Synthesis of 1,3-Diynes in the Purine, Pyrimidine, 1,3,5-Triazine and Acridine Series

A range of conjugated 1,3-diynes, R1CCCCR2, has been prepared that incorporate the following heteroaromatic units as head groups of the substituents R1 and/or R2: pyrimidinyl, purinyl, 2,4-diamino-1,3,5-triazinyl and acridinyl. Compounds containing the first three groups as terminal heterocyclic substituents in both R1 and R2 are bonded through methylene linkers {(CH2)n, n=1, 4 or 9} to the 1,3-diyne; also reported are amphiphilic species with R2=n-C10H21 and a single heteroaromatic head group in chain R1. Compounds in the acridine series are also amphiphiles and contain quaternised 1′-(9-acridinylamino)- and 1′-(6-chloro-2-methoxyacridinylamino)- terminal substituents linked by PEG and methylene units to the diyne function. The new diynes have been synthesised by oxidative coupling of the corresponding ω-heteroaromatic functionalised 1-alkyne or by transformation of terminal groups on preformed diynes.