Heterocycle derivatives and drugs

A compound of the formula [I] or a salt thereof:

• A—B—D—E— [1]
• wherein
• A is a 5- or 6-membered heteroaryl group having one or two nitrogen atoms as ring-composing members or its oxide;
• B is an ethenylene group optionally substituted by cyano, bromo or C1—C6 alkyl;
• D is a phenylene group optionally substituted by hydroxyl, halogen, amino, C1—C6 alkyl or C1—C6 alkoxy;
• and
• E is a group of the formula:
• wherein G is a phenyl group optionally substituted by hydroxyl of C1—C6 alkoxy;
• and R is a 5- or 6-membered heteroaryl group having one or two nitrogen atoms as ring-composing members or a 5- or 6-membered heteroarylmethyl group having one or two nitrogen atoms as ring-composing members, or a group of the formula:
• wherein n is an integer of 1 to 5;
• R5 and R6 are the same or different and independently selected from the group consisting of hydrogen, C1—C6 alkyl, or R5 and R6 taken together with the adjacent nitrogen atom may form a 5- to 7-membered cyclic amino group for —NR5(R6) which may optionally be substituted by one or two substituents selected from the group consisting of alkyl, alkenyl, aryl, aralkyl, a 5- to 6-membered heteroaryl group having one to two nitrogen atoms and a 5- to 7-membered cyclic amino group.