ChemInform Abstract: Synthesis of Pyrazolo[4′, 3′:3, 4]pyrido[1, 2‐a]benzimidazoles and Related New Ring Systems by Tandem Cyclization of vic‐Alkynylpyrazole‐4‐carbaldehydes with (Het)aryl‐1, 2‐diamines and Investigation of Their Optical Properties. Issue 37 (September 2015)