A Convenient Synthesis of Some New 1, 3, 4‐Thiadiazoles, Thiazoles, Pyrazolo[1, 5‐a]pyrimidines, Pyrazolo[5, 1‐c]triazine, and Thieno[3, 2‐d]pyrimidines Containing 5‐Bromobenzofuran Moiety. (11th August 2015)