Tetrazolone as an acid bioisostere: application to marketed drugs containing a carboxylic acid

= 64 nM). Compounds containing a tetrazolone group showed similar microsomal stability and plasma protein binding to marketed acid counterparts, while also reducing the value for clog P. Furthermore, compound 7 displayed an improved rat pharmacokinetic profile cf. telmisartan 6. Taken together, the results demonstrate that a tetrazolone group may serve as a bioisostere for a carboxylic acid.