Unexpected intermediate 1-phenyl-2-(4-pyridyl)ethanol isolated from benz-aldehyde and 4-picoline condensation reaction.

The unexpected intermediate 1-phenyl-2-(4-pyridyl)ethanol or 4-[2-(1-hydroxy-1-phenyl)ethyl]pyridine was isolated from the condensation reaction of 4-methylpyridine with benzaldehyde to form the model compound 4-styrylpyridine in the absence of a condensing agent. Spectroscopic data (NMR, IR and UV-VIS) gave evidence that the isolated compound is actually the alcohol just before the dehydration which yields the double bond of the 4-styrylpyridine and the structure was confirmed by single-crystal x-ray analysis.. The isolation method from the reaction mixture was difficult at first, but now a 10 % yield has been obtained, not only in powder form but as crystals good enough for R-X structural analysis.