The novel benzopyran class of selective cyclooxygenase-2 inhibitors. Part 2: The second clinical candidate having a shorter and favorable human half-life

In this Letter, we provide the structure-activity relationships, optimization of design, testing criteria, and human half-life data for a series of selective COX-2 inhibitors. During the course of our structure-based drug design efforts, we discovered two distinct binding modes within the COX-2 active site for differently substituted members of this class. The challenge of a undesirably long human half-life for the first clinical candidate 1 t(1/2) = 360 h was addressed by multiple strategies, leading to the discovery of 29b-(S) (SC-75416) with t(1/2) = 34 h. (C) 2010 Elsevier Ltd. All rights reserved.