Access to Quinazolines from 2-Nitrobenzaldehyde and Arylamines

Influence of N‐Substitution on Electron Spin Resonance (ESR) Behavior of 2‐(2‐Nitrophenyl)‐1H‐benzimidazole Derivatives

“…[8,9] 2-(2-Nitrophenyl)-1H-benzimidazole (1) [8] To a solution of 2-nitrobenzaldehyde (200 mg, 1.32 mmol) in ethanol (50 ml) was added o-phenylendiamine (143 mg, 1.32 mmol); the resulting solution was refluxed for 8 hr. [8,9] 2-(2-Nitrophenyl)-1H-benzimidazole (1) [8] To a solution of 2-nitrobenzaldehyde (200 mg, 1.32 mmol) in ethanol (50 ml) was added o-phenylendiamine (143 mg, 1.32 mmol); the resulting solution was refluxed for 8 hr.…”

“…1-Acetyl-2-(2-nitrophenyl)-1H -benzimidazole (3) [8] To a stirred solution of 2-2-(nitrophenyl)-benzimidazole 1 (178 mg, 0.745 mmol) and dry N,N-triethylamine (75.3 mg, 0.745 mmol) in anhydrous THF (60 mL) was added acetyl chloride (58.5 mg, 0.745 mmol) under inert atmosphere at 08C. The mixture was maintained at r.t. with stirring for 3 hr, and then poured into water (100 mL).…”

Synthesis, antimicrobial, and mitotic toxicity evaluation of new 6‐substituted 2‐(benzo[4,5]imidazo[1,2‐c]quinazolin‐5(6H)‐yl)acetic acids

“…Thus, the signal of the carbon atom at the 6-position at the range 60.6 to 78.8 ppm was characteristic and confirmed the formation of partially saturated pyrimidine-containing polycyclic system. In 13 C NMR spectrum of compound 5l the signals of carbon atoms in pentafluorophenyl group were registered as a series of hardly distinct low-intensive multiplets, which melted into the background noise due to the C F couplings. However, the presence of the C 6 F 5 group in 5l was clearly confirmed by 19 F NMR (see Supporting Information).…”

“…The most common approaches toward their synthesis involve the condensation of anthranilic acid with 1,2-phenylenediamine in polyphosphoric acid (PPA) [8,10] or the cyclodehydrogenation of 2-nitrobenzaldehyde with 1,2-phenylenediamine in the presence of KHSO 5 , CeCl 3 Á7H 2 O-CuI-I 2 or air as oxidants, followed by reduction of nitro group. [11][12][13][14][15] The cyclization of the resulting 2-(1H-benzo[d]imidazol-2-yl)aniline with different aldehydes, acyl chlorides, or orthoesters gives 6-substituted 5,6-dihydrobenzo-or benzo [4,5]imidazo [1,2-c]quinazolines, respectively. [2,12,[16][17][18][19][20][21][22][23][24][25] Besides, the fusion of 2-substituted 4H-3,1-benzoxazin-4-one with 1,2-phenylenediamine also yields quite good results.…”

Synthesis of a novel series of 4-arylpiperazinyl derivatives linked to a 2-(pyridin-3-yl)-1H-benzimidazole as new Delavirdine analogues

“…7,8 However, structural modifications have been mainly focused on the 4-heteroaryl piperazyne moiety, being the substitution of the indol ring by other heterocycles less explored. 9 To the best of our knowledge, there is not any report about the synthesis of BHAPs containing benzimidazole as the heterocyclic framework. The main reason we adopted to use benzimidazole framework, is the well known bioisosteric equivalence of this ring, respect to 1(H)-Indole.…”