Saturated heterocycles. 176 Synthesis and steric structure of quaternary azeto[2,1-a]isoquinoline stereoisomers

Starting from 1-substituted azeto[2,1-a]isoquinoline diastereomers, a number of quaternary salts were prepared. The reactions leading to the quaternary salts were stereospecific, independently of the configuration at C-1, resulting in diastereomers. The steric structures of the new compounds were proved by nmr spectroscopy.     

1,2,3,6,7,11b-Hexahydro-4H-pyrimido[2,1-a]isoquinoline-2-ones

The reaction of 1-methyl-3,4-dihydroisoquinolinium salts with acrylamide forms 2-(2-carbamoylethyl)-1-methyl-3,4-dihydroisoquinolinium salts, which are cyclized by the action of bases to form 11b-methyl-1,2,3,6,7,11b-hexahydro-4H-pyrimido[2,1-a]isoquinolin-2-one. Treatment of this compound with iodomethane yields 5, 11b-dimethyl-2-oxo-1,2,3,6,7,11b-hexahydro-4H-pyrimido[2,1-a]isoquinolinium iodide. The 11b-methylpyrimido[2,1-a]isoquinolin-2-one enters into condensation with aromatic aldehydes, forming the corresponding styryl compounds.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 499–502, April, 1993.     

A new synthesis 2-acyl-1,2,3,6,7,11b-hexahydropyrazino[2,1-a]isoquinolin-4-ones based on N-cyanomethyl derivatives of 2-phenyl-ethylamides of acylglycines

A new route for the synthesis of 2-acyl-1,2,3,6,7,11b-hexahydropyrazino[2,1-a]isoquinolin-4-ones has been studied which includes a stage in which substituted piperazinones are obtained by reductive cyclization of N-cyanomethyl derivatives of 2-phenylethylamides of acylglycines under influence of Raney alloy in formic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 197–201, February, 1993.     

Visible-Light-Driven Sulfonylation/Cyclization to Access Sulfonylated Benzo[4,5]imidazo[2,1-a]isoquinolin-6(5H)-ones

Visible-light-driven sulfonylation/cyclization of N-methacryloyl-2-phenylbenzoimidazoles has been successfully developed. Using commercially available sulfonyl chloride as sulfonylation reagent, a wide range of sulfonylated benzo[4,5]imidazo[2,1-a]isoquinolin-6(5H)-ones with potential antitumor activity were provided in acceptable to excellent yields. This method has the advantages of mild reaction conditions and outstanding functional group tolerance, and provides a new strategy for the development of potential antitumor lead compounds.     

Synthesis of pyrrolo[2,1-a]isoquinolines

Enamine derivatives of 3,4-dihydroisoquinoline obtained by the Ritter reaction form 2,3-dioxo-5,5-RR¹-1-R²-2,3,5,6-tetrahydropyrrolo[2,1-a]isoquinolines with oxalyl chloride.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 963–965, July, 1987.     

Heterocyclic derivatives of naphthalene-1,8-dicarboxylic anhydride. Part I. Nitro-7H-benzimidazo[2,1-a]benz[de]isoquinolin-7-ones

Condensation of o-phenylenediamine with 2-, 3- and 4-nitronaphthalene-1,8-dicarboxylic anhydrides gives, in each case, an isomer mixture. Separation of the mixtures into the six isomeric mononitro-7H-benzimidazo[2,1-a]benz[de]isoquinolin-7-ones is described and the isomers characterised in respect of previously reported data on some isomers; ir and mass spectrum data are reported, the latter showing fragmentation ions which may be used in characterising dyes based on this chromophore. Other new derivatives of 7H-benzimidazo[2,1-a]benz[de]isoquinolin-7-one are also described.     

3-Chloro-6-alkylisoindolo[2,1-a]quinazol-5-ones

3-Chloro-11H-isoindolo[2,1-a]quinazol-5-one was obtained by condensation of o-chloromethylbenzonitrile with 5-chloroanthranilic acid, and its alkylation, electrophilic substitution, and addition reactions were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1129–1131, August, 1977.     

