A short route to 3-alkynyl-4-bromo(chloro)cinnolines by Richter-type cyclization of ortho-(dodeca-1,3-diynyl)aryltriaz-1-enes

Cleavage of ortho-(dodeca-1,3-diynyl)triazenes in HCl or HBr medium and subsequent cyclization of the resulting diazonium salts is investigated. In the absence of a strong electron-withdrawing substituent, the reaction affords 3-alkynyl-4-bromo(chloro)cinnolines as the only product. A methoxycarbonyl group promotes hydrolysis of 4-halocinnolines which results in the formation of by-products: furo[3,2-c]cinnoline and cinnolinone. Substitution of bromine in 3-(alk-1-ynyl)-4-bromocinnolines is achieved with methylamine, Na₂S and ethynylbenzene affording pyrrolo[3,2-c]cinnoline, thieno[3,2-c]cinnoline and 3,4-diethynylcinnoline, respectively.     

Studies on cyclization of o-(alka-1,3-diynyl)arenediazonium salts

The Richter reaction of o-(alka-1,3-diynyl)arenediazonium salts, obtained by diazotization of diacetylenic derivatives of anilines, leads to 3-alkynyl-4-chloro- or 3-alkynyl-4-bromocinnolines and/or 3-alkynyl-4-hydroxycinnolines (the latter cyclize into furo[3,2-c]-cinnolines under the reaction conditions). 3-Alkynyl-4-chlorocinnolines undergo solvolysis in methanol giving rise to 3-alkynyl-4-methoxycinnolines, the subsequent hydrolysis of which also gives furo[3,2-c]cinnolines. Effects of the nature of substituents in the aromatic ring and of the reaction conditions on the product composition and yields have been established. The reaction course has been studied by spectrophotometry. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1693–1700, August, 2008.     

Benzo[b]tellurophene, Dibenzo[b,d]tellurophene, and Their Derivatives. (Review)

Data on the synthesis, reactions, crystal structure, and spectral characteristics of benzo[b]tellurophene, dibenzo[b,d]tellurophene, and their derivatives are reviewed and analyzed.     

Furyl(aryl)methanes and Their Derivatives. 23. Simple Synthesis of Benzo[b]furan Derivatives from 2-Alkylfurans

New derivatives of benzo[b]furan were obtained during successive bromination and dehydrobromination of alkanones containing a gem-difurylmethyl fragment. A mechanism is proposed for the transformations that occur.     

Reactions of 4-cyanobenzo[<Emphasis Type="Italic">c</Emphasis>]pyrylium salts with nitrogen-containing nucleophiles

The recyclization reactions of 4-cyanobenzo[c]pyrylium salts with ammonia, primary amines, and hydrazines have been studied. New derivatives of isoquinoline, benzo-2,3-diazepine, and pyrazolo-[ 5,4-c]isoquinoline have been obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1645–1651, November, 2004.     

(苯并呋喃-2-酰基)二茂铁衍生物的合成与表征

氯乙酰基二茂铁(1)与水杨醛或取代水杨醛在聚乙二醇-400作相转移催化剂条件下,使Williamson反应与Knoevenagel反应在一锅内完成,以40.2%～70.0%的总收率得到了由羰基相连的二茂铁与苯并呋喃组成的结构新颖的闭环产物(苯并[b]呋喃-2-酰基)二茂铁衍生物2a～2n.通过IR,1HNMR,MS和元素分析确认了所合成新化合物2a～2n的结构.     

Novel schemes for the synthesis of pyrrolocoumarins

Two novel schemes have been developed for the synthesis of pyrrolocoumarin derivatives. A series of previously unknown 4,9-dimethylpyrano[3,2-e]indol-7(3H)-ones have been prepared.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No 10, pp. 1524–1532, October, 2004.     

Condensed Pyridine Bases. Synthesis and Reactions of Benzofuro[2,3-c]indeno[2,1-e]-, Benzothieno[2,3-c]Indeno[2,1-e]-, Benzofuro-[3,2-c]Indeno[2,1-e]- and Thieno[2,3:4′,5′]-thieno[3,2-c]indeno[2,1-e]pyridines

Condensation of hetarene carboxaldehydes with phthalide gave 2-(3-hydroxy-1-oxoinden-2-yl)benzo[b]furan and 2-(3-hydroxy-1-oxoinden-2-yl)-5-ethylthieno[2,3-b]thiophene. Starting from hetaryl acetic acids gave 3-(3-hydroxy-1-oxoinden-2-yl)benzo[b]furan and 3-(3-hydroxy-1-oxoinden-2-yl)benzo[b]thiophene. Acylation of 3-hydroxy-1-oxoinden-2-yl-substituted heterocycles using acetic anhydride in the presence of 70% HClO₄ leads to the formation of pentacyclic pyrilium salts. Pentacyclic indenopyridines are prepared by treating the pyrilium salts with ammonia. The reaction of the carbonyl group in the indenopyridines with hydroxylamine, hydrazine hydrate, and in reduction using NaBH₄ has been studied.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 435–443, March, 2005.     

