Photocyclization Reactions of N-Substituted 3-(2-Hydroxynaphthalen-1-yl)propenamide Derivatives Accompanied by Liberation of Aliphatic and Aromatic Primary Amines
(E)-3-(2-Hydroxynaphthalen-1-yl)propenoyl- and (E)-3-(2-hydroxynaphthalen-1-yl)-2-methylpropenoyl-protected aliphatic and aromatic primary amines were synthesized and their photolytic behavior in methanol was explored. The results showed that irradiation of the hydroxynaphthyl-propenamide derivatives in a protic polar solvent at wavelengths greater than 280 nm or 340 nm causes rather efficient deprotection reactions to afford the desired amines quantitatively along with fluorescent benzocoumarins.
Convenient and scalable syntheses of 2-substituted glutaconaldehyde salts were accomplished from the corresponding pyridinium salts. Glutaconaldehyde salts were additionally converted into aminopentadienal derivatives. Zincke aldehydes - aminopentadienal derivatives - pyridinium salts - glutaconaldehyde