TrkA kinase inhibitors from a library of modified and isosteric Staurosporine aglycone.

An immobilized Staurosporine aglycone isostere where one of the indole nitrogen atoms was replaced by carbon has been sequentially functionalized to generate compounds inhibiting TrkA kinase. In the first phase, initial screening of a library of C13-hydroxymethyl-7-oxo-indenopyrrolocarbazoles resulted in several potent compounds, one of which was further optimized to generate the corresponding carbamates on solid phase. Some of the major carbamate diastereomers were found to be several-fold more potent than their alcohol parents. Synthesis, SAR analysis, kinase selectivity, and anti-tumor properties of a TrkA inhibitor (12a) are discussed.