4-Metalated Condensed Pyrimidines: Their Preparation and Reaction with Aldehydes under Barbier-Type Conditions

The organometallic intermediate obtained from halogen−metal exchanges of 4-iodo-6-phenylthieno[2,3-d]pyrimidine under Barbier-type conditions
was reacted with aldehydes to form the corresponding alcohols in moderate yields. The reaction involving an organolithium intermediate
proceeded only at low temperature, whereas the reaction involving a magnesium ate intermediate also proceeded at room temperature. A
crystal structure confirms that the expected constitutional alcohol isomer is formed, where no migration has taken place. The conditions were
also suitable for 9-benzyl-6-iodopurine.