Synthesis of [1,2-a] benzimidazolo-1,3,5-triazin-2-thione, [1,2-a] benzimidazolo-1,3,5-thiadiazin-2-thione, [1,2-a] benzimidazolo-1,3,5-triazin-2-amine, and [1,2-a] benzimidazol-2-yl amidrazone

N-benzimidazol-2-yl imidate type 1 reacts with thiourea, carbon disulfide, cyanamide, and hydrazide to give, respectively, [1,2-a] benzimidazolo-1,3,5-triazin-2-thione 2, [1,2-a] benzimidazolo-1,3,5-thiadiazin-2-thione 3, [1,2-a] benzimidazolo-1,3,5-triazin-2-amine 4, and [1,2-a] benzimidazol-2-yl amidrazone 5 with good yields. Structures elucidation of all newly synthesized heterocyclic compounds was based on the data of IR, 1H NMR, 13C NMR, elemental analysis, and MS of some products. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:279–283, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20618