[2.2](2,5)Pyrimidinophanes: Synthesis and molecular structure

Abstract

Abstract The title compounds 1 and 2 are synthesized by photolytic sulfur extrusion from the 2,11‐dithia[3.3](2,5)pyrimidinophane 17 . The molecular structures of 1 and 2 are determined by X‐ray structure analysis and are discussed with regard to the steric strain in these molecules. Thermolysis of [(5‐methyl‐2‐pyrimidinyl]methyl]‐ or [(2‐methyl‐5‐pyrimidinyl)methyl]‐trimethylammonium hydroxide ( 10 or 11 ) does not generate 1 and 2 . α‐Chlorination of 2,5‐dimethylpyrimidine ( 3 ) with N ‐chlorosuccinimide provides the required precursors 4 – 6 .