Synthesis and reactions of 7,8-dihydro-8-methylpterin and 9-methylguanine 7-oxide

Abstract

7,8-Dihydro-8-methylpterin (3) has been prepared by reduction of [2-amino-5-(p-chlorophenylazo)-6-hydroxypyrimidin-4-yl(methyl)amino]acetaldehyde (7; X = N₂C₆H₄Cl) and by reduction of the corresponding 5-nitro-pyrimidine. The addition of nucleophilic reagents to the dihydropterin is reported and further reactions with the products are described. In a new purine synthesis the 5-nitropyrimidine (7; X = NO₂) is cyclised to 9-methyl-guanine 7-oxide (26) with sodium hydroxide. The latter undergoes typical N-oxide reactions and has been used for the synthesis of other purine derivatives.