Investigations in the Field of 2,3'-Biquinolyl. 14. Reaction of Dihydro Derivatives of 2,3'-Biquinolyl with Bromine and Iodine

Methods were developed for the synthesis of 6'-bromo- and 6',8'-dibromo-2,3'-biquinolyls and 3',4'-dibromo- and 3',4',6'-tribromo-1'-ethoxycarbonyl-1',2',3',4'-tetrahydro-2,3'-biquinolyls on the basis of the bromination of the dihydro derivatives of 2,3'-biquinolyl. It was shown that the reaction of 1'-alkyl-1',4'-dihydro-2,3'-biquinolyls with bromine and iodine leads to 1'-alkyl-1',2'-dihydro-2,3'-biquinolyl-2'-ones.     

Investigations on 2,3'-Biquinolyls. 15. Regioselectivity of the Addition of Nitromethane Anion to 1'-Alkyl-3'-(2-quinolyl)quinolinium Halides

1'-R-3'-(2-Quinolyl)quinolinium halides react with nitromethane forming products of addition at the position 4', the 1'-R-4'-nitromethyl-1',4'-dihydro-2,3'-biquinolyls. A method has been developed for the synthesis of 1'-phenacyl-1',4'-dihydro-2,3'-biquinolyls based on the alkylation of 1',4'-dihydro-2,3'-biquinolyl with halogen derivatives in DMF.     

Investigations on 2,3'-Biquinolyls. 12. Alkylation and Arylation of 2,3'-Biquinolyl Dianion with Organometallic Compounds. New Type of Reaction for Dianions of Aromatic Compounds

2,3'-Biquinolyl dianion reacts with organolithium and organomagnesium compounds with the formation, after treatment of the reaction mixture with water, of 2'-alkyl(aryl)-1',2'-dihydro-2,3'-biquinolyls, and, after treatment of the reaction mixture with alkyl halides, of 1'-alkyl-2'-alkyl(aryl)-1',2'-dihydro-2,3'-biquinolyls. The reaction includes attack of the nucleophilic reagent with an electron transfer to a molecule of solvent.     

Investigations In the Field of 2,3'-Biquinolyl. 13. Regioselectivity in the Nitration of 2,3'-Biquinolyls and Their 1',4'-Dihydro Derivatives

The nitration of 2,3'-biquinolyls in concentrated sulfuric acid with an equivalent amount of nitric acid at room temperature takes place exclusively at the 2-quinolyl fragment with the formation of the 5- and 8-nitro derivatives or their mixtures. The nitration of the 1',4'-dihydro derivatives under these conditions leads to analogous compounds. Reduction of the nitrobiquinolyls gives the respective amines. Acylation of the latter leads to acylamino-2,3'-biquinolyls.     

The investigation in 2,3'-biquinoline series 26.* Regioselective nitration of 1'-alkyl-1',4'-dihydro-2,3'-biquinolin-4'-ones and 1'-alkyl-1',2'-dihydro-2,3'-biquinolin-2'-ones

The nitration of 1'-alkyl-1',4'-dihydro-2,3'-biquinolin-4'-ones and 1'-alkyl-1',2'-dihydro-2,3'-biquinolin-2'-ones has been investigated. It was shown that the regioselectivity of nitration of the first depends on the acidity of the medium and the order of adding reactants. In strongly acidic medium 1'-alkyl-5,6'-dinitro-1',4'-dihydro-2,3'-biquinolin-4'-ones or mixtures of them with 1'-alkyl-5-nitro-1',4'-dihydro-2,3'-biquinolin-4'-ones are formed. In less acidic media 1'-alkyl-6'-nitro-1',4'-dihydro-2,3'-biquinolin-4'-ones and then 1'-alkyl-6,6'-dinitro-1',4'-dihydro-2,3'-biquinolin-4'-ones are formed. Nitration of 1'-alkyl-1',2'-dihydro-2,3'-biquinolin-2'-ones leads to 1'-alkyl-6'-nitro-1',2'-dihydro-2,3'-biquinolin-2'-one and then 1'-alkyl-6,6',8'-trinitro-1',2'-dihydro-2,3'-biquinolin-2'-one. *For Communication 25 see [1]. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 578-585, April, 2009.     

