Polymer-assisted solution-phase library synthesis of 4-alkoxy-2-hydroxy-3,5,6-trifluorobenzoic acids

The efficient synthesis of a small library of 4-alkoxy-2-hydroxy-3,5,6-trifluorobenzoic acids is described via the fluoride mediated alkylation of 5,6,8-trifluoro-7-hydroxy-2-methyl-benzo[1,3]dioxin-4-one with a collection of structurally diverse bromoalkanes. The use of ion-exchange resins during the reaction sequence enabled the preparation of the majority of the products in 82–98% purity without the need for chromatography.