Regioselective Synthesis of Amino Substituted Indazolo[2, 1‐b]phthalazine‐triones and Pyrazolo[1, 2‐b]phthalazine‐2‐carbonitriles Catalyzed by 2‐1′‐Methylimidazolium‐3‐yl‐1‐ethyl Sulfate. (17th April 2014)