Triazolopyridines 23. Synthesis of 5,5'-bi[1,2,3]triazolo[5,1-a]isoquinoline

5,5'-Bi[1,2,3]triazolo[5,1-a]isoquinoline 6 has been synthesised from [1,2,3]triazolo[5,1-a] isoquinoline 5 by four procedures, dimerisation by LDA, Stille and Suzuki self-coupling reactions, and Suzuki cross-coupling reaction. The last is the best. Compound 6 gives 1,1'bi(acetoxymethyl)-3,3'-biisoquinoline 10 by triazolo ring opening by acetic acid.