Synthesis of Novel Pyrano[2,3‐ b ]pyridines from α,α′‐Bis(substituted‐benzylidene)cycloalkanones

In this paper, we describe a two‐step synthesis of a series of tacrine analogues. In the first step, α,α'‐bis(substituted‐benzylidene)cycloalkanones are reacted with malononitrile to afford 2‐amino‐3‐cyano‐4 H ‐pyrans. The second step involves the conversion of pyrans to pyrano[2,3‐ b ]pyridines with the use of AlCl 3 as catalyst.