2-Phenyl- and 2-benzamido-benzimidazoles

Abstract

2-Phenylbenzimidazoles I-VI with chlorine atom or methoxy group on the benzene ring were prepared by a modified method. Acylation of 2-aminobenzimidazole with substituted benzoyl chlorides afforded the 2-benzamidobenzimidazoles VII-XXXVI. All these compounds were tested for anthelmintic and coccidiostatic activity.

(Thio)Amidoindoles and (Thio)Amidobenzimidazoles: An Investigation of Their Hydrogen‐Bonding and Organocatalytic Properties in the Ring‐Opening Polymerization of Lactide

“…[16] A similar procedure [17] was achieved to synthesize amidobenzimidazoles 5 a and 5 c in 45 and 73 % yield, respectively, from the benzoyl chloride derivatives and 2-amino-5,6-dimethyl-benzimidazole. [18] Thioamido-related compounds were obtained by thionation of the oxo compounds using Lawessons reagent in toluene heated at reflux.…”

Chemistry and Biology of Synthetic and Naturally Occurring Antiamoebic Agents

“…Discovery of 5,6-dimethyl-1-(α- D -ribofuranosyl)benzimidazole, an integral part of the chemical structure of vitamin B 12 , has generated considerable interest in the area of benzimidazole nucleosides and nucleotides. , Benzimidazole and its derivatives are widely used in searches for new drugs. − Recently, interest in the synthesis and characterization of transition metal complexes of the benzimidazole ligands has been stimulated as a result of their biological and pharmacological activity. − Benzimidazoles are commonly synthesized by coupling o -phenylenediamine with carboxylic acids . Alternatively o -phenylenediamine can be treated with benzaldehydes, followed by cyclization of the intermediate Schiff base in the presence of various oxidants such as nitrobenzene, , 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, benzofuroxan, and MnO 2 . Sondhi et al described one-step synthesis of pyrimidobenzimidazoles (Scheme ), in which isothiocyanatobutanal 2.024 was condensed with o -phenylenediamine 2.023 in refluxing methanol at pH ≈ 5 to give pyrimidobenzimidazole derivatives 2.025 in 18−46% yield. , …”

“…[99][100][101][102][103][104] Benzimidazoles are commonly synthesized by coupling o-phenylenediamine with carboxylic acids. 105 Alternatively o-phenylenediamine can be treated with benzaldehydes, followed by cyclization of the intermediate Schiff base in the presence of various oxidants such as nitrobenzene, 105,106 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, 107 benzofuroxan, 108 and MnO 2 . 106 Sondhi et al described one-step synthesis of pyrimidobenzimidazoles (Scheme 6), in which isothiocyanatobutanal 2.024 was condensed with o-phenylenediamine 2.023 in refluxing methanol at pH ≈ 5 to give pyrimidobenzimidazole derivatives 2.025 in 18-46% yield.…”

Synthesis and alkylation of 6-(1H-benzimidazol-2-yl)-5-methylthieno[2,3-d]pyrimidin-4(3H)-ones

“…It is known that benzimidazoles are readily prepared by the reaction of carboxylic acids with orthophenylenediamines [4][5][6][7][8] when heating in the acidic medium like polyphosphoric acid. The reaction of 5methyl-4-oxo-3,4-dihydrothieno[2,3-d]pyrimidine-6-carboxylic acid 1a [9] with ortho-pnenylediamine 2a was carried out in the polyphosphoric acid medium for 5 h at 190°С when heating, but the desired 6-(1H-benzimidazol-2-yl)-5-methylthieno[2,3-d]pyrimidin-4(3H)-one was not isolated after this procedure.…”