De Novo Pyridine Ring Synthesis and Methylsulfinyl Displacement by Amines

Significance

Reported is the synthesis of multisubstituted 6-methylsulfinyl pyridine and the subsequent functionalization by displacement of the methylsulfinyl group with nucleophiles. The starting materials are commercially available and/or easily synthesizable. The de novo pyridine construction proceeds in a moderate yield (44%), whereas the oxidation step is selective and high yielding. Yields from the nucleophilic displacement range from poor to moderate. The substrate scope was insufficiently studied as the nucleophiles used were predominantly primary amines. Oxidation of thiomethyl group to the methylsulfinyl is required as the former does not undergo displacement reactions.