Abstract: Compounds of the formula (I) or pharmaceutically acceptable salts thereof ##STR1## where R.sub.2 -R.sub.7, Y, a and b are as defined, are useful in the treatment of hypertension and respiratory tract disorders.

Abstract: Compounds of formula (I) and pharmaceutically acceptable salts thereof: ##STR1## wherein a, b, J, Y and R.sub.2 -R.sub.8 are as defined herein are potassium channel activators, a process for their preparation and their pharmaceutical use.

Abstract: A compound of formula (I) or a pharmaceutically acceptable salt thereof: ##STR1## wherein a and b together form an --O-- or --CH.sub.2 -- linkage or a bond;either Y is N and R.sub.2 is hydrogen; orY is C-R.sub.1whereineither one of R.sub.1 and R.sub.2 is hydrogen and the other is nitro, cyano, halo, --CF.sub.3, C.sub.2 F.sub.5, formyl aldoxime, CF.sub.3 O, NO.sub.2 --CH.dbd.CH--, NC--CH.dbd.CH--; a group R.sub.x X-- wherein R.sub.x is C.sub.1-6 alkyl, aryl or heteroaryl either of which may be optionally substituted by one, two or three of C.sub.1-4 alkyl, C.sub.1-4 alkoxy, nitro, halo, CF.sub.3 and cyano; and X is C.dbd.O, O.C.dbd.O, C.dbd.O.O, CHOH, SO, SO.sub.2, O.SO, O.SO.sub.2, CONH, O.CONH, C.dbd.S, O.C.dbd.S, C.dbd.S.O, CH.SH, SONH, SO.sub.2 NH, O.SONH, O.SO.sub.2 NH, CO--CH.dbd.CH, C.dbd.NHOH, C.dbd.NNH.sub.2 ; or a group R.sub.y R.sub.z NZ-- wherein R.sub.y and R.sub.z are independently hydrogen or C.sub.1-6 alkyl and Z is C.dbd.O, SO or SO.sub.2 ; or a group (R.sub.w O).sub.2 P(O)W wherein R.sub.

Abstract: Compounds of formula (I) and pharmaceutically acceptable salts thereof: ##STR1## wherein a and b together form an --O-- or --CH.sub.2 -- linkage or a bond;either Y is N and R.sub.2 is hydrogen; orY is C-R.sub.1whereineither one of R.sub.1 and R.sub.2 is hydrogen and the other is nitro, cyano, halo, CF.sub.3, formyl, aldoxime, CF.sub.3 O, NO.sub.2 --CH.dbd.CH--, NC--CH.dbd.CH--; a group R.sub.x X-- wherein R.sub.x and C.sub.1-6 alkyl, aryl or heteroaryl either of which may be optionally substituted by one, two or three of C.sub.1-4 alkyl, C.sub.1-4 alkoxy, nitro, halo, CF.sub.3 and cyano; and X is C.dbd.O, O.C.dbd.O, C.dbd.0.0, CHOH, SO, SO.sub.2, 0.SO, 0.SO.sub.2, CONH, 0.CONH, C.dbd.S, 0.C.dbd.S, C.dbd.S.0, CH.SH, SONH, SO.sub.2 NH, 0.SONH, 0.SO.sub.2 NH, CO--CH.dbd.CH, C.dbd.NHOH, C.dbd.NNH.sub.2 ; or a group R.sub.y R.sub.z NZ-- wherein R.sub.y and R.sub.z are independently hydrogen or C.sub.1-6 alkyl and Z is C.dbd.O, SO or SO.sub.2 ; orR.sub.1 is a C.sub.3-8 cycloalkyl group or a C.sub.

Abstract: Compounds of formula (I), or a pharmaceutically acceptable salt, quaternized derivative, N-oxide or solvate thereof:R.sub.1 --Ar--(CH.sub.2).sub.a --X--(CH.sub.2).sub.b --NH--Het (I)wherein: the substituents are defined in the specification.The compounds are useful in treating excess gastric acid secretions such as peptic ulcers.