Communications

Recyclization of exo-methylene bielectrophiles with 2-aminobenzimidazoles as an access to 3-substituted pyrimido[1,2-a]benzimidazol-2-ones

Yu. A. Kovygin, I. S. Zotova, Kh. S. Shikhaliev

Voronezh State University, 394018 Voronezh, Russian Federation

Abstract: Recyclization of 2-(R-amino)benzimidazoles with N-arylitaconimides affords new 1-R-3,4-dihydropyrimido[1,2-a]-benzimidazol-2(1H)-ones bearing acetanilide moiety at position 3. The similar reaction with α-methylene-γ-butyrolactone gives the analogues containing 2-hydroxyethyl substituent. The domino process starts with the aza-Michael addition of the 3-positioned imine atom of benzimidazoles at the activated exo-methylene group of the bielectrophiles.

Keywords: 3,4-dihydropyrimido[1,2-a]benzimidazol-2(1H)-ones, aminobenzimidazoles, itaconimides, methylenebutyrolactone, domino reactions, heterocyclization, bielectrophiles, aza-Michael addition.

Received: 01.08.2025
Accepted: 08.12.2025

Language: English

DOI: 10.71267/mencom.7892