103855-44-3

Upstream product

• 83-34-1 3-Methylindole 
• 870-24-6 2-chloroethanamine hydrochloride 

Downstream Products

• 126718-24-9 10-methyl-1,2,3,4-tetrahydropyrazino[1,2-a]indole 
• 21689-25-8 10-methyl-1-phenyl-1,2,3,4-tetrahydropyrazino[1,2-a]indole 

Relevant academic research and scientific papers

Highly efficient one-pot synthesis of 1-substituted-1,2,3,4- tetrahydropyrazino[1,2-a]indoles

A practical and general one-pot synthesis of 1-substituted-10-methyl-1,2,3, 4-tetrahydropyrazino[1,2-a]indoles is described. The approach uses 2-(3-methyl-1H-indol-1-yl) ethylamine, benzotriazole and aldehydes in the presence of catalytic amount of acid catalysts (AlCl3, ZnCl 2, ZnBr2, p-TsOH, CH3SO3H) and proceeds in high yields via iminium cation intramolecular cyclization. The mechanism of the observed intramolecular cyclization reaction has been investigated theoretically by means of PM3 semiempirical method and results were consistent with the experimental results.

Novel synthesis of 1,2,3,4-tetrahydropyrazino[1,2-a]indoles

Condensation of 2-(3-methyl-1H-indol-1-yl)ethylamine (7) with benzotriazole and formaldehyde gave 2-(1H- 1,2,3-benzotriazol-1-ylmethyl)-10-methyl-1,2,3,4-tetrahydro- pyrazino[1,2-a]indole (8) in 96% yield. Nucleophilic substitutions of the benzotriazolyl group in 8 with NaBH4, NaCN, triethyl phosphite, allylsilanes, silyl enol ether and Grignard reagents afforded novel 10-methyl-1,2,3,4-tetrahydropyrazino- [1,2-a]indoles 9a-i in 78-95% yields.

Construction of pyrrole- and indole-fused CF3-piperazine derivatives

A series of pyrrole- and indole-fused trifluoromethyl-functionalized piperazine derivatives were constructed in moderate to good yields with excellent chemoselectivities via a Pictet-Spengler reaction under mild and operationally simple conditions. The synthetic utility of this protocol was further extended by the facile preparation of indole-fused CF3-1,4-diazocane and enantioenriched CF3-piperazines via a vinylogous Pictet-Spengler reaction and an asymmetric Pictet-Spengler reaction, respectively.

Organocatalytic enantioselective multicomponent synthesis of pyrrolopiperazines

The first organocatalytic multicomponent synthesis of enantioenriched pyrrolopiperazines is reported. These biologically relevant fused tricyclic products were obtained under catalytic iminium activation through a reaction sequence involving an enantioselective Michael addition followed by an iminium ion trapping via Pictet-Spengler cyclization (MAPS sequence). Substantial possibilities for variation on the three reaction partners [β-keto ester, enal and N-(2-aminoethyl)pyrrole] along with excellent enantioselectivities are the highlights of the present transformation.

Synthesis and antibacterial activity of substituted 1,2,3,4- tetrahydropyrazino [1,2-a] indoles

A series of substituted 1,2,3,4-tetrahydropyrazino [1,2-a] indole derivatives have been synthesized and tested against the Gram positive and Gram negative strains of bacteria namely Staphylococcus aureus (MTCCB 737), Salmonella typhi (MTCCB 733), Pseudomonas aeruginosa (MTCCB 741), Streptomyces thermonitrificans (MTCCB 1824) and Escherichia coli (MTCCB 1652). All synthesized compounds showed mild to moderate activity. However, compounds 4d-f were found to have potent activity against pathogenic bacteria used in the study. Their MIC ranged from 3.75 to 60 μg/disc. In vitro toxicity tests demonstrated that toxicity of 4d-f was not significantly different than that of gentamycin. However, at higher concentration (1000-4000 μg/ml) difference was highly significant.

Synthesis and antifungal activity of substituted-10-methyl-1,2,3,4- tetrahydropyrazino[1,2-a]indoles

Series of substituted-10-methyl-1,2,3,4-tetrahydropyrazino[1,2-a]indoles derivatives have been synthesized and examined for their activity against pathogenic strains of Aspergillus fumigatus (ITCC 4517), Aspergillus flavus (ITCC 5192) Aspergillus niger (ITCC 5405) and Candida albicans (ITCC No 4718). All synthesized compounds showed mild to moderate activity, except for 2-substituted-10-methyl-1,2,3,4-tetrahydropyrazino[1,2-a]indoles 6a-d. The most active 1-(4-chlorophenyl)-10-methyl-1,2,3,4-tetrahydropyrazino[1,2-a]indole 4c exhibited a MIC value of 5.85 μg/disc against A. fumigatus and 11.71 μg/disc against A. flavus and A. niger in disc diffusion assay. Anti-Aspergillus activity of active compound 4c by microbroth dilution assay was found to be 15.62 μg/ml in case of A. fumigatus and 31.25 μg/ml with A. flavus and A. niger. The MIC90 value of the most active compound by percent germination inhibition assay was found to be 15.62 μg/ml against A. fumigatus. The MIC90 values of substituted-10-methyl-1,2,3,4- tetrahydropyrazino[1,2-a]indoles against C. albicans ranged from 15.62 to 250 μg/ml. The in vitro toxicity of the most active 1-(4-chlorophenyl)-10-methyl- 1,2,3,4-tetrahydropyrazino[1,2-a]indole 4c was evaluated using haemolytic assay, in which the compound was found to be non-toxic to human erythrocytes up to a concentration of 312.50 μg/ml. The standard drug amphotericin B exhibited 100% lysis at a concentration of 37.5 μg/ml.