Synthesis of some novel N‐alkyl/acyl/aroyl 2‐(chroman/6‐bromochroman‐2‐yl)‐1H‐benzimidazoles using ionic liquids and their antibacterial activity

Abstract

magnified image Synthesis of some novel N‐substituted 2‐(chroman/6‐bromochroman‐2‐yl)‐1H‐benzimidazoles by the condensation of 3,4‐dihydro‐2H‐chroman‐2‐carboxylic acid and 6‐bromo‐3,4‐dihydro‐2H‐chroman‐2‐carboxylic acid with o‐phenylenediamine in ionic liquid (IL) [bmim]BF4 and subsequent reactions at the benzimidazole‐NH with different types of electrophiles in ILs [bmim]BF4 = 1‐butyl‐3‐methylimidazolium tetrafluoroborate, [bmim]PF6 = 1‐butyl‐3‐methylimidazolium hexafluorophosphate and [buPy]BF4 = butylpyridinium tetrafluoroborate in the presence of sodium hydroxide as a base have been reported. All the synthesized compounds were screened for their antibacterial activity. Some compounds exhibited promising antibacterial activity against Staphylococcus aureus and Salmonella typhimurium when compared to Cephalexin as a reference standard. J. Heterocyclic Chem., (2010).

Synthesis, characterization, molecular structures, cytotoxic and antibacterial activities of N,N′-diaryl-o-phenylenediamines

“…m. p. 219°C. 1 The procedure was similar to the synthesis phenylendiamine 1. Pd(OAc) 2 (0.25 g, 1.12 mmol); tBu 3 P (0.68 g, 3.37 mmol); 1,2-dibromo-benzene (6.6 g, 28 mmol); 2,6-diisopropylaniline (9.90 g, 56 mmol); NaOtBu (8.06 g, 84 mmol).…”

“…In order to carry out a structural modification on phenylene diamines, Harlan et al reported a simple catalyzed coupling reaction to isolated N,N-diaryl-o-phenylenediamine derivatives [15]. Base on that, in this paper, we describe the molecular structure and their biological activity of a short series of N,N 0 -aryl-o-phenylenediamines (Scheme 2) such as N,N 0 -2,6-dimethylphenyl-o-phenylenediamine (1), N,N 0 -2,4,6-trimethylphenyl-o-phenylenediamine (2), and N,N 0 -2,6-diisopropylphenyl-o-phenylenediamine (3).…”

“…o-Phenylenediamines (o-PDA) derivatives have been shown as an important class of synthons in several heterocyclic [1], organic [2], organometallic [3], and coordination complexes [4]. Some phenylenediamines derivatives have been showed important biological effects such as antifungal [5], anticancer [6], and antimutagenic [7].…”