Synthesis of some imidazole‐ and pyrazole‐ derived chelating agents

Abstract

Procedures involving condensation of o-phenylenediamines with carboxylic acids, and reaction of bifunctional alkyl halides with bifunctional nucleophiles are described. Syntheses are reported of 2,6-bis-(2-benzimidazyl>pyridine, 1,3-bis(2-benzimidazyl)2-thiapropane, 1,7-bis(2-benzimidazyl)2,6-dithiaheptane, 2-hydroxymethyl-5,6-dimethylbenzimidazole, 2-chloromethyl-5,6-dimethylbenzimidazole hydrochloride, 1,7--bis(5,6-dimethyl-2-benzimidazyl)-2,6-dithiaheptane, 3,6-bis(l-pyrazolyl)pyridazine, 2-(2-hydroxy-3-rnethyl--phenyl)benzimidazole, 2-(2-hydroxyphenyl)benzimidazole, 5-(2.hydroxphenyl)3-methyl-l-phenylpyrazole, 3(5)-(2-hydroxyphenyl)5(3)methylpyrazole, 3(5)-(2-hydroxyphenyl>5(3)phenylpyrazole, and 1,3-bis((S-methyl-pyridy1)imino)isoindoline.

Copper complexes of polyfunctional phthalazines. Mononuclear and polynuclear derivatives

“…This direct fusion method, which we have used routinely for a number of years, provides good yields of the disubstituted isoindolines and is a more efficient procedure than previously reported syntheses involving phthalonitrile (23, 24) and 1,3-diiminoisoindoline (25) as starting materials. The synthesis of the 5-methyl isoindoline by this route was recently reported by Addison and coworkers (26).…”

Structure of [2,6-bis(2-benzimidazolyl)pyridine]dichlorocopper(II) dimethylformamide

“…Preparation of crystals: 0.311g (1 mmol) of ligand, bzimpy, synthesized by the method of Addison & Burke (1981), was dissolved in 20 ml ethanol and then mixed with 0.17 g (1 mmol) of CuC12.2H20 in the same solvent. The resulting precipitate was separated by filtration and recrystallized from 300 ml hot DMF.…”

Reactions of rhodium and iridium salts with multidentate N-heterocycles

“…Hydrated rhodium tribromide and rhodium(IlI) perchlorate were prepared as described elsewhere [4]. Polydentate Nheterocycles-2,6-bis(benzimidazolyl)pyridine and its N-methylated derivative were prepared according to literature methods [5][6][7]. The IR (nujol mull and KBrl and electronic (Nujol mull and DMF solution) spectra were recorded on Carl Zeiss SPECORD 75-IR and Hitachi 150-20 spectrophotometers, respectively.…”