Hydroxymethylation of pyrimidine mononucleotides with formaldehyde

Abstract

The 5-hydroxymethyl derivatives of the 5′-mononucleotides corresponding to uracil and cytosine, both in the ribose and deoxyribose series, have been obtained by the direct coupling of formaldehyde to the pyrimidine ring, catalyzed by base. Although the final yield is low (about 10 % of the starting material), the method is simple, can be scaled up conveniently, and allows the preparation of the 5-hydroxymethylcytosine mononucleotides in pure form. The 5-hydroxymethyluracil derivatives, not easily separable from the starting unsubstituted compounds, can be obtained pure by nitrous acid deamination of the corresponding 5-hydroxymethylcytosine mononucleotides.