6-Amino-2,4,5-trimethylpyridin-3-ols: A new general synthetic route and antiangiogenic activity

•A general synthetic strategy for 6-amino-2,4,5-trimethylpyridin-3-ols was developed.•A wider range of aminopyridinols can be prepared by the new synthetic strategy.•Some aminopyridinols show high level of antiangiogenic activities in CAM assay.

A new synthetic strategy for preparation of a wide range of 6-amino-2,4,5-trimethylpyridin-3-ols from pyridoxine·HCl via a six-step sequence has been developed. This approach features an introduction of various amino groups to C(6)-position of 3-benzyloxy-6-bromo-2,4,5-trimethylpyridine (13), a key intermediate, by a Buchwald–Hartwig amination reaction using palladium(0) transition metal, which certainly renders an expanded scope of amino substituents. Some analogs prepared using the methods described here showed high level of antiangiogenic and antitumor activities in chick chorioallantoic membrane (CAM) assay, demonstrating the potential of these new aminopyridinols as antiangiogenic agents.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide