NK-3 receptor selective antagonist compounds, pharmaceutical composition and methods for use in NK-3 receptors mediated disorders

Abstract

The present invention is directed to novel compounds of formula I ##STR00001##
and their use as therapeutic compounds.

Claims

1. A pharmaceutical composition comprising a compound of formula I: ##STR00062## or a pharmaceutically acceptable salt or solvate thereof and at least one pharmaceutically acceptable carrier, diluent, excipient and/or adjuvant, wherein Ar.sup.1 is a 5- to 6-membered aryl or heteroaryl group, 3- to 6-membered cycloalkyl group, a 3- to 6-membered heterocyclyl group or a C3-C6 alkyl group, each of the aryl, heteroaryl, cycloalkyl or heterocyclyl groups being optionally substituted by one or more group(s) selected from halo, cyano, alkyl, haloalkyl, cycloalkyl, heteroalkyl, heterocyclyl, aryl, aralkyl, heteroaryl, hydroxyl, alkoxy, haloalkoxy, alkoxyalkoxy, alkylamino, carboxy, alkoxycarbonyl, alkylcarbonyloxy, alkylcarbonylamino, haloalkylcarbonylamino, carbamoyl, alkylcarbamoyl, carbamoylamino, alkylcarbamoylamino, alkylsulfonyl, haloalkylsulfonyl, sulfamoyl, alkylsulfamoyl, alkylsulfonylamino, haloalkylsulfonylamino, or two substituents form an alkylenedioxy group or a haloalkylenedioxy group, or two substituents form a cycloalkyl or heterocycloalkyl moiety together with the cycloalkyl or heterocycloalkyl group they are attached to, or fused to the aryl, heteroaryl, cycloalkyl or heterocycloalkyl group may be one or more aryl moiety, each of said substituents being optionally substituted by one or more further substituent(s) selected from halo, cyano, alkyl, haloalkyl, cyclopropyl, alkoxy, haloalkoxy, heterocyclyl, aryl, heteroaryl, aryloxy heteroaryloxy; L.sup.1 is C.sub.1-C.sub.2 alkylene optionally being substituted by one or more group(s) selected from halo, methyl or ethyl under the condition that R.sup.2 together with R.sup.2 form an oxo substituent, or L.sup.1 is carbonyl or sulfonyl, or L.sup.1 is (CO)CH.sub.2 where the CO is linked to the piperazine nitrogen and the CH.sub.2 to Ar.sup.1; R.sup.1 is H, a C.sub.1-C.sub.4 alkyl, aryl or aralkyl group, each of said alkyl, aryl or aralkyl groups being optionally substituted by one or more group(s) selected from halo or hydroxyl; R.sup.1 is H or a C.sub.1-C.sub.4 alkyl group; R.sup.2 is H or a C.sub.1-C.sub.4 alkyl group; R.sup.2 is H or a C.sub.1-C.sub.4 alkyl group, or, when L.sup.1 is C.sub.1-C.sub.2 alkylene optionally being substituted by one or more group(s) selected from halo, methyl or ethyl, R.sup.2 together with R.sup.2 form an oxo substituent; R.sup.3 is H or a C.sub.1-C.sub.4 alkyl group optionally