An Energy Rich Phosphate from 2 -Methylimidazole through Nonenzymatic Photophosphorylation * ‘ * * *
Sensitized photooxidation of imidazoles in aqueous solution and in the presence of inorganic phosphate afforded organic phosphates with yields up to 30%. The major phosphorylated product of oxidation of 2-methylimidazole was isolated and identified as the monophosphate of 4,5-dihydroxy-2-methylimidazoline with pKₐ values of 2.0, 5.2, and 9.8. The compound is energy rich in aqueous solution and hydrolyses in alkaline or neutral solutions irreversibly (ΔHₕyd = -9.8 kcal/mole). For the hydrolysis at pH 7 an activation-enthalpy of 25 kcal/mole and -entropy of 8 cal/deg.mole was observed. Be²⁺ ions catalyse the hydrolysis.