Cyclobutoxy spacer

We were interested in exploring the replacement of the propoxy linker with a cyclobutoxy spacer, the latter presenting the advantage of being the most compact cyclic constraint still incorporating the three-carbon spacer. This work was done in collaboration with Amsterdam University [51]. 

Table 18.6 Affinities and activities of compounds with a propoxy or a cyclobutoxy spacer.

We decided to take a step back and revisit some previous series with the objective to simplify the right-hand side of the molecule (fused thiazoles) and capitalize on the benefits offered by the cyclobutoxy spacer. 

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