substituted by one hydroxy; R.sup.3 is H or a C.sub.1-C.sub.4 alkyl group; X.sup.1 and X.sup.2 are independently N; L.sup.2 is a single bond or carbonyl, Ar.sup.2 is a 5- to 6-membered aryl or heteroaryl group, each of the aryl, or heteroaryl groups being optionally substituted by one or more group(s) selected from halo, cyano, alkyl, hydroxyalkyl, haloalkyl, cycloalkyl, heteroalkyl, heterocyclyl, aryl, heteroaryl, aralkyl, heteroarylalkyl, hydroxyl, alkoxy, haloalkoxy, alkylamino, carboxy, alkoxycarbonyl, alkylcarbonyloxy, alkylcarbonylamino, haloalkylcarbonylamino, acylamino, carbamoyl, alkylcarbamoyl, carbamoylalkyl, carbamoylamino, alkylcarbamoylamino, alkylsulfonyl, haloalkylsulfonyl, arylsulfonylalkyl, sulfamoyl, alkylsulfamoyl, alkylsulfonylamino, haloalkylsulfonylamino, or two substituents form an alkylenedioxy group or a haloalkylenedioxy group, or fused to the aryl or heteroaryl group may be one or more cycloalkyl, aryl, heterocyclyl or heteroaryl moiety, each of said substituents being optionally substituted by one or more further substituent(s) selected from halo, cyano, alkyl, haloalkyl, alkoxy, haloalkoxy, cycloalkyl, heterocyclyl optionally substituted by alkyl, aryl, heteroaryl, hydroxyl, alkoxyalkyl, hydroxyalkoxy, alkylamino, alkylsulfonylamino, alkoxycarbonylamino, aminoalkoxy, or alkoxycarbonylaminoalkoxy; and wherein, when: R.sup.1, R.sup.1, R.sup.2, R.sup.2, R.sup.3, R.sup.3 are H, and L.sup.1 is carbonyl, and L.sup.2 is single bond, and Ar.sup.1 is a 6-membered aryl optionally substituted by one or more group(s) selected from halo, cyano, C1-C3 alkyl, C1 haloalkyl, and Ar.sup.2 is a 5- to 6-membered aryl or heteroaryl group optionally substituted by one or more group(s) selected from halo, C1-C3 alkyl, hydroxyl, methoxy, or fused to an aryl or heteroaryl group optionally substituted by one or more further halo, C1-C3 alkyl, hydroxyl, methoxy, then, Ar.sup.1 is phenyl, 3-halophenyl, 4-halophenyl, 2,3-dichlorophenyl, 2,4-difluorophenyl, 2,4-dichlorophenyl, 2,5-dihalophenyl, 2,6-difluorophenyl, 2,6-dichlorophenyl, 3,4-dihalophenyl, 3,5-dihalophenyl, 3,4,5-trihalophenyl, 2-cyanophenyl, 3-cyanophenyl, 4-cyanophenyl, 2,3-dicyanophenyl, 2,4-dicyanophenyl, 3,5-dicyanophenyl, 3-cyano-4-halophenyl, 4-(C1-C3 alkyl)phenyl, 3,4-di(C1-C3 alkyl)phenyl, 3,5-di(C1-C3 alkyl)phenyl, 4-(C1 haloalkyl)phenyl, and Ar.sup.2 is, quinolin-2-yl, isoquinolin-3-yl, 8-haloquinolin-2-yl, benzothiazol-2-yl, 4,5,6,7-tetrahydro-1,3-benzothiazol-2-yl; with the following provisos: Ar.sup.1 is neither a substituted or unsubstituted pyrazolo[1,5-a]pyridin-2yl nor a substituted or unsubstituted pyrazolo[1,5-a]pyrimidin-2yl moiety.

