Karnam Jayarampillai Rajendra Prasad

Simple and Convenient Methods for the Synthesis of Indolo[3,2-c]acridines

The reaction of 2,3,4,9-tetrahydro-1H-carbazol-1-ones with anthranilic acid in POCl3 yielded 7-chloro-5,6-dihydro-13H-indolo[3,2-c]acridines, while the same on reaction with isatin under the Pfitzinger reaction condition yielded 5,6-dihydro-13H-indolo[3,2-c]acridine-7-carboxylic acids. The latter reaction was carried out in different basic condition, because of, NaOH yielded more yield instead of KOH. Both the obtained products were treated with Pd/C in diphenyl ether to yield 13H-Indolo[3,2-c]acridines.

Convergent Synthetic Route to Pyrano[2,3-a]carbazole by Multicomponent Reaction

Abstract NaHCO3 has been found to be an efficient base catalyst for the synthesis of pyrano[2,3-a]carbazoles from 1-hydroxycarbazoles by multicomponent reaction using solvent-free grinding methods. In this case, the products have been found in good yields, without formation of any side product. GRAPHICAL ABSTRACT

Elegant One-Pot Synthesis of Quinolino[2′,3′:7,6]-cyclohept[1,2-b]indole Through Friedländer and Pfitzinger Annulation Reaction

Abstract A rapid, simple, and efficient method for the preparation of various quinolino[2′,3′:7,6]cyclohept[1,2-b]indoles has been developed through the Friedländer and Pfitzinger condensations of 1-oxo-cyclohept[b]indole with o-amino benzophenone and isatin respectively. Reactions were performed by under different reaction conditions.

Novel 13H-indolo[3,2-c]acridines and their methyl derivatives

7-Phenyl-13H-indolo[3,2-c]acridines (2a–e) have been prepared from 2,3,4,9-tetrahydro-1H-carbazol-1-ones (1a–e) via the intermediate 5,6-dihydro-derivatives (3a–e), and 13H-indolo[3,2-c]acridines (8a–e) from the 1-(N-phenylamino)carbazoles (7a–e). Methylations of 2 and 8 have been carried out, and UV spectral studies on the title compounds and the methylated products are presented, along with plausible mechanisms for the formation of the final compounds.

Efficient Protocol for Synthesis of Pyrazolo[3,4-a]acridines

Abstract A new class of pyrazolo[3,4-a]acridines have been prepared. The synthon acridones were obtained in very good yield by a one-pot reaction of 2-amino-5-chloro or nitro substituted benzophenones with 1,3-cyclic diketones in the presence of freshly prepared Eaton’s reagent without solvent, using Friedländer synthesis. The intermediates were reacted with ethylformate followed by hydrazine hydrate to afford pyrazolo[3,4-a]acridines. All of the compounds were purified by recrystallization only, and no chromatographic workup was required. The structures of the synthesized compounds were deduced by spectroscopic techniques, including single-crystal x-ray diffraction. GRAPHICAL ABSTRACT

Synthesis, DNA binding and cytotoxic evaluation of aminoquinoline scaffolds

AbstractAn effortless synthetic route has been developed for the synthesis of a new class of aminoquinoline substituted isoindolin-1,3-diones from regio-isomerical hydrazinylquinolines with phthalic anhydride in presence of Eaton’s reagent. DNA binding studies of selected isomeric compounds showed interaction with DNA via intercalation mode with higher binding affinity of 4-substituted quinolines rather than 2-substituted counterparts. Further, all compounds were screened for cytotoxic activity against three human cancer cell lines, among them compound 2c outranged standard doxorubicin against CCRF-CEM cell line. Graphical AbstractA convenient route to synthesize aminoquinoline substituted isoindolin-1,3-diones using Eatons reagent as a catalyst has been explored. The DNA binding and in vitro cytotoxicity studies revealed the importance of aminoquinoline scaffolds in cancer treatment.

InCl3-Assisted Synthesis of Pyrano[2,3-a]carbazoles via Multicomponent Reaction

Abstract A facile, efficient, and environmentally friendly protocol for the synthesis of pyrano[2,3-a]carbazoles has been developed by one-pot multicomponent reaction of benzaldehyde/isatin with malononitrile and 1-hydroxycarbazoles in the presence of InCl3 as catalyst. GRAPHICAL ABSTRACT

Facile Synthesis of Substituted Furo- and Pyrano-Carbazoles

Abstract Simple and efficient method for the synthesis of substituted furo- and pyrano-carbazole derivatives from 1-hydroxycarbazoles was described. GRAPHICAL ABSTRACT

Syntheses of Substituted Furo- and Pyrano-(2,3-a)carbazoles from 2-Cinnamoyl-1-hydroxycarbazoles

Reaction of 2-cinnamoyl-1-hydroxycarbazoles 2a - d, with phenacyl bromide, mercuric acetate and H2O2/NaOH under different reaction conditions yielded 2-benzoyl-3-styryl-furo[2,3-a]carbazoles 3a-d, 2-benzylidene-furo[2,3-a]carbazol-3(10H)-ones 4a - d and 3-hydroxy-2-phenylpyrano- [2,3-a]carbazol-4(11H)-ones 5a - d, respectively.

7,8,9,10-Tetra-hydro-2-methyl-cyclo-hepta-[b]indol-6(5H)-one.

The title compound, C14H15NO, was synthesized from 2-hydroxymethylenecycloheptanone via a Japp–Klingemann acid-catalyzed cyclization. The seven-membered ring exhibits a slightly distorted envelope conformation. N—H⋯O hydrogen bonds form a centrosymmetric dimer; C—H⋯O hydrogen bonds and π–π stacking interactions (the centers of the atoms involved in the stacking interaction are separated by 3.504 Å) give rise to another type of centrosymmetric dimer. In combination, these interactions create a stair-like chain of molecules that interacts only loosely with neighboring chains via van der Waals interactions and weak C—H⋯π contacts.