Reactivity studies on 4‐aminopyrones: Access to benzimidazole and benzimidazolone derivatives

Abstract

Reaction of pyrone 1a or tetronic acid 1b with o‐phenylenediamine derivatives gave enaminone compounds 2. When reacting with different electrophiles, these intermediates allowed versatile access to different heterocyclic structures: when DMA derivatives or triphosgene was used, cyclization occurred through nitrogen, leading to benzimidazoles 3 and benzimidazolones 4, respectively, while reaction with benzaldehyde yielded benzodiazepines 5.

Cyclic 1,3‐diones and their derivatives—As versatile reactive intermediates in the syntheses of condensed fused ring heterocyles

“…Since pyrones and tetronic acid derivatives are wide spread in nature and exhibit a large number of interesting biological activities. It was assumed by Amari and Fodili [169] that it might be advantageous to combine with the above-mentioned structural moieties in the hope of preparing bio-logically relevant compounds. Interaction of 5,6-dihydro-4-hydroxy-6-methyl-2-pyrone (4 6 6 a) or tetronic acid (4 6 6 b) with o-phenylenediamine derivatives 4 6 7 i n ethanol gave enaminones 4 6 8.…”

Synthesis of novel thiazolobenzimidazoles

“…Specifically, this nucleus is a constituent of the vitamin B 12 (O'Neil et al, 2001). The pharmacological activities of the benzimidazole containing moiety have been well documented (Amari et al, 2002 ;Timotou et al, 2013).…”

Synthesis and antimicrobial activities of novel n-substituted 8-(1-alkyl/alkylsulphonyl/alkoxycarbonyl-benzimidazol-2-ylmethoxy)-5-chloroquinolines

“…[1][2][3][4][5][6] Some of the important examples are lansoprazole (anti-ulcer), 7 carbendazim (fungicide), 8 thiabendazole (anthelmintic and fungicide), 9 benperidol (antipsychotic), oxatomide (anti-allergic and anti-asthmatic), 10 etc. Similarly, compounds containing the quinoline nucleus are also known for different therapeutic activities, 11,12 such as chloroquine (antimalarial), 13 chlorquinaldol (antibacterial and antifungal), 14 etc.…”