Synthesis Research, Hexanoic Acid And Its Derivatives Of Azoles

A quaternary ammonium peroxotungstphosphate catalyst system with Keggin structure was prepared by tungstic acid, phosphoric acid, quaternary ammonium as raw materials. N-hexanoic acid was prepared from hexyl alcohol with H2O2 as oxidant. 2-pentyl-1H-benzimidazole was synthetised from benzene-1,2-diamine and n-hexanoic acid. 6-Morpholin-4-yl-2-pentyl-1H-benzoimidazole was synthetised from n-hexanoic acid and 5-Chloro-2-nitro-phenylamine. The products were characterized by IR, MS,1H-NMR spectra.Effects of reaction temperature, time, dosage of catalyst, materials ratio on the oxidation of hexyl alcohol were studied. The optimized condition is as follows:temperature was 90℃, time was 6h, hydrogen peroxide:hexyl alcohol= 3:1(moler ratio), catalyst:hexyl alcohol= 1:100(quality ratio). The yield was 55.1%. Supported catalyst was perpared by normal position synthesis, SiO2 was the carrier. The yield of n-hexanoic acid rised up to 63.8%. The yield of n-hexanoic acid decreased sharply when the reation was catalysied by the used catalyst.The formation of imidazole ring contains two steps. The first step is the reaction of carboxyl and amino group, the second step is the condesation between the carbonyl and amino. The acidity situation and high temperature are beneficial to the formation of the ring. Acyl chloride was synthetised from n-hexanoic acid. Benzene-1,2-diamine and acyl chloride (moler ratio= 1:3) were refluxed in acetic acid, and the yield of 2-pentyl-lH-benzimidazole was 86%.5-Chloro-2-nitro-phenylamine was firstly reducted by Fe powder, then the product and acyl chloride(moler ratio= 1:3) were refluxed in acetic acid, the yield of 6-Morpholin-4-yl-2-pentyl-lH-benzoimidazole was 37.3%.