Nitro-heteroaromatic derivatives of amino-acids and peptides. Part V. Photochemical formation of 2-isobutylpyrido[2,3-d]imidazole 1-oxide from 3-nitro-2-pyridyl-DL-leucine

Abstract

The photocyclization of 3-nitro-2-pyridyl-DL-leucine to give 2-isobutylpyrido[2,3-d]imidazole 1-oxide has been investigated spectrophotometrically. The quantum yields of the reaction brought about by irradiation at 366 nm in water have been determined at various hydrogen ion concentrations. The rate of photolysis depends on the degree of protonation of the pyridine nitrogen atom.