Synthesis of 2-cyclohexylcarbonyl-4-oxoperhydropyrazino [2,1-a]-isoquinoline

2-Cyclohexylcarbonyl-4-oxoperhydropyrazino [2,1-alisoquinoline, an analog of the highly effective anthelmintic prasiquantel, was synthesized from 2-(cyclohexen-1-yl)-ethylamine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1115–1118, August, 1988.     

Saturated heterocycles. 57. Synthesis of 4-substituted-9,10-dialkoxy-1,6,7,11b-tetrahydro-2H-pyrimido[6,1-a]isoquinolin-2-ones

A large number of 4-substituted-9,10-dialkoxy-1,6,7,11b-tetrahydropyrimido[6,1-a]isoquinolin-2-ones were prepared by the reaction of 1-(ethoxycarbonylmethyl)-6,7-dialkoxy-1,2,3,4-tetrahydroisoquinolines with iminoethers. Reaction of the corresponding isoquinoline-1-acetic acid derivatives with iminoethers led to the formation of N-acyl-1,2,3,4-tetrahydroisoquinolin-1-acetamides. In the hydrolysis of the prepared 4-substituted-pyrimido[6,1-a]isoquinolin-2-ones, the corresponding N-acyl-1,2,3,4-tetrahydroisoquinolin-1-acetamides were obtained. While reduction of the 4-phenyl derivative resulted in the corresponding 1,3,4,6,7,11b-hexahydropyrimidinone. The steric structures of the tetrahydro- and hexahydropyrimido[6,1-a]isoquinolines were determined by nmr spectroscopy.     

A novel approach to isoindolo[2,1-a]indol-6-ones

A convenient route to isoindolo[2,1-a]indol-6-ones has been developed starting from the appropriate 2-(N-phthaloyl)benzoic acids. Formation of the acid chlorides with thionyl chloride followed by heating with triethyl phosphite in a suitable solvent resulted in a multistep reaction giving tetracyclic β-ketophosphonates that on reduction with sodium borohydride gave the required indolones in good overall yields. Analogous β-ketophosphonates were also prepared starting with N,N-(1,8-naphthaloyl)-2-aminobenzoic acid and 2-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)benzoic acids although of these only the naphthaloyl product could be reduced with sodium borohydride without cleaving the amide bond in the ring system.     

一锅法合成吡咯并[2,1-a]异喹啉类化合物

以[3+2]环加成反应产物吡咯烷酮作为底物（1）,经过一锅法N-烯丙基化/分子内Heck环合反应合成了12个吡咯并[2,1-a]异喹啉类化合物2a~2l,产物收率50%~79%,其结构经¹H NMR, ¹³C NMR,¹⁹F NMR和HR-MS(ESI)表征。      

Synthesis and some properties of N-unsubstituted pyrrolo[2,1-c]-1,3-diazacycloalkano[1,2-a]pyrazinones

Reactions of methyl 2-(2-formyl-1H-pyrrol-1-yl)alkanoates with unsubstituted aliphatic 1,2-, 1,3-, and 1,4-diamines gave N-unsubstituted pyrrolo[2,1-c]-1,3-diazacycloalkano[1,2-a]-pyrazinones. Some of them show ring-chain tautomerism. Transformations of these compounds led to a number of novel heterocyclic systems: 2,10-dihydro-3H,5H-imidazo[1,2-a]-pyrrolo[1,2-d]pyrazines, 2,3,4,11-tetrahydro-6H-pyrrolo[1??,2??:4,5]pyrazino[1,2-a]pyrimidines, 1,2,3,5,6,10b-hexahydroimidazo[1,2-a]pyrrolo[2,1-c]pyrazines, 1,3,4,6,7,11b-hexahydro-2H-pyrrolo[2??,1??:3,4]pyrazino[1,2-a]pyrimidines, and 2,3,4,5,6,7-hexahydro-1H-pyrrolo[2,1-c]-[1,4,7]triazacycloundecin-8(9H)-one.     

