Unique chlorine effect in regioselective one-pot synthesis of 1-alkyl-/allyl-3-(o-chlorobenzyl) uracils: anti-HIV activity of selected uracil derivatives

2,4-Bis(trimethylsiloxy)pyrimidines on reaction with alkyl-/allyl-/benzyl halides, followed by the subsequent addition of o-chlorobenzyl chlorides, provide a one-pot synthesis of 1,3-unsymmetrical alkylated pyrimidine-2,4-diones.