Benzopyran compounds.

摘要

Compounds of formula (I), and pharmaceutically acceptable salt thereof: <CHEM> wherein a and b together form an -O- linkage or a bond or (when R2 is hydrogen), CH2; either Y is N and R2 is hydrogen; or Y is C-R1 wherein either one of R1 and R2 is hydrogen and the other is nitro, cyano, halo, CF3, C2F5, formyl, aldoxime, CF3O, NO2-CH=CH-, NC-CH=CH-; a group RxX- wherein Rx is C1-6 alkyl, aryl or heteroaryl either of which may be optionally substituted by one, two or three of C1-4 alkyl, C1-4 alkoxy, nitro, halo, CF3 and cyano; and X is CO, O.C=0, C=O.O, CHOH, SO, SO2, O.SO, O.SO2, CONH, O.CONH, C=S, O.C=S, C=S.O, CH.SH, SONH, SO2NH, O.SONH, 0.SO2NH, CO-CH=CH, C=NHOH, C=NNH2; or a group RyRzNZ where Ry and Rz are independently hydrogen or C1-6 alkyl and Z is C=O, SO or SO2; or a group (RwO)2P(O)W wherein Rw is hydrogen or C1-6 alkyl and W is O or a bond; or R1 is a C3-8 cycloalkyl group or a C1-6 alkyl group optionally substituted by a group which is hydroxy, C1-6 alkoxy, amino optionally substituted by one or two C1-6 alkyl groups, C1-7 alkanoylamino, C3-8 cycloalkyloxy or C3-8 cycloalkylamino; and R2 is hydrogen; or one of R1 and R2 is nitro, cyano or C1-3 alkylcarbonyl and the other is a different group selected from nitro, cyano, halo, C1-3 alkylcarbonyl, methoxy or amino optionally substituted by one or two C1-6 alkyl or by C2-7 alkanoyl; or R1 and R2 together with the carbon atoms to which they are attached, form 2,1,3-oxadiazole or triazole; either one of R3 and R4 is hydrogen or C1-4 alkyl and the other is C1-4 alkyl; or R3 and R4 together are C2-5 polymethylene; either R5 is hydrogen, hydroxy, C1-6 alkoxy or C1-7 acyloxy or ONO2; and R6 is hydrogen; or R5 and R6 together are a bond; R7 is optionally substituted phenyl; and the pyridonyl moiety is trans to the R5 group when R5 is hydroxy, C1-6 alkoxy, C1-7 acyloxy or ONO2; which are potassium channel activators, a process for their preparation and their use as pharmaceuticals.