✍ Scribed by Nehal M. Elwan
No coin nor oath required. For personal study only.
Reaction of 1‐amino‐3‐arylpyrido[1,2‐a]benzimidazole‐2,4‐dicarbonitrile (1) with dimethylformamide‐dimethylacetal (DMF‐DMA) gave 1‐[N,N‐(dimethylaminomethylene)amino]‐3‐arylpyrido[1,2‐a]benzimidazole‐2,4‐dicarbonitrile (2). Compounds (1) reacted with triethylorthoformate yielding 1‐[N‐(ethoxymethylene)amino]‐3‐arylpyrido[1,2‐a]benzimidazole‐2,4‐dicarbonitrile (3). 3‐Amino‐4‐imino‐5‐aryl‐6‐cyanopyrimido[5′,4′:5,6]pyrido[1,2‐α] benzimidazole (4) was synthesized via condensation of either (2) or (3) with hydrazine hydrate. Reactions of (4) with acetic anhydride, ethyl chloroformate or aryl isothiocyanate yielded the respective derivative of the new ring system namely 1,2,4‐triazolo[2″,3″:6′,1′]pyrimido[4′,5′:2,3]pyrido[1,2‐a]benzimidazole (5–7).
📜 SIMILAR VOLUMES
## Abstract For Abstract see ChemInform Abstract in Full Text.
## Abstract magnified image 4‐Acetyl‐5‐methyl‐1‐phenyl‐1__H__‐pyrazole reacts with dimethylformamide dimethylacetal (DMF‐DMA) to afford the corresponding (__E__)1‐(5‐methyl‐1‐phenyl‐1__H__‐pyrazol‐4‐yl)‐3‐(__N,N__‐dimethylamino)‐2‐propen‐1‐one. The latter product undergoes regioselective 1,3‐dipol