2. The pharmaceutical composition according to claim 1 comprising a compound of formula Ib ##STR00063## or a pharmaceutically acceptable salt or solvate thereof and at least one pharmaceutically acceptable carrier, diluent, excipient and/or adjuvant.

3. The pharmaceutical composition according to claim 2 comprising a compound of formula Ic ##STR00064## or a pharmaceutically acceptable salt or solvate thereof and at least one pharmaceutically acceptable carrier, diluent, excipient and/or adjuvant, wherein a depicts the bond linking R.sup.1 to the piperazine moiety.

4. The pharmaceutical composition according to claim 3 comprising a compound selected from formulae Id-1, Id-2, Id-3 and Id-4 ##STR00065## or a pharmaceutically acceptable salt or solvate thereof and at least one pharmaceutically acceptable carrier, diluent, excipient and/or adjuvant, wherein a depicts the bond linking R.sup.1 to the piperazine moiety; and R.sup.4, R.sup.4, R.sup.5, R.sup.5 and R.sup.6 are independently selected from H, halo, cyano, alkyl, haloalkyl, C3-C6 cycloalkyl, heteroalkyl, heterocyclyl, aryl, heteroaryl, hydroxyl, alkoxy, haloalkoxy, alkoxyalkoxy, alkylamino, carboxy, alkoxycarbonyl, alkylcarbonyloxy, alkylcarbonylamino, haloalkylcarbonylamino, carbamoyl, alkylcarbamoyl, carbamoylamino, alkylcarbamoylamino, alkylsulfonyl, haloalkylsulfonyl, sulfamoyl, alkylsulfamoyl, alkylsulfonylamino, haloalkylsulfonylamino, or R.sup.5 together with R.sup.4 or R.sup.6, or R.sup.5 together with R.sup.4 or R.sup.6 forms an alkylenedioxy group or a haloalkylenedioxy group, or R.sup.5 together with R.sup.4 or R.sup.6, or R.sup.5 together with R.sup.4 or R.sup.6 forms an aryl moiety fused to the phenyl group to which they are attached, each of said substituents being optionally substituted by one or more further substituent(s) selected from halo, cyano, alkyl, haloalkyl, cyclopropyl; and R.sup.7 is H or methyl; and R.sup.7 is H or methyl; and Ar.sup.4 is a cycloalkyl or an aryl group, each of said cycloalkyl or aryl groups being optionally substituted by one or more group(s) selected from halo, alkyl, haloalkyl, cyclopropyl, haloalkoxy, aryloxy; and M.sup.1 is N or CR.sup.4 wherein R.sup.4 is selected from H, halo, cyano, alkyl, haloalkyl, C3-C6 cycloalkyl, heteroalkyl, heterocyclyl, aryl, heteroaryl, hydroxyl, alkoxy, haloalkoxy, alkoxyalkoxy, alkylamino, carboxy, alkoxycarbonyl, alkylcarbonyloxy, alkylcarbonylamino, haloalkylcarbonylamino, carbamoyl, alkylcarbamoyl, carbamoylamino, alkylcarbamoylamino, alkylsulfonyl, haloalkylsulfonyl, sulfamoyl, alkylsulfamoyl, alkylsulfonylamino, haloalkylsulfonylamino, each of said substituents being optionally substituted by one or more further substituent(s) selected from halo, cyano, alkyl, haloalkyl, cyclopropyl; and M.sup.2 is N or M.sup.2 is CR.sup.5 under the condition that M.sup.1 is N, wherein R.sup.5 is selected from H, halo, cyano, alkyl, haloalkyl, C3-C6 cycloalkyl, heteroalkyl, heterocyclyl, aryl, heteroaryl, hydroxyl, alkoxy, haloalkoxy, alkoxyalkoxy, alkylamino, carboxy, alkoxycarbonyl, alkylcarbonyloxy, alkylcarbonylamino, haloalkylcarbonylamino, carbamoyl, alkylcarbamoyl, carbamoylamino, alkylcarbamoylamino, alkylsulfonyl, haloalkylsulfonyl, sulfamoyl, alkylsulfamoyl, alkylsulfonylamino, haloalkylsulfonylamino, or R.sup.5 together with R.sup.6 forms an alkylenedioxy group or a haloalkylenedioxy group, or an aryl moiety fused to the pyridinyl group to which they are attached, each of said substituents being optionally substituted by one or more further substituent(s) selected from halo, cyano, alkyl, haloalkyl, cyclopropyl; and wherein, in formula Id-1 when: R.sup.1 is H, and R.sup.4, R.sup.4, R.sup.5, R.sup.5 and R.sup.6 are independently selected from H, halo, cyano, C1-C3 alkyl, C1 haloalkyl, and Ar.sup.2 is a 5- to 6-membered aryl or heteroaryl group optionally substituted by one or more group(s) selected from halo, C1-C3 alkyl, hydroxyl, alkoxy, or fused to an aryl group optionally substituted by one or more further halo, C1-C3 alkyl, hydroxyl, methoxy then, R.sup.4, R.sup.4, R.sup.5, R.sup.5 and R.sup.6 are H, or R.sup.4, R.sup.4, R.sup.5, R.sup.6 are H and R.sup.5 is halo, or R.sup.4, R.sup.4, R.sup.5, R.sup.5 are H and R.sup.6 is halo, cyano, C1-C3 alkyl, C1 haloalkyl, or R.sup.4, R.sup.5, R.sup.6 are H and R.sup.4, R.sup.5 are halo, or R.sup.4, R.sup.4, R.sup.5 are H and R.sup.5, R.sup.6 are independently halo, or R.sup.4, R.sup.4 are H and R.sup.5, R.sup.5, R.sup.6 are halo, and Ar.sup.2 is, quinolin-2-yl, isoquinolin-3-yl, 8-haloquinolin-2-yl, benzothiazol-2-yl, 4,5,6,7-tetrahydro-1,3-benzothiazol-2-yl.