Condensed Thienopyrimidines. 14. Synthesis of 10H-Thiopyrano[4',3':4',5']thieno[2',3':4,5]pyrimido[2,3-c]-1,2,4-triazines

Reaction of a substituted 2-aminothienothiopyran with methyl(phenyl) isothiocyanate, intramolecular cyclization of the obtained N'-methyl(phenyl) thioureido derivatives, and work up of the cyclization products with hydrazine hydrate gave 2-hydrazinodihydrothiopyranothienopyrimidines. Treatment of the latter with pyruvic acid gave the novel 10H-thiopyrano[4',3':4',5']thieno[2',3':4,5]pyrimido[2,3-c]-1,2,4-triazines.     

Investigations on 2,3′-Biquinolyl. 16. The Regioselectivity of Reduction of 1-Alkyl-3-(2-quinolyl)quinolinium and 1,1′-Dialkyl-3,3′-di(2-quinolyl)-1,1′,4,4′-biquinolyl Iodides Using Metallic Zinc,Lithium and Potassium

The reaction of 1-alkyl-3-(2-quinolyl)quinolinium iodides with excess zinc in THF gives a diastereomeric mixture of 1,1′-dialkyl-3,3′-di(2-quinolyl)-1,1′,4,4′-tetrahydro-4,4′-biquinolyls. An excess of lithium in THF gives a mixture of 1′,2′-dihydro-2,3′-biquinolyl and 1′-alkyl-1′, 4′-dihydro-2,3′-biquinolyl with the former predominating. The reduction by lithium in THF of 1,1′-dialkyl-3,3′-di(2-quinolyl)-1,1′,4,4′-tetrahydro-4,4′-biquinolyls leads to analogous products. Reduction of 1-alkyl-3-(2-quinolyl)quinolinium iodides by metallic potassium gives 1-alkyl-1′,4′-dihydro-2,3′-biquinolyls. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1208–1212, August, 2005.     

Three‐Step Synthesis of 3‐Aryl‐2‐sulfanylthieno[2,3‐b]‐, ‐[2,3‐c]‐, or ‐[3,2‐c]pyridines from the Corresponding Aryl(halopyridinyl)methanones

A convenient three‐step procedure for the synthesis of three types of 3‐aryl‐2‐sulfanylthienopyridines 4, 8 , and 12 has been developed. The first step of the synthesis of thieno[2,3‐b]pyridine derivatives 4 is the replacement of the halo with a (sulfanylmethyl)sulfanyl group in aryl(2‐halopyridin‐3‐yl)methanones 1 by successive treatment with Na₂S?9 H₂O and chloromethyl sulfides to give aryl{2‐[(sulfanylmethyl)sulfanyl]pyridin‐3‐yl}methanones 2 . In the second step, these were treated with LDA (LiNⁱPr₂) to give 3‐aryl‐2,3‐dihydro‐2‐sulfanylthieno[2,3‐b]pyridin‐3‐ols 3 , which were dehydrated in the last step with SOCl₂ in the presence of pyridine to give the desired products. Similarly, thieno[2,3‐c]pyridine and thieno[3,2‐c]pyridine derivatives, 8 and 12 , respectively, can be prepared from aryl(3‐chloropyridin‐4‐yl)methanones 5 and aryl(4‐chloropyridin‐3‐yl)methanones 9 , respectively.     

Synthesis and Properties of 6-Amino-7-hetaryl-5-R-5H-pyrrolo[2,3-b]pyrazine-2,3-dicarbonitriles

We have established that when 5-chloro-6-[cyano(2,3-dihydro-1-R-benzo[d]azol-2-yl)methyl]-2,3-pyrazinedicarbonitriles are reacted with nucleophilic reagents (aliphatic and aromatic amines, hydrogen sulfide), annelation of the five-membered ring occurs on the [b] face of the pyrazine with formation of 6-amino-7-hetaryl-5-R-5H-pyrrolo[2,3-b]pyrazine-2,3-dicarbonitriles and 6-amino-7-(1H-benzo[d]imidazol-2-yl)thieno[2,3-b]pyrazine-2,3-dicarbonitrile respectively. Further heating with excess of acylating reagent leads to formation of a novel heterocyclic system 1H-benzo[4,5]imidazo[1,2-c]pyrazino[2',3':4,5]pyrrolo[3,2-e]pyrimidine. Reaction of vicinal dinitriles with hydrazine hydrate leads to the novel system 1H-pyrrolo[2',3':5,6]pyrazino[2,3-d]pyridazine.     

