Synthesis of 5-hydroxy-4-nitrosobenzotriazoles and 6-hydroxy-7-nitrosoindazoles and their splitting into ?-triazolyl- and ?-pyrazolylacrylic acids

Solid-Supported Benzotriazoles: Synthetic Auxiliaries and Traceless Linkers for the Combinatorial Synthesis of Amine Libraries

“…The connection between the polymer and the heterocycle was examined because often harsh reducing agents or organometallic reagents such as Grignard reagents are used during the synthesis. Two strategies were followed and are reported in Scheme , top: the preparation of 5-hydroxy benzotriazole, according to literature procedures, followed by the N -Boc protection to afford compound 9a with a moderate overall yield. Coupling of the phenolic function of 9a with the resin was planned to anchor the compound via a stable ether bond.…”