Synthesis of indeno[2,1‐ b ][1,4]benzothiazine derivatives from 2‐bromoinden‐1‐ones

2‐Bromoinden‐1‐ones 2 were condensed with 6‐substituted 3‐aminopyridine‐2(1 H )‐thiones to produce a new type of 4‐azaindeno[2,1‐ b ][1,4]benzothiazine derivatives 3 . Substituted 6‐phenylindeno[2,1‐ b ][1,4]benzothiazines 4 were also prepared by reacting 2‐bromo‐5‐methoxy‐ and 2,6‐dibromo‐5‐methoxyinden‐1‐ones with o ‐aminobenzenethiol.