Synthesis of 2,3-diformyl-5-ethylbenzofuran and its derivatives

A mixture of 3-formyl and 3-acetoxymethyl derivatives is formed in the oxidation of 2-carbethoxy-3-methyl-5-ethylbenzofuran with selenium dioxide. Reduction of the products with lithium aluminum hydride gives the corresponding 2,3-dihydroxymethyl derivatives, which are converted to 2,3-diformyl derivatives by successive oxidation by the Fetizon method and with manganese dioxide. The corresponding benzofuro[2, 3-d]pyridazines were synthesized by reaction of 2-carbethoxy-3-formyl-5-ethylbenzofuran with hydrazine hydrate.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 893–895, July, 1982.     

Synthesis of novel benzo[b]pyrimido[4',5':5,4]thieno[2,3-e][1,6]naphthyridine-8-ones via Pictet–Spengler cyclization

An efficient method for the synthesis of novel benzo[b]pyrimido[4',5':5,4]thieno[2,3e]-[1,6]naphthyridine-8-one derivatives via Pictet–Spengler cyclization is reported. The reaction of 4-(3-aminopyrimido[4,5-d]thieno-2-yl)quinoline-2-ones, which could be obtained from Thorpe–Ziegler isomerization of 4-bromomethylquinoline-2-ones and 5-cyano-1,6-dihydro-4-methyl-2-phenyl-6-thioxopyrimidine,with aromatic aldehydes in the presence of BF_3·OEt_2 gives pyrimidothieno[1,6]naphthyridines in good yields.     

Quinoxaline-2,3(1H,4H)-dithione: Synthesis and reactions

Quinoxaline-2,3(1H,4H)-dithione can be synthesized efficiently through the thionation of quinoxaline-2,3(1H,4H)-dione with phosphorous pentasulfide. It can also be obtained by reaction of 2,3-dichloroquinoxaline with thiourea or sodium hydrogen sulfide. The most common reactions of quinoxaline-2,3(1H,4H)-dithione involve deprotonation and electrophilic attack at the sulfur atoms to give various substituted derivatives and poly-fused heterocyclic ring systems. The current review aims to provide a survey of the developments in quinoxaline-2,3(1H,4H)-dithione chemistry until 2016.     

Synthesis and Properties of Ethyl Esters of 4-Dialkylamino-2-methylthiothieno[2,3-d]pyrimidine-6-carboxylic Acids

The reaction of 4-dialkylamino-6-chloro-2-methylthiopyrimidine-5-carbaldehydes with ethyl mercaptoacetate in the presence of triethylamine gives the corresponding ethyl esters of thieno[2,3-d]pyrimidine-6-carboxylic acids. These esters were subjected to alkaline hydrolysis, hydrazinolysis, and lithium aluminum hydride reduction to give the corresponding acids, hydrazides, and (thieno[2,3-d]pyrimidin-6-yl)methanols.     

Functionalized naphthol[2,3-h] quinoline-7,12-diones

The addition of secondary and primary amines to ethyl (1-amino-9,10-anthraquinon-2-yl)propynoate affords an easily separable mixture of the corresponding ethyl 3-dialkylaminoor 3-alkylamino-3-(1-amino-9,10-anthraquinon-2-yl)acrylate and 3-dialkylamino- or 3-alkylaminonaphthol[2,3-h]quinoline-2(1H), 7,12-trione (in ∼4: 1 ratio). Intramolecular cyclization of the resulting substituted ethyl acrylates results in the formation of 4-dialkylaminoor 4-alkylamino-2-chlorinated pyridine rings. Subsequent nucleophilic substitution of the chlorine atom gives 2-functionalized 4-dialkylamino- or 4-alkylaminonaphtho[2,3-h]quinoline-7,12-diones. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2327–2332, November, 1998.     

