High yield synthesis of trans-azoxybenzene versus 2-isopropoxy-4-nitrobenzoic acid: influence of temperature and base concentration

Abstract

This article is dedicated to Prof. José Elguero on the occasion of his 86 th birthday

Synthesis and Biophysical and Biological Studies of N-Phenylbenzamide Derivatives Targeting Kinetoplastid Parasites

“…The starting material dianilines 5b – l were synthesized in two steps from commercially available 4-nitroanilines that were reacted with 4-nitrobenzoyl chlorides to give the 4-nitro- N -(4-nitrophenyl)­benzamide intermediates 4b – l in good yield (65–96%) (Scheme ). The noncommercially available 2-isopropoxy-4-nitrobenzoic acid was synthesized as reported earlier . The reduction of the nitro groups was carried out by Parr hydrogenation with 5% Pd–C or with tin­(II) chloride dihydrate/HCl cat.…”

“… 20 The noncommercially available 2-isopropoxy-4-nitrobenzoic acid was synthesized as reported earlier. 21 The reduction of the nitro groups was carried out by Parr hydrogenation with 5% Pd–C or with tin(II) chloride dihydrate/HCl cat. in EtOH at 50 °C 22 for chlorine-containing compounds ( 5d – g ).…”

“…For the synthesis of halogen-containing bis(pyridine-2carboxamidines) 3c−l, dianiline precursors 5c−l were reacted with N-(tert-butoxycarbonyl)pyridine-2-carbimidothioate (21) in the presence of HgCl 2 and Et 3 N (Scheme 3). 26 We have shown recently that this protocol is useful for the synthesis of bis(arylimidamides) from electron-poor dianilines, where reagent 17 failed to provide the expected products.…”