Azaindole derivatives

The reaction of 2,4-dichloro-5-(-chloroethyl)pyridine with ammonia and N-ethylaniline, leading to the formation of 5-azaindoline derivatives, has been studied. The processes of the formation of 6-phenylamino and 6-(N-alkyl-N-phenylamino) derivatives of 7-azaindoline, 5-azaindoline, and 5,7-diazaindoline taking place with N-dealkylation and without it have been compared.For part XXVI, see [16].     

Azaindole derivatives

On the basis of a comparative study of the influence of various factors (ratio of the reactants, temperature, reaction time, polarity of the medium, and the catalytic action of metals) on the reaction of 2,6-dichloro-3-(-chloroethyl)-4-methylpyridine (trichlorocollidine) with 2,6-dimethylamine, it has been shown that, in addition to 6-chloro-1,4-dimethyl-7-azaindoline, the process gives rise to various amounts, depending on the conditions of its performance, of other products: 3-(-dimethylaminoethyl)-2,6-dichloro-4-methylpyridine, 2-chloro-3-(-chloroethyl)-6-dimethylamino-4-methylpyridine, 2-chloro-6-dimethylamino-3-(-dimethylaminoethyl)-4-methylpyridine, and 6-dimethylamino-1,4-dimethyl-7-azaindoline. The best method for directing the process to the formation of azaindoline derivatives is the use of highly polar solvents.For Communication XXXIII, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 8, pp. 1122–1126, August, 1970.     

Introduction of substituents in the pyridine proton of 7-azaindoline

Electropilic substitution (nitration, bromination, and chlorination) of 4-methyl-6-chloro-7-azaindoline (and its N-acetyl derivative) takes place in the 5 position. 4-Methyl-5-amino-7-azaindoline, 4-methyl-5-nitro-7-azaindoline, and 1-acetyl-4-methyl-5-amino-6-chloro-7-azaindoline were obtained by reduction of 1-acetyl-4-methyl-5-nitro-6-chloro-7-azaindoline under various conditions. A method was developed for the preparation of a new three-ring system — 1,2,3-oxadiazolo[5,4-b]-pyrrolo[2,3-e]pyridine.Communication L from the series Derivatives of Azaindoles. See [1] for communication XLIX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 380–384, March, 1977.     

7-Azaindole derivatives

A study is made of new synthetic routes, based on accessible 3-formyl-7-azaindoles, to 3-substituted 7-azaindole. 2-Phenyl-4-(1-phenyl-4-methyl-7-azaindolyl-3-rnethylene)-1, 3-oxazol-5-one is synthesized, and it is converted to 1-phenyl-4-methyl-7-azatryptophane, 1-phenyl-4-methyl-7-azaindolyl-3-acetic acid,1-phenyl-3-(,-dihydroxypropyl)-4-methyl-7-azaindole, and 1-phenyl-4-methyl-7-azaindolyl-3-pyrotartaric acid.For Part XVIII see [1].     

Azaindole derivatives

An increase in the C-N bond strength in a series of N-alkyl substituents (methyl < ethyl < hexyl < butyl) was established from a study of N-dealkylation processes during the synthesis of substituted 7-azaindoles from 2,6-dichloro-3-(-chloroethyl)-4-methylpyridine and unsymmetrical alkylbutylamines.See [1] for Communication XXXV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1546–1549, November, 1970.     

Azaindole derivatives. 66. 1,6-disubstituted 4-methyl-5-cyano-7-azaindolines

A general method was developed for the synthesis of 1,6-disubstituted 4-methyl-5-cyano-7-azalndolines from the readily available ammonium salt of 2,6-dihydroxy-3-(-hydroxyethyl)-4-methyl-5-cyanopyridine through the corresponding N-substituted ammonium salts and N-substituted 2-amino-3-(-hydroxyethyl)-4-methyl-5-cyano-6-hydroxypyridines with treatment of the latter by POCl₃. This method gives a 40% yield of 4-methyl-5-cyano-7-azaindoline compounds containing various aralkyl or alkyl substituents at N-1 and a hydroxy group or halogen atom at C-6 in three steps.For Communication 65, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 84–88, January, 1985.     

Derivatives of azaindoles. 65. Synthesis of 1-benzyl-4-methyl-5-cyano-6-hydroxy-7-azaindoline

Treatment of the ammonium (I) or benzylammonium salt of 2,6-dihydroxy-3-(-hydroxyethyl)-4-methyl-5-cyanopyridine (II) with a mixture of benzylamine and phosphorus pentoxide yielded 2-benzylamino-3-(-hydroxyethyl)-4-methyl-5-cyano-6-hydroxypyri-dine (III), which, when heated with phosphorus oxychloride, is converted to 1-benzyl-4-methyl-5-cyano-6-hydroxy-7-azaindoline (IV). The products of thermal fragmentation of II with benzylamine were studied by the method of chromato-mass spectrometry. In addition to compound III, N,N-dibenzylurea (V) and the dibenzylamide of malonic acid (VI) were preparatively isolated from the reaction products. The cyclization of I and II to 4-methyl-6-hydroxy-2,3-dihydro-7-azabenzofuran (VII) and 4-methyl-5-cyano-6-hydroxy-2,3-dihydro-7-azabenzofuran (VIII) was carried out. Heating VIII with benzylamine at 200–210°C led to compound III.For communication 64, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1105–1109, August, 1984.     

Electrochemical Ammonia Gas Sensing in Nonaqueous Systems: A Comparison of Propylene Carbonate with Room Temperature Ionic Liquids

First, the direct and indirect electrochemical oxidation of ammonia has been studied by cyclic voltammetry at glassy carbon electrodes in propylene carbonate. In the case of the indirect oxidation of ammonia, its analytical utility of indirect for ammonia sensing was examined in the range from 10 and 100 ppm by measuring the peak current of new wave resulting from reaction between ammonia and hydroquinone, as function of ammonia concentration, giving a sensitivity 1.29×10^?7 A ppm^?1 (r²=0.999) and limit‐of‐detection 5 ppm ammonia. Further, the direct oxidation of ammonia has been investigated in several room temperature ionic liquids (RTILs), namely 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([C₄mim] [BF₄]), 1‐butyl‐3‐methylimidazolium trifluoromethylsulfonate ([C₄mim] [OTf]), 1‐Ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide ([C₂mim] [NTf₂]), 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide ([C₄mim] [NTf₂]) and 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([C₄mim] [PF₆]) on a 10 μm diameter Pt microdisk electrode. In four of the RTILs studied, the cyclic voltammetric analysis suggests that ammonia is initially oxidized to nitrogen, N₂, and protons, which are transferred to an ammonia molecule, forming NH via the protonation of the anion(s) (A^?). However, in [C₄mim] [PF₆], the protonated anion was formed first, followed by NH . In all five RTILs, both HA and NH are reduced at the electrode surface, forming hydrogen gas, which is then oxidized. The analytical ability of this work has also been explored further, giving a limit‐of‐detection close to 50 ppm in [C₂mim] [NTf₂], [C₄mim] [OTf], [C₄mim] [BF₄], with a sensitivity of ca. 6×10^?7 A ppm^?1 (r²=0.999) for all three ionic liquids, showing that the limit of detection was ca. ten times larger than that in propylene carbonate since ammonia in propylene carbonate might be more soluble in comparison with RTILs when considering the higher viscosity of RTILs.     

Some reactions of 2-chloro-3-(β-chloroethyl)-4,6-dihydroxypyridine

The chemical properties of 2-chloro-3-(-chloroethyl)-4,6-dihydroxypyridine (I) have been studied. It has been shown that this compound, which is relatively stable in acids and in neutral and, particularly, in alkaline media, readily splits off hydrogen chloride under mild conditions and is converted into derivatives of 2, 3-dihydro-5-azabenzofuran. The dehalogenation of I in an acid medium yielded 3-(-chloroethyl)-4, 6-dihydroxypyridine, which was converted into 4, 6-dichloro-3-(-chloroethyl)pyridine and into 6-chloro-4-methoxy-3-vinylpyridine.     

Derivatives of n-(pyrimid-4-yl)ethylamine

In order to find compounds possessing antibacterial activity, a number of new derivatives of N-(pyrimid-4-yl)ethylamine have been synthesized from 5-amino-4, 6-dichloropyrimidine, 2-amino-4, 6-dichloro-pyrimidine, 4, 6-dichloro-2-phenylpyrimidine, and 2,4-dichloro-6-methylpyrimidine and various ethylamines substituted in the -position. Several derivatives of 4-(4-methylpiperazinyl)pyrimidine have also been obtained. Results of a biological study of the compounds obtained are presented.For part II, see ¦1¦.     

Preparation of the isomeric azaindoline family by intramolecular carbolithiation

An operationally convenient, one-pot, three-step sequence has been developed that provides access to 3-substituted 4-, 5-, 6-, and 7-azaindolines (2,3-dihydro-1H-pyrollopyridines) via intramolecular carbolithiation of the aryllithium derived from an appropriate (N,N-diallylamino)bromopyridine. Whereas cyclization proceeds as expected to give 1-allyl-3-methyl-4-azaindoline and 1-allyl-3-methyl-6-azaindoline following protonation of the 3-CH2Li group of the azaindoline, the isomeric 3-methyl-5-azaindoline and 3-methyl-7-azaindoline are generated as 3-methyl-N-allyl anions prior to quench with MeOH.     

Synthesis of some ω- (2,5-dichloro-3-thienyl)alkanoic acids and their intramolecular ring closure

The synthesis of 1-chloro-4,5,6,7-tetrahydrobenzo[c]-4-thiophenone and 1-chloro-5,6,7,8-tetrahydro-4H-cyclohepta[c]-4-thiophenone was accomplished by the cyclization of the acid chlorides of -(2,5-dichloro-3-thienyl)butyric acid and -(2,5-dichloro-3-thienyl)valeric acid, respectively, to 1,3-dichloro-4,5,6,7-tetrahydrobenzo[c]-4-thiophenone and 1,3-dichloro-5,6,7,8-tetrahydro-4H-cyclohepta[c]-4-thiophenone and by partial dehalogenation of the latter by heating with copper metal in propionic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1358–1360, October, 1971.     

Azaindole derivatives

As in the case of N-substituted anilines, trichlorocollidine forms 6-chloro-7-azaindoline derivatives rather than 6-amino-7-azaindoline derivatives with sterically hindered primary amines of the β-phenylisopropylamine type. On passing to tert-butylamine, nucleophilic attack at the α and α′ positions of the pyridine ring proves to be sterically impossible, and dehydrohalogenation of trichlorocollidine to 2,6-dichloro-3-vinyl-4-methylpyridine becomes the principal reaction.     

Reactions of phenylenedioxytrihalophosphoranes with arylacetylenes: VII. Reaction of 2,2,2-trichloro-4-fluoro-1,3,2λ<Superscript>5</Superscript>-benzodioxaphosphole with phenylacetylene

2,2,2-Trichloro-4-fluoro-1,3,2⁵-benzodioxaphosphole reacts with phenylacetylene to give 2,7-dichloro-5-fluoro-4-phenyl-2H-1,2⁵-benzoxaphosphinine 2-oxide. Hydrolysis of the latter leads to opening of the oxaphosphinine ring with formation of (E)-2-(4-chloro-2-fluoro-6-hydroxyphenyl)-2-phenylethenylphosphonic acid.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 12, 2004, pp. 1846–1851.Original Russian Text Copyright © 2004 by Mironov, Shtyrlina, Varaksina, Efremov, Konovalov.     

Kinetics of the simultaneous oxidation of nickel(II) and sulfur(IV) by oxygen in alkaline medium in Ni(II)–sulfur(IV)–O2 system

In the Ni(II)–S(IV)–O₂ system in the region of pH > 8.4, both Ni(II) and S(IV) are simultaneously autoxidized, and when sulfur is consumed fully NiOOH precipitates. At pH > 8.4, ethanol has no effect on the rate, whereas ammonia strongly inhibits the reaction when pH > 7.0. The kinetics of the reaction, in both the presence and the absence of ethanol, is defined by the rate law where k is the rate constant, K_O is the equilibrium constant for the adsorption of O₂ on ? Ni(OH)₂ particle surface. In ammonia buffer, the factor F is defined by where K, K_OH, K₁, K₂, K₃, and K₄ are the stability constants of NiSO₃, NiOH⁺, Ni(NH₃)²⁺, Ni(NH₃), Ni(NH₃), and Ni(NH₃), respectively. In unbuffered medium, the factor F reduces to The values of k and K^sp were found to be (1.3 ± 0.08) × 10^?1 s^?1 and (4.2 ± 3.5) × 10^?16, respectively, at 30°C. A nonradical mechanism that assumes the adsorption of both SO₃^2? and O₂ on the ? Ni(OH)₂ particle surface has been proposed. At pH ≤ 8.2, Ni(II) displays no catalytic activity for sulfur(IV)‐autoxidation and it is also not oxidized to NiOOH. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 464–478, 2010     

SCF and MC–SCF Study of CO2 with bond angle variation

Multiconfiguration (MC ) SCF calculations are reported for CO₂ for bond angles between 60° and 180°. The ground state configuration is found to be …?5a4b∣b∣a for small bending angles and …?6a3b∣b∣a for large bending angles, the change in ground state character occurring at a bond angle of about 100°. The force constant for bending obtained from the MC –SCF function is about 8.0% lower than the corresponding SCF value, and in considerably better agreement with experiment.     

