Piperazine derivatives and methods of use

A method for treating infertility in a mammal, comprising administering to a mammal suspected of infertility a therapeutically effective amount of a compound of Formula I:

• wherein R1 and R2 are independently selected from the group comprising or consisting of hydrogen, C1-C12-alkyl, C2-C12-alkenyl, C2-C12-alkynyl, wherein said alkyl, alkenyl, alkynyl chains may be interrupted by a heteroatom selected from N, O or S, aryl, heteroaryl, saturated or unsaturated 3-8-membered cycloalkyl, heterocycloalkyl, wherein said cycloalkyl, heterocycloalkyl, aryl or heteroaryl groups may be fused with 1-2 further cycloalkyl, heterocycloalkyl, aryl or heteroaryl group, an acyl moiety, C1-C12-alkyl aryl, C1-C12-alkyl heteroaryl, C2-C12-alkenyl aryl, C2-C12-alkenyl heteroaryl, C2-C12-alkynyl aryl, C2-C12-alkynyl heteroaryl, C1-C12-alkyl cycloalkyl, C1-C12-alkyl heterocycloalkyl, C2-C12-alkenyl cycloalkyl, C2-C12-alkenyl heterocycloalkyl, C2-C12-alkynyl cycloalkyl, C2-C12-alkynyl heterocycloalkyl, alkoxycarbonyl, aminocarbonyl, C1-C12-alkyl carboxy, alkyl acyl, aryl acyl, heteroaryl acyl, C3-C8-(hetero)cycloalkyl acyl, C1-C12-alkyl acyloxy, C1-C12-alkyl alkoxy, C1-C12-alkyl alkoxycarbonyl, C1-C12-alkyl aminocarbonyl, C1-C12-alkyl acylamino, acylamino, C1-C12-alkyl ureido, C1-C12-alkyl carbamate, C1-C12-alkyl amino, C1-C12-alkyl ammonium, C1-C12-alkyl sulfonyloxy, C1-C12-alkyl sulfonyl, C1-C12-alkyl sulfinyl, C1-C12-alkyl sulfanyl, C1-C12-alkyl sulfonylamino, or C1-C12-alkyl aminosulfonyl;
• R3 is C1-C16-alkyl, C2-C16-alkenyl, C2-C16-alkynyl, wherein said alkyl, alkenyl, alkynyl chains may be interrupted by a heteroatom selected from N, O or S, aryl, heteroaryl, saturated or unsaturated 3-8-membered cycloalkyl, heterocycloalkyl, wherein said cycloalkyl, heterocycloalkyl, aryl or heteroaryl groups may be fused with 1-2 further cycloalkyl, heterocycloalkyl, aryl or heteroaryl group, an acyl moiety, C1-C16-alkyl aryl, C1-C16-alkyl heteroaryl, C2-C16-alkenyl aryl, C2-C16-alkenyl heteroaryl, C2-C16-alkynyl aryl, C2-C16-alkynyl heteroaryl, C1-C16-alkyl cycloalkyl, C1-C16-alkyl heterocycloalkyl, C2-C16-alkenyl cycloalkyl, C2-C16-alkenyl heterocycloalkyl, C2-C16-alkynyl cycloalkyl, C2-C16-alkynyl heterocycloalkyl, alkoxycarbonyl, aminocarbonyl, C1-C16-alkyl carboxy, C1-C16-alkyl acyl, aryl acyl, heteroaryl acyl, C3-C8-(hetero)cycloalkyl acyl, C1-C16-alkyl acyloxy, C1-C16-alkyl alkoxy, C1-C16-alkyl alkoxycarbonyl, C1-C16-alkyl aminocarbonyl, C1-C16-alkyl acylamino, acylamino, C1-C16-alkyl ureido, C1-C16-alkyl carbamate, C1-C16-alkyl amino, C1-C16-alkyl ammonium, C1-C16-alkyl sulfonyloxy, C1-C16-alkyl sulfonyl, C1-C16-alkyl sulfinyl, C1-C16-alkyl sulfanyl, C1-C16-alkyl sulfonylamino, or C1-C16-alkyl aminosulfonyl;
• R4 is C1-C12-alkyl, C2-C12-alkenyl, C2-C12-alkynyl, wherein said alkyl, alkenyl, alkynyl chains may be interrupted by a heteroatom selected from N, O or S, aryl, heteroaryl, saturated or unsaturated 3-8-membered cycloalkyl, heterocycloalkyl, wherein said cycloalkyl, heterocycloalkyl, aryl or heteroaryl groups may be fused with 1-2 further cycloalkyl, heterocycloalkyl, aryl or heteroaryl group, or amino;
• and pharmaceutically acceptable salts thereof.