

A method for the synthesis of 1-aryl-3-formyl-4,6-dinitro-1H-indazoles by the reaction of picrylacetaldehyde with aryldiazonium salts followed by intramolecular cyclization of the resulting picrylglyoxal monoarylhydrazones was developed. Various 4,6-dinitro-1-phenyl-1H-indazoles substituted in position 3 were prepared via transformations involving the formyl group of 3-formyl-4,6-dinitro-1-phenyl-1H-indazole. 3-R-4,6-Dinitro-1-phenyl-1H-indazoles (R = CHO, CN, 1,3-dioxolan-2-yl) react regiospecifically with anionic O-, S-, and N-nucleophiles, in particular, with replacement of only the 4-NO₂ group. Thus previously unknown 3-R-4-Nu-6-nitro-1-phenyl-1H-indazoles were synthesized (Nu is a nucleophile residue).     

Synthesis of 4,6-dinitro-2-trihalogenomethyl-2,3-dihydrobenzo[b]furans

A method for the synthesis of previously unknown 4,6-dinitro-2-trihalogenomethyl-2,3-dihydrobenzo[b]furans has been elaborated. The method is based on condensation of 2,4,6-trinitrotoluene with fluoral or chloral in the presence of K₂CO₃ with subsequent intramolecular cyclization of the resulting 2-picryl-1-(trihalogenomethyl)ethanols. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 569–570, March, 2000.     

Regiospecificity of nucleophilic substitution in 4,6-dinitro-1-phenyl-1H-indazole

The reactions of 4,6-dinitro-1-phenyl-1H-indazole with anionic nucleophiles RS^– and N₃ ^– lead to the regiospecific replacement of the nitro group at position 4. The reaction with N₂H₄·H₂O + FeCl₃ also results in reduction of only the 4-NO₂ group. Based on this fact, a procedure was developed for the preparation of previously unknown 3-unsubstituted 4-X-6-nitro-1-phenyl-1H-indazoles (X is a residue of a nucleophile or NH₂). Comparison of the data on the selective nucleophilic substitution (4-NO₂ group) in 3-Z-1-aryl-4,6-dinitro-1H-indazoles shows that in the case of Z = H, the regiospecificity of substitution is determined by the electronic effect of the annelated pyrazole ring.     

Organocatalytic approach to 3,5,6-trisubstituted and 4,6-disubstituted tetrahydropyran-2-ones

The diarylprolinol ether-catalyzed Michael addition and subsequent cyclization of ethyl 3-methyl-2-oxobut-3-enoate with aldehydes, and γ-substituted β,γ-unsaturated-α-ketoesters with acetaldehyde, afforded the corresponding lactals, which were subjected to oxidation and stereocontrolled hydrogenation to provide 3,5,6-trisubstituted and 4,6-disubstituted tetrahydropyran-2-ones with excellent enantioselectivities.     

Synthesis of peri-annelated heterocyclic systems based on 3-substituted 1-aryl-4,6-dinitro-1H-indazoles

A method for the synthesis of peri-annelated trinuclear heterocycles, including 14-electron heteroaromatic systems, namely, 1H-thiopyrano[4,3,2-cd]indazoles and 1,5-dihydropyrazolo[3,4,5-de]cinnolines, from 3-R-1-aryl-4,6-dinitro-1H-indazoles was developed. The method is based on the high mobility of the NO₂ group in position 4 and consists of either selective nucleophilic substitution of the 4-NO₂ group on treatment with the HSCH₂CO₂Me—K₂CO₃ system followed by intramolecular cyclization of the resulting sulfide (R = CHO) or the corresponding sulfone (R = CN) formed upon its oxidation or direct intramolecular substitution of the 4-NO₂ group (R = CH=NNHPh).     