Heterocyclic analogs of 5,12-naphthacenequinone. 2. Synthesis of 4,11-dihydroxynaphtho[2,3-f]indazole-5,10-dione and its n-methyl derivatives

On methylating 4,11-dimethoxynaphtho[2,3-f]indazole-5,10-dione with methyl iodide in the presence of base a mixture is formed of its 1-and 2-methyl derivatives. Demethylation of the methoxy groups of the starting material and of the products of its alkylation leads to the formation of 4,11-dihydroxynaphtho[2,3-f]indazole-5,10-dione (pyrazoloquinizarine) and its 1-and 2-methyl derivatives. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 691–696, May, 2006.     

Synthesis and Properties of Substituted Isoxazolo[3',4':4,5]thieno[2,3-b]pyridines

We synthesized derivatives of a novel heterocyclic system, isoxazolo[3',4':4,5]thieno[2,3-b]pyridine by sequential conversions in three steps: isomerization of 2-(2-R-ethylthio-2-oxo)-3-pyridyl cyanides obtained by alkylation from substituted 3-cyano-2(1H)-pyridinethiones by -halomethyl ketones in alkaline medium, to form 3-aminothieno[2,3-b]pyridines; diazotization of the amino group followed by nucleophilic substitution of the diazonium group by an azido group, bypassing the step of isolating the diazonium salts; and thermolysis of the azides formed.     

Investigation of 2,3'-Biquinolyl. 11. Regioselectivity in the Hydroxylation of 1-Alkyl-3-(2-quinolyl)quinolinium Halides

The hydroxylation of 1-alkyl-3-(2-quinolyl)quinolinium halides by an alkaline solution of K₃[Fe(CN)₆] in aqueous 1,4-dioxane leads to a mixture of 1-alkyl-3-(2-quinolyl)-1,2-dihydro-2-quinolones and 1-alkyl-3-(2-quinolyl)-1,4-dihydro-4-quinolones with predominance of the former. The use of the system of K₃[Fe(CN)₆]/Mg(OH)₂ in aqueous 1,4-dioxane leads to the regiospecific formation of 1-alkyl-3-(2-quinolyl)-1,4-dihydro-4-quinolones.     

Acetylenchemie, 33. Mitt.: Synthese von 2-substituierten Dihydrofuro[2,3-b]chinolinen

Summary The reaction of 3-iodo-4-methoxy-2(1H)-quinolinone (1) and 3-iodo-4,6,8-trimethoxy-2(1H)-quinolinone (2) with 2-methyl-3-butyn-2-ol under modified Heck-conditions gave the 2-substituted derivatives 2-(1-hydroxy-1-methylethyl)-4-methoxyfuro[2,3-b]-quinoline (3) and 2-(1-hydroxy-1-methylethyl-4,6,8-trimethoxyfuro[2,3-b]-quinoline (4). By a subsequent hydrogenation-reaction with a homogeneous catalyst (PtO₂/Rh₂O₃), the furoquinoline-derivatives yielded the dihydrofuro-[2,3-b]quinolines, identified as 2-(1-hydroxy-1-methylethyl-4-methoxy-2,3-dihydrofuro[2,3-b]quinoline (5) (racemic platydesmine) and 2-(1-hydroxy-1-methylethyl)-4,6,8-trimethoxy-2,3-dihydrofuro-[2,3-b]quinoline (6) (racemic precursor of O⁴-methylptelefolonium salt).

     

Hydrothermal Syntheses and Crystal Structures of Two Metal-organic Complexes with 2,3-Pyridinedicarboxylic Acid and 2-Methyl-dipyrido[3,2-f：2＇,3＇-h]quinoxaline Ligands

Two unusual one-dimensional(1-D) compounds,viz.[Co(Medpq)(QUI)·H2O]2n· 2.4nH2O 1 and [Cd(Medpq)(QUI)·H2O]n·nH2O 2,were synthesized by the combination of two different metallic salts and organic ligands,namely 2,3-pyridinedicarboxylic acid(H2QUI) and 2-methyldipyrido[3,2-f:2',3'-h]quinoxaline(Medpq) ligand.The compounds were characterized by elemental analyses,TG,fluorescent emission and single-crystal X-ray diffraction analyses.