Unusual radical addition on a heteroaromatic nitrogen. A convenient access to new pyrimidine derivatives.

A radical generated on the side-chain of a 2- or 4-N-alkylamino-4,6- or 2,6-dichloropyrimidine can cyclise on the nitrogen or on the carbon of the pyrimidine ring depending on its position and on whether an acetyl or a Boc group is present on the extra-nuclear nitrogen.