Some Specific Features of Acid Nitration of 2-Substituted 4,6-Dihydroxypyrimidines. Nucleophilic Cleavage of the Nitration Products

The nitration of 2-substituted 4,6-dihydroxypyrimidines in concentrated sulfuric acid yields the corresponding 5,5-dinitro derivatives. When the substituent in position 2 is an alkyl group, the nitration occurs both at position 5 and at the -carbon atom of the side chain. Hydrolysis of 2-substituted 4,6-dihydroxy-5,5-dinitropyrimidines leads to formation of 1,1-diamino-2-R-2-nitroethylene derivatives. 1,1-Diamino-2,2-dinitro-ethylene was obtained by nitration of 4,6-dihydroxy-2-methylpyrimidine and subsequent hydrolysis of 4,6-dihydroxy-5,5-dinitro-2-(dinitromethylene)-2,5-dihydropyrimidine.     

微波辐射促进选择性合成4,6-二芳基-3,4-二氢嘧啶-2(1H)-酮和嘧啶-2(1H)-酮

探讨了在微波加热条件下,芳香醛、取代苯乙酮和尿素的三组分反应在N,N-二甲基甲酰胺(DMF)中制得4,6-二芳基-3,4-二氢嘧啶-2(1H)-酮类化合物,收率为68%～84%.若在反应体系中加入三甲基氯硅烷,该三组分反应则高产率(66%～87%)地生成相应的脱氢产物4,6-二芳基嘧啶-2(1H)-酮类化合物.该反应具有反应条件温和、产物收率高、操作方便等优点,为4,6-二芳基-嘧啶-2(1H)-酮类药物中间体的合成提供了一条全新的路线.     

Vicarious nucleophilic amination of five-membered 4,6-dinitrobenzoheterocycles

Russian Chemical Bulletin - Reactions of isomeric 4,6-dinitro-1- and 4,6-dinitro-2-phenylindazoles, as well as 4,6-dinitro-2-phenylbenzo[b]furan, with various aminating agents were studied under...     

2-Aryl-3,5-dinitro-1,2-dihydropyridines

The reaction of -nitroacetaldehyde with paraformaldehyde or aromatic aldehydes and ammonium acetate in acetic acid yielded 2-aryl-3,5-dinitro-1,2-dihydropyridines. Aromatic aldehydes, in an ethanol and acetic acid mixture, gave isomeric 3,5-dinitro-1,4-dihydropyridines in addition to 1,2-dihydropyridines. Physicochemical properties and reactivities of the compounds have been studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 64–70, January, 1993.     

New, simple and versatile synthesis of 4,6-disubstituted pyridazin-3(2H)-ones

A simple, two-step synthesis of 4,6-disubstituted pyridazin-3(2H)-ones starting from 2-diethoxyphosphoryl-4-oxoalkanoates and hydrazines is described. The intermediate 4-diethoxyphosphoryl-4,5-dihydropyridazin-3(2H)-ones obtained in this way are used in a Horner-Wadsworth-Emmons olefination of aldehydes to give a variety of disubstituted pyridazin-3(2H)-ones.     

The interaction of disodium salt of 4,6-dinitro-1-oxobenzo-[6,5-c]-2,1,3-oxadiazolediol-5,7 with NaOH and HCl

Disodium salt of 4,6-dinitro-1-oxobenzo-[6,5-c]-2,1,3-oxadiazolediol-5,7 (I) was synthesized. The experimental dependences of the formation function on the solution pH were obtained by the potentiometric titration method for the reaction of NaOH and HCl with I, and the equilibrium constants for the above reactions were calculated. The reaction of I with HCl gives the acid sodium salt of 4,6-dinitro-1-oxobenzo-[6,5-c]-2,1,3-oxadiazolediol-5,7, which is the coordination compound with the Na⁺ cation. The title compound was studied by X-ray diffraction.     

