Tricyclic dihydropyrimidine potassium channel openers

A compound having formula I:

• or a pharmaceutically acceptable salt thereof wherein,
• n is an integer 0-1;
• m is an integer 1-2;
• provided that when m is 2, n is 0;
• R1 is selected from the group consisting of aryl and heterocycle;
• Q is selected from the group consisting of C(O), S(O), and S((O)2;
• V is selected from the group consisting of C(R6)(R7), O, S, and NR2, wherein R2 is selected from the group consisting of hydrogen, alkenyl, alkoxy, alkoxyalkoxy, alkoxyalkyl, alkyl, alkynyl, aryl, arylalkoxy, arylalkenyl, arylalkyl, cyano, cycloalkyl, cycloalkylalkyl, haloalkoxy, haloalkyl, heterocycle, heterocyclealkyl, hydroxy, hydroxyalkyl, —NR4R5, and (NR4R5)alkyl wherein R4 and R5 are independently selected from the group consisting of hydrogen and lower alkyl;
• R6 and R7 are independently selected from the group consisting of hydrogen, alkenyl, alkoxy, alkoxyalkoxy, alkoxyalkyl, alkyl, alkylthio, alkynyl, aryl, arylalkoxy, arylalkenyl, arylalkyl, carboxy, cyano, cycloalkyl, cycloalkylalkyl, haloalkoxy, haloalkyl, halogen, heterocycle, heterocyclealkyl, hydroxy, hydroxyalkyl, oxo, —NR4R5, and (NR4R5)alkyl;
• X is selected from the group consisting of N and CR3, wherein R3 is selected from the group consisting of hydrogen, alkenyl, alkoxy, alkoxyalkoxy, alkoxyalkyl, alkyl, alkylthio, alkynyl, aryl, arylalkoxy, arylalkenyl, arylalkyl, carboxy, cyano, cycloalkyl, cycloalkylalkyl, haloalkoxy, haloalkyl, halogen, heterocycle, heterocyclealkyl, hydroxy, hydroxyalkyl, —NR4R5, and (NR4R5)alkyl;
• A and B are independently selected from the group consisting of hydrogen, alkenyl, alkoxy, alkoxyalkoxy, alkoxyalkyl, alkyl, alkylthio, alkynyl, aryl, arylalkoxy, arylalkenyl, arylalkyl, carboxy, cyano, cycloalkyl, cycloalkylalkyl, haloalkoxy, haloalkyl, halogen, heterocycle, heterocyclealkyl, hydroxy, hydroxyalkyl, —NR4R5, and (NR4R5)alkyl;
• and
• D and E are independently selected from the group consisting of hydrogen, alkenyl, alkoxy, alkoxyalkoxy, alkoxyalkyl, alkyl, alkylthio, alkynyl, aryl, arylalkoxy, arylalkenyl, arylalkyl, carboxy, cyano, cycloalkyl, cycloalkylalkyl, haloalkoxy, haloalkyl, halogen, heterocycle, heterocyclealkyl, hydroxy, hydroxyalkyl, oxo, —NR4R5, and (NR4R5)alkyl.