A New Route to 1-Oxo-1,2-dihydropyrimido[1,6-a]benzimidazole-4-carboxylates from Ethyl 2-(Benzimidazol-2-yl)-3-(dimethylamino)acrylate Using Solvent-Free Conditions - Meziane, Mohammed Aït Ameur; Rahmouni, Mustapha; Bazureau, Jean Pierre; Hamelin, Jack (Synthesis, 1998)