Synthesis of 4,6-dinitro-3-R-benzo[d]isoxazoles and their transformations under the action of nucleophiles

A new procedure was developed for the preparation of 4,6-dinitro-3-R-benzo[d]isoxazoles (R are derivatives of the aldehyde group) based on 2,4,6-trinitrophenylacetaldehyde. The resulting compounds are characterized by the regiospecific substitution of the nitro group at position 4 under the action of anionic nucleophiles RS^–, RO^–, F^–, or N₃ ^–, which allowed the development of a new method for the preparation of previously unknown 4-Nu-6-nitro-3-R-benzo[d]isoxazoles (Nu is the residue of a nucleophile). At the same time, oxidative nucleophilic substitution under the action of anions of some -dicarbonyl compounds leads to the replacement of the hydrogen atom at position 7 with the corresponding C-nucleophiles.     

Synthesis and thermal rearrangement of 2-(2-chloroethoxy)-4,6-disubstituted <Emphasis Type="Italic">sym</Emphasis>-triazines

On thermolysis of 4-methoxy- and 4-alkylamino-2-(2-chloroethoxy)-6-morpholino(piperidino)-sym-triazines, the corresponding oxazolo- or imidazo-sym-triazinones are formed by elimination of methyl chloride or hydrogen chloride, and 4,6-disubstituted 3-(2-chloroethyl)-sym-triazin-2-ones are formed from 4,6-dimorpholino(dipiperidino) derivatives.     

Synthesis and Structure of Derivatives of 9-(2-Oxopropyl)-1,5-dinitro-7,8-benzo-3-azabicylo[3.3.1]non-7-en-6-ones

A number of 3-R-9-(2-oxopropyl)-1,5-dinitro-7,8-benzo-3-azsbicyclo[3.3.1]non-7-en-6-ones was synthesized by Mannich reaction involving Yanovsky adduct of 2,4-dinitronaphthol. It was established by molecular spectroscopy and X-ray diffraction analysis that the piperidine ring in these compounds was in the chairconformation with a diequatorial position of the substituent attached to the heteroatom and 2-oxo-propyl group, and the cyclohexenone fragment was in sofaform. By an example of 3-methyl-9-(2-oxopropyl)-1,5-dinitro-7,8-benzo-3-azsbicyclo[3.3.1]non-7-en-6-one the dissociative ionization of bicyclononanes under the electron impact was investigated.     

Reaction of some coumarin and 4,6-diaryl-2H-pyran derivatives with secondary amines

The reaction of piperidine, morpholine, piperazine or dimethylamine with several coumarins, 3-bromocoumarin, 4,6-diaryl-2H-pyran-2-ones and 3-bromo-4,6-diaryl-2H-thiopyran-2-ones gave o-hydroxycinnamic acid amides, benzofurans, open-chain δ-oxoamides and thiophene derivatives, respectively.     

Heterocyclic nitro compounds. 26. Reaction of 1-substituted 3,5-dinitro-1,2,4-triazoles with anions of heterocyclic NH acids

1-Substituted 3-nitro-5-(N-azolyl)-1,2,4-triazoles mixed with 1-substituted 3-nitro-1,2,4-triazol-5-ones are obtained in the reaction of 1-substituted 3,5-dinitro-1,2,4-triazoles with anions of heterocyclic NH acids (1,2,4-triazole, 1,2,3-triazole, pyrazole, benzotriazole, benzimidazole, and indazole derivatives). 1-Methyl-3-nitro-5-amino-1,2,4-triazole is formed instead of the expected 5-tetrazolyl derivative in the reaction of 1-methyl-3,5-dinitro-1,2,4-triazole with tetrazole in alkaline media. See [1] for communication 25. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 257–261, February, 1980.     

1-烷基-4,6-二芳基四氢三嗪硫酮化合物的合成及其氧化反应

三芳基缩二胺与烷基硫脲在二氧六环回流条件下反应, 可生成1-烷基-4,6-二芳基四氢三嗪硫酮化合物3。利用芳香醛, 烷基硫脲和醋酸铵一锅法也能得到3, 而三芳基缩二胺与芳基硫脲反应, 则生成了咪唑啉的硫氰酸盐。室温下,在相转移催化剂TEBA存在时, 3可被高锰酸钾氧化, 得到1-烷基-4,6-二芳基-2(1H)三嗪酮化合物。