1-(2-Phenoxyethyl)-lH-imidazole was found to be an inhibitor of thromboxane (TxA,) synthetase, but it also inhibited the adrenal cytochrome P-450 enzyme steroid ll@- hydroxylase. The preparation of a series of analogues is described, and activity against TxA2 synthetase, PG12 synthetase, cyclooxygenase, and steroid ll@-hydroxylase is discussed. Potency against TxA2 synthetase was increased by introduction of a carboxyl ...