2-Aminopyridine as a Nucleobase Substitute for Adenine in DNA-like Architectures: Synthesis of Alkynyl -Nucleotides and Their Hybridization Characteristics.

Halogenated 2-aminopyridine was attached to the acetylene terminal of ethynyl -2-deoxy-β-d-ribofuranoside as a nucleobase substitute, and then, the -nucleoside was incorporated into natural DNAs. The resulting chimeric DNA constructed double helical structures with the complementary chimeric DNA. In the duplex, 2-aminopyridine functioned as an adenine analogue that formed a base pair with a non-natural thymine isostere.