Synthesis and biological investigations of 1-(tetrahydropyran-2′-yl)- and 1-(tetrahydrofuran-2′-yl)benzimidazoles and 1/2-(tetrahydropyran-2′-yl)- and 1/2-(tetrahydrofuran-2′-yl)benzotriazoles

Sets of benzimidazole and benzotriazole derivatives bearing on position 1 or 2 a tetrahydrofuranyl or tetrahydropyranyl moieties were prepared through the addition of the suitable benzazoles on 2,3-dihydrofuran and 3,4-dihydro-2H-pyran. The reactions were carried on either without solvent or in carbon tetrachloride solution. In the last case some peculiar chlorinated side products were isolated and characterized. Twenty compounds were screened for in vitro antitumoral and anti-HIV-1 activities and found poorly active or completely inactive. On the other hand several compounds exhibited good tracheal relaxant activity in vitro; compound 8, 11, 16, 24 and 26 resulted more active than theophylline in this test, while compound 11 was comparable to amrinone till the concentration of 3 pg/ml. Finally, compound 5 resulted endowed with a strong diuretic and saluretic activity at the dose of 3 mg/Kg, thus representing a new lead for discovering new diuretic agents.