Substituted piperazinyl pyrazines and pyridines as 5-ht7 receptor antagonists

A compound of the formula:

• where:
• A is —C(H)═ or —N═,
• R1 is selected from the group consisting of phenyl optionally substituted with methoxy or 1 to 3 independently selected chloro or fluoro substituents;
• pyrazol-4-yl optionally substituted with 1 to 3 methyl or ethyl groups;
• imidazolyl optionally substituted with 1 or 2 C1-C3 methyl or ethyl;
• pyridyl optionally substituted with fluoro or chloro;
• and thienyl;
• R2 is hydrogen or methyl;
• m is 0, 1, or 2;
• R3 is selected from the group consisting of hydrogen, fluoro, chloro, hydroxy, methoxy, hydroxymethyl, cyanomethyl, methoxymethyl, acetyl, methylcarbonylamino, methylcarbonylaminomethyl, pyrazol-1-ylmethyl, and triazolylmethyl, provided that when R3 is hydrogen, m is not 0;
• each R4 is independently selected from the group consisting of fluoro, chloro, methyl, and methoxy;
• or alternatively, two R4 groups together with the phenyl to which they are attached join to form an indol-4-yl group;
• or a pharmaceutically acceptable salt thereof.