Synthesis of 1,4-Dihydropyridines and Their Fluorescence Properties

We have successfully synthesized 3,4,5-substituted 1,4-dihydropyridines (1,4-DHPs) from amine hydrochloride salts, aldehydes, and acetals in good yields without the addition of a catalyst. The synthesized 1,4-DHPs exhibit various wavelengths of fluorescence, which could be tuned by changing the substituents at the 3- and 5-positions of the 1,4-DHPs.