Solvent-free or low-solvent large-scale preparation of chloropyrimidine and analogues.

Chloropyrimidine or other N-containing aromatic heterocyclic analogues can be efficiently prepared from the corresponding hydroxylated precursors under solvent-free or low-solvent conditions with equimolar or less chlorinating reagents. This high-yielding protocol allows successful preparations of multigram and kilogram batches of these important synthetic intermediates.