Synthesis and properties of photoacylotropic (2Z)-2-(N-acyl-N-arylaminomethylidene)benzo[b]thiophen-3(2H)-ones with a chiral migrating group

New photochromic (2Z)-2-(N-acyl-N-arylaminomethylidene)benzo[b]thiophen-3(2H)-ones containing L-amino acid derivatives as migrating groups were synthesized. Light irradiation of their solutions at 436 nm leads to the photoinduced acylotropic rearrangement N → O accompanied by migration of the chiral fragment. The bulky N-acyl group causes steric strain thus destabilizing the amide form of compounds and facilitating the photorearrangement. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2690–2696, December, 2005.     

Synthesis and structure of 2-methyl-6-oxo-7,8-dihydrospiro(benzo[h]-triazolo[3,4-b]quinazoline-7,1′-cyclopentane)

The reaction of 4-amino-3-ethoxycarbonyl-1,2-dihydrospiro(naphthalene-2,1-cyclopentane) with benzoyl isothiocyanate led to the corresponding 4-(N-benzoylthioureido) derivative, the cyclization of which gave 4-oxo-2-thioxo-1,2,3,4,5,6-hexahydrospiro(benzo[h]qquinazoline-5,1-cyclopentane). Condensation of the latter with hydrazine hydrate gave 2-hydrazino-3,4,5,6-tetrahydrospiro(benzo[h] quinazoline-5,1-cyclopentane), which formed 6-oxo-1H-7,8-dihydrospiro(benzo[h] triazolo[3,4-b] quinazoline7,1-cyclopentane) in reaction with orthoformice ester. Methylation of the product with methyl iodide led to its 2-methyl derivative.Communication 1, see ref. [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 658–662, May, 2000.     

Synthesis of 2,3-disubstituted 4-oxo-3,4,5,6-tetrahydrospiro-(benzo[h]quinazoline-5,1′-cyclopentanes)

3-Substituted 4-oxo-2-thioxo-1,2,3,4,5,6-hexahydrospiro(benzo[h]quinazoline-5,1-cyclopentanes) were obtained by the reaction of 4-amino-3-ethoxycarbonyl-1,2-dihydrospiro(naphthalene-2,1-cyclopentane) with methyl, phenyl, and benzyl isothiocyanates and cyclization of the obtained thioureas. Condensation of the products with various halides gave 2,3-substituted 4-oxo-3,4,5,6-tetrahydrospiro(benzo[h]quinazoline-5,1-cyclopentanes). The reaction of 4-oxo-2-thioxo-1,2,3,4,5,6-hexahydrospiro(benzo[h]quinazoline-5,1-cyclopentane) with 1,2-dibromoethane and 1,3-dibromopropane led to 6-oxo-7,8-dihydrospiro(benzo[h]thiazolidino[2,3-b]quinazoline-7,1-cyclopentane) and 7-oxo-8,9-dihydrospiro(benzo[h]-perhydrothiazino[2,3-b]quinazoline-8,1-cyclopentane) respectively.A. L. Mndzhoyan Institute of Fine Organic Chemistry, National Academy of Sciences of the Republic of Armenia, Erevan. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 663–667, May, 2000.     

Stereocontrolled synthesis of trans-2-hydroxymethyl-3-methylcyclo-pentanone from (S)-(+)-citronellene

A simple route to trans-2-hydroxymethyl-3-methylcyclopentanone was proposed. The compound is a key intermediate in the synthesis of natural spirocyclic sesquiterpene of the acorane series.     

Intramolecular Cyclization of 4-Isocyanato-3-(2-naphthyl)-1-phenylpyrazole Under Friedel-Crafts Reaction Conditions

4-Isocyanato-3-(2-naphthyl)-1-phenylpyrazole cyclized under the influence of AlCl₃ to give 2H-benzo[h]pyrazolo[4,3-c]isoquinoline.     

Ionic Hydrogenation of 8-Aza-16-thiagona-1,3,5(10),13-tetraene-12,17-diones. Synthesis and Properties of 8-Aza-16-thiagona-1,3,5(10),13-tetraen-17-ones

Ionic hydrogenation of 8-aza-16-thiagona-1,3,5(10),13-tetraene-12,17-diones has been carried out by regioselective reduction of the carbonyl part of the aminovinylketothiolactone group to give 8-aza-16-thiagona-1,3,5(10),13-tetraen-17-ones.     

水介质中三组分一锅合成1-芳基苯并[f]喹啉衍生物

以芳醛、2-萘胺和Meldrum酸为原料, 以水为溶剂, 在回流条件下以三乙基苄基氯化铵为催化剂通过三组分一锅反应, 合成了一系列的1-芳基苯并[f]喹啉衍生物. 该方法具有反应条件温和、产率较高(79%～87%)、环境友好等优点. 产物的结构通过熔点, IR, ¹H NMR和元素分析表征.