Reduction of pteridines

Abstract

Summary: Reduction: The fifteen possible hydroxy- and polyhydroxypteridines were reduced, chemically and catalytically. Potassium borohydride, sodium dithionite, and potassium (or sodium) amalgam were used as the chemical reducing agents. Hydrogenation over palladium, platinum, and Raney-nickel were used for catalytic reductions. Except 2,4,7-trihydroxypteridine all these were successfully reduced by at least one of the above methods. Hyuroxypteridines lacking a hydroxy group in the pyrazine ring gave tetrahydropteridines and, in some cases, a dihydro-compound as well. Thus 2-hydroxypteridine gave 5,6,7, 8-tetraliydro-2-hydroxypteridine and also 3,4-dihydro-2-hydroxypteridine. The latter is the first example of the reduction of a pteridine in the pyrimidine ring.On the other hand, hydroxypteridines having a hydroxy group in the pyrazine ring gave only dihydro-compounds on reduction. Thus 6-hydroxypteridines gave 7,8-dihydro-6- hydroxypteridines, and 7-hydroxypteridines gave their 5,6- dihydro-derivatives.