Antiallergic agents. 2. N-(1H-tetrazol-5-yl)-6-phenyl-2-pyridinecarboxamides

A new series of N-(1H-tetrazol-5-yl)-6-phenyl-2-pyridinecarboxamides was prepared to determine the effects of substituents on the benzene and pyridine rings on antiallergic activity in the rat passive cutaneous anaphylaxis (PCA) assay after oral administration. One member of this series, N-(1H-tetrazol-5-yl)-4-methyl-6-[4-(methylamino)-phenyl]-2- pyridinecarboxamide (231), has an ED50 value of 0.8 mg/kg po and is 85 times more potent than disodium cromoglycate (DSCG) on intravenous administration. Further evaluation of 231 as a clinically useful antiallergic agent is in progress.