The addition reaction of lithiumreagents to the 4 position of 2‐chloropyrimidine or 2‐chloroquinazoline followed by oxidation of the resultant dihydro intermediate product is a powerful tool for the synthesis of 4‐substituted 2‐chloropyrimidines or 2‐chloroquinazolines. 4‐Vinyl derivatives undergo a conjugate nucleophilic addition across the vinyl group. A nucleophilic displacement of chloride in