Photolysis of dimethoxynitrobenzyl-"caged" acids yields fluorescent products.

Carboxylic acids conjugated with 4,5-dimethoxy-2-nitrobenzyl photoremovable protecting group are well known and widely used for biological studies. In this paper, we study the photolysis of likewise "caged" acetic, caprylic and arachidonic acids. Unexpectedly, we observed huge growth of fluorescence emission at ~430 nm during photolysis.

New approach toward the synthesis of deuterated pyrazolo[1,5-]pyridines and 1,2,4-triazolo[1,5-]pyridines.

An efficient and operationally simple synthesis of 7-deuteropyrazolo[1,5-]pyridine and 7-deutero-1,2,4-triazolo[1,5-]pyridine derivatives using α-H/D exchange of 1-aminopyridinium cations in basic DO followed by a 1,3-cycloaddition of acetylenes and nitriles is presented. A high regioselectivity and a high degree of deuterium incorporation were achieved. The procedure was applied for several 4-R-1-aminopyridinium cations (R = H, Me, OMe).