Substituted piperazine compounds optionally containing a quinolyl moiety for treating multidrug resistance

A compound having a formula:

• or an optical isomer, diastereomer, enantiomer, or pharmaceutically-acceptable salt thereof, wherein:
• (a) A is A1;
• (b) A1 is a group having a formula:
• wherein:
• (i) each R1 is independently selected from the group consisting of a hydrogen atom, a hydroxyl group, a hydrocarbon group, a substituted hydrocarbon group, a heterogeneous group, a substituted heterogeneous group, a carbocyclic group, a substituted carbocyclic group, a heterocyclic group, a substituted heterocyclic group, an aromatic group, a substituted aromatic group, a heteroaromatic group, and a substituted heteroaromatic group;
• (ii) x is 1 to 10;
• (iii) R2 is selected from the group consisting of a substituted hydrocarbon group and a substituted heterogeneous group;
• (iv) D1 and D2 are each independently selected from the group consisting of —C(O)— and —NR3—, wherein R3 is selected from the group consisting of a hydrogen atom, a hydrocarbon group, a substituted hydrocarbon group, a heterogeneous group, a substituted heterogeneous group, a carbocyclic group, a substituted carbocyclic group, a heterocyclic group, a substituted heterocycle group, an aromatic group, a substituted aromatic group, a heteroaromatic group, and a substituted heteroaromatic group;
• wherein, optionally, R2 and R3 may be bonded together to form a ring selected from the group consisting of a heterocyclic group and a substituted heterocyclic group;
• (v) y is 0 or 1 and z is 0 or 1;
• with the provisos that when y is 0, z is 1 and when y is 1, z is 0, when y is 0 and D1 is —NR3—, then D2 is —C(O)—, when y is 0 and D2 is —NR3—, then D1 is —C(O)—;
• and
• (c) A2 is a group having a formula:
• wherein:
• (i) each R1 is independently selected from the group consisting of a hydrogen atom, a hydroxyl group, a hydrocarbon group, a substituted hydrocarbon group, a heterogeneous group, a substituted heterogeneous group, a carbocyclic group, a substituted carbocyclic group, a heterocyclic group, a substituted heterocyclic group, an aromatic group, a substituted aromatic group, a heteroaromatic group, and a substituted heteroaromatic group;
• (ii) u is 0 to 10;
• (iii) p is 0 to about 10;
• (iv) v is 0 or 1;
• (v) D3 is selected from the group consisting of —S(O)2—, —C(O)—, and CR1(OH)—, with the provisos that when D3 is —S(O)2—, then D1 is —C(O)—, D2 is —NR3—, and R2 and R3 are bonded together to form the ring structure, and when D3 is —C(O)—, v is 0, and R5 contains a —C(O)— group, then p is not 0;
• and
• (vi) R5 is selected from the group consisting of a hydrocarbon group, a substituted hydrocarbon group, a heterogeneous group, a substituted heterogeneous group, a carbocyclic group, a substituted carbocyclic group, a heterocyclic group, a substituted heterocyclic group, an aromatic group, a substituted aromatic group, a heteroaromatic group, and a substituted heteroaromatic group;
• wherein when A is A1 then R1 is a heteroaromatic group.