Piperazines combinatorial library

Solution-phase combinatorial chemistry overcomes the restrictions of solid-phase synthesis caused by the need to attach educts to, and release products from, the solid support. The adaptation of standard synthesis procedures to solid-phase chemistry is not necessary. On the other hand, the chemist must be careful to ensure that educts have reacted almost completely, and that excess reagents are removed after each reaction step this represents a challenge for automation and process control. A core molecule as a template with several reactive groups has been used to generate xanthenene [30] or piperazine [31] libraries, for example. An iterative process for identification can be carried out by the deletion of one of the building blocks. 

Triazole-substituted piperazine amides mimicking )8-tum stractures were reported by the Burgess group. Fifteen piperazine amides were prepared and isolated in high yields (23, 71-96%, Scheme 10.7) and used in couplings with dichlorotriazine derivatives (tagged with fluorescein or an alkyne) to afford combinatorial libraries 24, which were... 

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