Studies on the Synthesis of New 3‐(3,5‐Diamino‐1‐substituted‐pyrazol‐4‐yl)azo‐thieno[2,3‐b]pyridines and 3‐(2‐Amino‐5,7‐disubstituted‐pyrazolo[1,5‐a]pyrimidine‐3‐yl)azothieno[2,3‐b]pyridines