1,2,4-triazines in organic synthesis, Part 33.: S-Transalkylation/ring closing metathesis as a route to azathiamacrocycles incorporating 2,2′-bipyridine subunits

A new route to cyclophanes 6a,b incorporating 2,2'-bipyridine subunits has been elaborated using as the key steps (1) S-transalkylation of 6.6'-bis(methylsulfyl)-2,2'-bipyridines 2a,b with ethyl bromoacetate resulting in the formation of 6,6'-bis[(ethoxycarbonyl)methylsulfanyl]-2.2'-bipyridines 3a,b and (2) ring-closing metathesis of the corresponding alkenyl ethers 5a,b. (c) 2005 Elsevier Ltd. All rights reserved.