Heterocyclic derivatives of naphthalene-1,8-dicarboxylic anhydride. Part II. Colour and dyeing properties on synthetic fibres of some substituted 7H-benzimidazo[2,1-a]benz[de]isoquinolin-7-ones

The effect on colour resulting from substitution in the phenyl and naphthyl rings of 7H-benzimidazo [2,1-a]benz[de]isoquinolin-7-one (I) is discussed; dycing and fastness properties of these dyes on synthetic fibres are described and the synthesis of some new 1,8-naphthalimides and derivatives of I recorded.     

Dimethylamino-substituted 7H-Benzo[de]pyrazolo[5,1-a]isoquinolin-7-ones and Their Behavior under Vilsmeier-Haack Conditions

The behavior of dimethylamino-substituted 7H-benzo[de]pyrazolo[5,1-a]isoquinoline-7-ones, synthesized for the first time, under conditions of the Vilsmeier-Haack reaction. It has been shown that, on heating with POCl₃ and DMF, they are converted by electrophilic substitution at the position ortho to the dimethylamino group, followed by cyclization of the iminium adduct to a quinazolinium salt. When an acetyl group is present, the Arnold reaction, leading to the formation of a chloroaryl, accompanies the heterocyclization. The rates and proportion of the reaction products depend on the position of the dimethyl groups relative to the pyrazole ring.     

Synthesis of bis(isoindolo-1,2-sym-triazol-5-on-2-yls) and 10,10′-arylenebis[7H-benzo-[de]-sym-triazolo[5,1-a]isoquinolin-7-ones]

Compounds with a bistriazolone structure were obtained by reaction of bisamidrazones of oxalic, isophthalic, and terephthalic acids with phthalic and naphthalic anhydrides. The heterocyclic products of the reaction of the bisamidrazones with phthalic anhydride react with o-phenylenediamine and are converted to arylenebis[1-(3-sym-triazol-5-yl)-2-(benzimidazolyl)phenylenes].     

Synthesis of 2-spiro-(1,2-dihydroperimid-2-yl)-5,5-dialkyl-2,3,5,6-tetrahydropyrrolo[2,1-a]-isoquinolin-3-ones

2,3-Dioxpyrrolo[2,1-a]isoquinolines react with 1,8-naphthalenediamine in 2-propanol in the presence of p-toluenesulfonic acid to give 2-spiro-(1,2-dihydroperimid-2-yl)-5,5-dialkyl-2,3,5,6-tetrahydro-pyrrolo[2,1-a]isoquinolin-3-ones whose structure was confirmed by X-ray analysis. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1849–1854, December, 2008.     

Synthesis of derivatives of the new heterocyclic systems benz[f] imidazo [2,1 -a ] isoquinoline and benz [f] pyrimido [2,1 -a] isoquinoline

The synthesis of several derivatives of benz [f] imidazo [2,1 -a] isoquinoline and benz [f] pyrimido-[2,l-a]isoquinoline, both new heterocyclic structures, is described.     

Synthesis of pyrrolo[2,1-a]isoquinoline hydrazones and oximes

Reactions between 2,3-dioxopyrrolo[2,1-a]-isoquinolines and hydrazines and hydroxylamine afforded the corresponding hydrazones and oximes.Institute of Applied Chemistry, Urals Branch, Russian Academy of Sciences Perm' 614600. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 934–937, July, 1995. Original article submitted May 5, 1995.     

Efficient One-pot Synthesis of Pyrrolo[2,1-a]isoquinoline and Pyrrolo[1,2-a]quinoline Derivatives

A one-pot sequential reaction for efficient synthesis of pyrrolo[2,1-a]isoquinoline and pyrrolo[1,2-a]-quinoline derivatives has been developed. The reaction included firstly the Cu-catalyzed three-component reaction of isoquinoline(quinoline), acetylenedicarboxylate and alkynylbenzene and then Cs₂CO₃-promoted intramolecular cyclization reaction of initially formed 1-alkenyl-2-alkynyl-1,2-dihydroisoquinoline(1,2-dihydroquinoline).