Sulfur-containing Pyridine Derivatives. LI. 2, 6-Diamino-3-mercaptopyridine Derivatives

1) In Part XXXVIII, it was reported that when 2, 6-diamino-3-methylthiopyridine (III) was refluxed with acetic anhydride, 2, 6-diacetamido-3-methylthiopyridine (VI) was produced. However, it was found that this acetate was a triacetate, the structure of which must be represented by either 2-acetamido-6-acetimido-N-acetyl-3-methylthiopyridine (Va) or 6-acetamido-2-acetimido-N-acetyl-3-methylthiopyridine (Vb), and the relationship between the diacetate (VI) and the triacetate (V) was investigated. 2) Oxidation products of (V) and (VI) were obtained.