Acyliminium ion-olefin cyclization leading to isoindolo[2,1-a]quinoline derivatives

Isoindolo[2,1-a]quinolines 10 , 11 , 12 were synthesized from hydroxylactams 8 or 9 via an N-acyliminium ion-π-olefin nucleophile cyclization reaction.     

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).     

One-pot construction of isoindolo[2,1-a]quinoline system

Polycyclic compounds bearing isoindolo[2,1-a]quinoline system were easily prepared stereo- and regioselectively, and in one-pot, in a tandem fashion containing Povarov’s multicomponent and condensation reactions. Involving a stepwise route for the aza Diels-Alder reaction within the synthesis was suggested.     

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.     

4,5二氢[1,2,4]三氮唑并[4-3-a]喹林衍生物的合成

为了寻找正性肌力作用更强、副作用较小的治疗充血性心力衰竭的正性肌力药物 ,本文参照有关二氢喹啉酮类化合物的结构与正性肌力活性的文献报道[1- 5] ,在喹啉环上并入三氮唑 ,设计合成了 4,5二氢 [1 ,2 ,4]三氮唑并 [4 3 ａ]喹啉衍生物 ,以进一步探索二氢喹啉酮并入三唑环对其活性的影响。其结构经质谱、红外光谱和核磁共振氢谱表征。1　合成路线以苯胺为起始原料 ,经酰化、环合、硝化、还原、硫代、环合得 6 氨基 4,5二氢 [1 ,2 ,4]三氮唑并 [4 3 ａ]喹啉衍生物 :2　实验部分熔点用毛细管法测定 ,温度计未校正。红外光谱仪为ＦＴ ＩＲ1 …     

Angular to linear rearrangement of an isoindolo[2,1-a]quinazoline skeleton

Demethylation of the angular 3-methoxyisoindolo[2,1-a]quinazolin-11(5H)-one by pyridinium chloride led to the rearranged linear 8-hydroxyisoindolo[1,2-b]quinazolin-12(10H)-one.     

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.     

Microwave-assisted combinatorial synthesis of polysubstituent imidazo[1,2-a]quinoline, pyrimido[1,2-a]quinoline and quinolino[1,2-a]quinazoline derivatives

A series of unusual fused heterocyclic compound derivatives, consisting of a pyridine and a imidazole or pyrimidine core, with a bridgehead nitrogen, were successfully synthesized by a microwave-assisted, three-component domino reaction of aldehydes, enaminones, and malononnitrile. In this one-pot reaction, up to five new bonds were formed accompanied by generating the lactam group. This method has the advantages of short synthetic route, operational simplicity, increased safety for small-scale high-speed synthesis, and minimal environment impact.     

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.     

Synthesis of some azeto[2,1-a]isoquinolin-2-ones

Some azeto[2,1-a]isoquinolin-2-ones were synthesized from 2-(3,4-dimethoxyphenyl)ethylamine in three steps in good yield.     

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.     

Hydrogen-bond formation between isoindolo[2,1-a]indol-6-one and aliphatic alcohols in n-hexane

The spectroscopic, kinetic, and equilibrium properties of isoindolo[2,1-a]indol-6-one (I) were studied in n-hexane in the presence and absence of alcohols (X). Hydrogen-bonded-complex formation was found to occur between the alcohol and the ground state as well as the excited state of the I molecule. The spectra of I and its singly complexed derivative (IX) are similar; however, that of IX is red shifted. The extent of red shift increases with the hydrogen-bonding ability of the alcohol. Equilibrium constant measurements were made to determine the hydrogen-bond basicity (beta(2)(H)) for I and the singlet excited (1)I. The beta(2)(H) value for (1)I is found to be about twice that of the ground-state I. Time-resolved fluorescence decay measurements indicate that the reaction of singlet excited I with fluorinated alcohols is diffusion controlled, while the rate of complexation with nonfluorinated (weaker hydrogen bonding) aliphatic alcohols depends on the Gibbs energy change in the complexation reaction. The quantitative correlation between the rate coefficient of complexation of (1)I with alcohols and the Gibbs energy change in the complexation process allowed us to estimate the rate coefficient for the complexation of the ground-state I with alcohols. The formation of the singlet excited hydrogen-bonded complex is irreversible; (1)IX disappears in a first order and an alcohol induced second order reaction. The first order decay is predominantly due to internal conversion to the ground state, the rate of which depends on the ionization energy of the complexing alcohol.     

A new synthesis of imidazo[1,2-a]pyridine and imidazo[2,1-a]isoquinoline derivatives

A new synthesis of imidazo[1,2-a]pyridine and imidazo[2,1-a]isoquinoline derivatives 4 and 8 , respectively by 1,5-dipolar cyclization reactions of stabilized pyridinium N-ylides 3a-e or isoquinolinium N-ylide 7 is described. The starting N-ylides 3a-e and 7 are prepared by the reaction of the corresponding pyridinium salts 1a-e or isoquinolinium salts 6 with N-bis(methylthio)methylene-p-toluenesulfonamide (2) .     

Polycyclic systems: Synthesis of isoindolo[2,1-b]-pyrrolo[1,2-d][2,4]benzodiazocine and isoindolo-[1,2-d]pyrrolo[1,2-a] [1,5]benzodiazocine

The synthesis of isoindolo[2,1-b]pyrrolo[1,2-d][2,4]benzodiazocine 7 and isoindolo[1,2-d]pyrrolo[1,2-a]-[1,5]benzodiazocine 13 are described starting from 2-(2-methoxycarbonyl)benzylphthalimide 1a and ethyl α-bromohomophthalate 9 respectively.     

A Convenient Synthesis of [1,2,3]Triazolo[1,5-a]quinoline

Russian Journal of Organic Chemistry - The reaction of methyl 2-azido-5-bromobenzoate with ethyl 4-(ethylsulfanyl)-3-oxobutanoate was used to synthesize ethyl...