Pteridines bearing acetylene‐containing sidechains at c‐2:Preparation and attempted cycloaddition reactions

Abstract The preparation of a series of pteridine derivatives 1a‐d bearing S‐, O‐, or C‐linked ω‐alkynyl side chains at C‐2 is described. Furthermore, an improved synthesis of 2‐chloropteridine is proposed. Compounds 1a‐d were found not to undergo intramolecular cycloaddition reactions under thermolytic conditions.