Synthesis and anticonvulsant activity of benzimidazo[1, 2-c]quinazolines

Synthesis of some new mono, bis-indolo[1, 2-c]quinazolines: evaluation of their antimicrobial studies

“…31 The formation of title compounds (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) were confirmed by the disappearance of the absorption maxima at 3330-3400 cm -1 , which are ascribed to the vibrations of NH group of the indole ring; at the same time the appearance of a new maximum at 1360-1380 cm -1 , which is characteristic for indolo [1,2-c] quinazoline ring with a tertiary nitrogen atom, appears. 32 The exhibited chemical shifts obtained from 1 H NMR spectra of compounds 1-20 supported the proposed structures of the compounds.…”

“…Finally, in the title compounds disappearance of signals corresponding to -NH of indolyl ring and CH=N protons supports the indoloquinazoline ring structure. 32 Further, 13 C NMR spectra showed confirmatory signals of the C=N carbon atoms and the aromatic carbons in the range of 148.9-167.9 ppm and 110.7-157.9 ppm respectively. 33 The structures of all intermediates and title compounds were further confirmed by mass spectral analysis.…”

6‐Substituted Indolo[1,2‐c]quinazolines as New Antimicrobial Agents

“…In all the azomethines (Ia -Ij, 2-o-arylidineaminophenylindoles) the characteristic IR peaks for the -CHO and -NH 2 groups at 1680 -1695 cm -1 and 3380 -3440 cm -1 are absent and the characteristic peak for the CH=N around 1610 -1635 cm -1 is observed, which indicates the effective condensation of the aldehyde group with the amino group of the key indole derivative (2-o-aminophenylindole) [36]. The formation of the final 6-substituted indolo[1,2-c]quinazolines was identified by disappearance of m (NH-) absorption band at 3400 -3330 cm -1 present in 2-o-aminophenylindole, and the appearance of the absorption band at 1360 -1380 cm -1 characteristic for the indoloquinazoline ring with a tertiary nitrogen atom (C-N) [37].…”

Synthesis and antimicrobial activities of a new class of 6-arylbenzimidazo[1,2-c]quinazolines

“…35 The oxidative cyclisation of compounds 1-10 to 11-20 were accompanied by the disappearance of the absorption maxima at 3150-3300 cm -1 , which are ascribed to the vibrations of NH group of the benzimidazole ring; at the same time the appearance of a new maximum at 1360-1388 cm --1 , which is characteristic for benzimidazoquinazoline ring with a tertiary nitrogen atom, appears. 23,36 The 1 H NMR spectra of the compound A as well as its derivatives have been recorded in CDCl 3 /DMSO-d 6 using TMS as internal standard. In the spectra of 2-(o-aminophenyl) benzimidazole (A), signals at d 6.4 and d 8.25 ppm were appeared corresponding to free amino and imidazolyl protons respectively.…”

“…7 Moreover, benzimidazoles and quinazolines are of the most extensively studied classes of heterocyclic compounds, and have received much attention from synthetic organic as well as medicinal chemists, because of the diverse range of their biological activities 8,9 and their applications in several areas as materials in electronics, in electrochemistry as anticorrosive agents, as polymers or optical materials and fluorescent tags in DNA sequencing. [10][11][12] In general, quinazoline compounds have been well-recognized for their pharmacological properties, such as anti-inflammatory, 13,14 antihypertensive, 15 anti-HIV, 16 bronco-dilatory, 17 antiallergic, 18 anti-cancer, [19][20][21] anticonvulsant, 22,23 antihelmintic, 24 analgesic, 25 antimalarial 26 and antimicrobial 27 activities. Literature survey reveals that, benzimidazo [1,2-c] quinazoline derivatives also show various biological activities, 23,[28][29][30] such as anticancer, antiviral, antimicrobial, anti-inflammatory and anticonvulsants.…”