Selective synthesis of functionalized thia- and oxacalix[2]arene[2] pyrimidines

Functionalized oxacalix[m]arene[n]pyrimidines have been synthesized by SNAr on 4,6-dihalopyrimidine building blocks. Depending on the SNAr conditions, either a mixture of oxacalix[n]arenes, ranging from oxacalix[4]- up to oxacalix[12] arene, could be prepared or the oxacalix[4]arene could be synthesized selectively in a high yield. The electrophilic (pyrimidine) and the nucleophilic components could both be varied, allowing the preparation of functionalized oxacalix[4]arenes. Moreover, the procedure also gives access to the analogous thiacalix[4]arenes.