2-Spiroanellated 1,3-Benzodioxoles from the Reaction of 2,3-Dihydro-1 H-pyrrol-3-ones with Tetrachloro-1,2-benzoquinone

Novel spiro[1,3-benzodioxole-2,2-(2,3-dihydro-1H-pyrrol-3-ones)] were obtained from 2-aminomethylene-2,3-dihydropyrrol-3(1H)-ones and tetrachloro-1,2-benzoquinone in ethanol at room temperature. However, in addition, 3,4-dichloro-7-methoxy-5-(4-methoxyphenyl)-5,10-dihydrophenazine-1,2-dione was formed in the reaction of 1-(4-methoxyphenyl)-2-(4-methoxyphenylaminomethylene)-4,5-diphenyl-1,2-dihydropyrrol-3-one with tetrachloro-1,2-benzoquinone.     

Thermal stability of intermediate sized acetylenic compounds and the heats of formation of propargyl radicals

4-Methylhexyne-1, 5-methylhexyne-1, hexyne-1, and 6-methylheptyne-2 have been decomposed in comparative-rate single-pulse shock-tube experiments. Rate expressions for the initial decomposition reactions at 1100°K and from 2 to 6 atm pressure are In combination with previous results, rate expressions for propargyl C? C bond cleavage are related to that for the alkanes by the expression These results yield a propargyl resonance energy of D(nC₃H₇-H) – D(C₃H₃-H) = 36 ± 2 kJ, in excellent agreement with a previous shock-tube study. They also lead to D(CH₃C≡CCH₂-H) – D(C₃H₃-H) = 0.6 ± 3 kJ, D(sC₄H₉-H) – D(iC₃H₇-H) = 0 ± 3 kJ, D(iC₄H₉-H) – D(nC₃H₇-H) = 2 ± 3 kJ, and D(nC₃H₇-H) – D(iC₃H₇-H) = 13.9 ± 3 kJ (all values are for 300°K). The systematics of the molecular decomposition process are explored.     

Pyrrolopyrimidine nucleosides. IV. The synthesis of certain 4,5-disubstituted-7-(β-d-ribofuranosyl)pyrrolo[2,3-d]pyrimidines related to the pyrrolo[2,3-d]pyrimidine nucleoside antibiotics

The treatment of 4-chloro-7-(2′,3′,5′-tri-O-acetyl-β-D-ribofuranosyl)pyrrolo[2,3-d]pyrimidine ( 4 ) with N-bromoacetamide in methylene chloride has furnished the 5-bromo derivative of 4 which on subsequent deacetylation provided a good yield of 5-bromo-4-chloro-7-(β-D-ribo-furanosyl)pyrrolo[2,3-d] pyrimidine ( 6 ). Assignment of the halogen substituent to position 5 was made on the basis of pmr studies. Treatment of 6 with methanolic ammonia afforded 4-amino-5-bromo-7-(β-D-ribofuranosyl)pyrrolo[2,3-d ]pyrimidine ( 8 , 5-bromotubercidin) and a subsequent study has revealed that the 4-chloro group of 6 was replaced preferentially in a series of nucleophilic displacement reactions. The analogous synthesis of 4,5-dichloro-7-(β-D-ribo-furanosyl)pyrrolo[2,3-d]pyrimidine ( 13b ) and 4-chloro-5-iodo-7-(β-D-ribofuranosyl)pyrrolo[2,3-d]pyrimidine ( 13a ) from 4 furnished 5-chlorotubercidin ( 15 ) and 5-iodotubercidin ( 14 ), respectively, on treatment of 13b and 13a with methanolic ammonia. The possible biochemical significance of these tubercidin derivatives is discussed.     

Azaindole derivatives. 67. Synthesis of N-substituted 1-benzyl-4-methyl-5-cyano-6-amino-7-azaindoles

N-substituted 1-benzyl-4-methyl-5-cyano-6-amino-7-azaindoles have been synthesized from the respective 1-benzyl-4-methyl-5-cyano-6-chloro(and 6-hydroxy)-7-azaindoles. The effect of the 5-cyano group on the oxidation-reduction processes accompanying nucleophilic replacement of chlorine in 6-chloro-7-azaindoles by primary and secondary amines has been considered. 7-Azaindoline compounds were dehydrogenated by chloranil to N-substituted 1-benzyl-4-methyl-5-cyano-6-amino-7-azaindoles.For communication 66, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 91–96, January, 1986.