5. The pharmaceutical composition according to claim 4 comprising a compound selected from formulae Ie-1, Ie-2 and Ie-3 ##STR00066## or a pharmaceutically acceptable salt or solvate thereof and at least one pharmaceutically acceptable carrier, diluent, excipient and/or adjuvant, wherein a depicts the bond linking R.sup.1 to the piperazine moiety; and R.sup.5 and R.sup.6 are independently selected from H, halo, cyano, alkyl, cyclopropyl, aryl, heteroaryl, each of said aryl and heteroaryl groups being optionally substituted by one or more group(s) selected from halo, alkyl, cyclopropyl, or R.sup.5 and R.sup.6 together form a phenyl moiety fused to the phenyl ring they are attached to; and R.sup.8, R.sup.8, R.sup.9, R.sup.9 and R.sup.10 are independently selected from H, halo, haloalkyl, cyclopropyl or haloalkoxy, or R.sup.8, R.sup.8, R.sup.9, R.sup.9 are H and R.sup.10 is phenoxy; wherein, in formula Ie-1 when: R.sup.1 is H, and R.sup.5 and R.sup.6 are independently selected from H, halo, cyano, C1-C3 alkyl, and Ar.sup.2 is a 5- to 6-membered aryl or heteroaryl group optionally substituted by one or more group(s) selected from halo, C1-C3alkyl, hydroxyl, alkoxy, or fused to an aryl group optionally substituted by one or more further halo, C1-C3 alkyl, hydroxyl, methoxy then, R.sup.6 is H and R.sup.5 is H, halo, or R.sup.5 is H and R.sup.6 is halo, cyano, C1-C3 alkyl, C1 haloalkyl, or R.sup.5 and R.sup.6 are independently halo, and Ar.sup.2 is quinolin-2-yl, isoquinolin-3-yl, 8-haloquinolin-2-yl, benzothiazol-2-yl, 4,5,6,7-tetrahydro-1,3-benzothiazol-2-yl.

6. The pharmaceutical composition according to claim 3 comprising a compound selected from formulae If-1, If-2, If-3, If-4, If-5, If-6, If-7 and If-8 ##STR00067## ##STR00068## or a pharmaceutically acceptable salt or solvate thereof and at least one pharmaceutically acceptable carrier, diluent, excipient and/or adjuvant, wherein a designates the bond linking R.sup.1 to the piperazine moiety; and R.sup.11, R.sup.12, R.sup.12 and R.sup.13 are independently selected from H, halo, cyano, alkyl, hydroxyalkyl, haloalkyl, C3-C6 cycloalkyl, heteroalkyl, heterocyclyl, aryl, heteroaryl, -hydroxyl, alkoxy, haloalkoxy, alkylamino, carboxy, alkoxycarbonyl, alkylcarbonyloxy, alkylcarbonylamino, haloalkylcarbonylamino, acylamino, carbamoyl, alkylcarbamoyl, carbamoylalkyl, carbamoylamino, alkylcarbamoylamino, alkylsulfonyl, haloalkylsulfonyl, sulfamoyl, alkylsulfamoyl, alkylsulfonylamino, haloalkylsulfonylamino, or R.sup.12 together with R.sup.11 or R.sup.13, or R.sup.13 together with R.sup.12 forms an alkylenedioxy group or a haloalkylenedioxy group, or R.sup.12 together with R.sup.11 or R.sup.13 forms a cycloalkyl, aryl, heterocyclyl or heteroaryl moiety fused to the pyridyl group to which they are attached, each of said groups being optionally substituted by one or more group(s) selected from halo, cyano, alkyl, haloalkyl, cyclopropyl, alkoxy, haloalkoxy or hydroxyl; and Ar.sup.5 is a heterocyclyl, aryl, heteroaryl, aralkyl, heteroarylalkyl, or arylsulfonylalkyl group, each of which being optionally substituted by one or more group(s) selected from halo, cyano, alkyl, haloalkyl, cyclopropyl, alkoxy, haloalkoxy, heterocyclyl optionally substituted by alkyl, aryl, hydroxyl, alkoxy, alkoxyalkyl, hydroxyalkoxy, alkylamino, alkylsulfonylamino, aminoalkoxy, or alkoxycarbonylaminoalkoxy; and X.sup.3 is O or S; and R.sup.14 is H or methyl; and Ar.sup.6 is a heterocyclyl, aryl or heteroaryl group, each of which being optionally substituted by one or more group(s) selected from halo, cyano, alkyl, haloalkyl, cyclopropyl, alkoxy, haloalkoxy, aryl or hydroxyl; and R.sup.15 is H or methyl; and R.sup.16 is a heterocyclyl, aryl or heteroaryl group, each of said groups being optionally substituted by one or more group(s) selected from halo, cyano, alkyl, haloalkyl, cyclopropyl, alkoxy, haloalkoxy or hydroxyl; R.sup.17 is H, methyl or R.sup.17 together with R.sup.16 forms a cycloalkyl or aryl moiety fused to the thiazolyl group to which they are attached, thus forming a fused ring system, said fused ring system being optionally substituted by one or more group(s) selected from halo, cyano, alkyl, haloalkyl, cyclopropyl, alkoxy, haloalkoxy or hydroxyl; and X.sup.5 is O or S, or NR.sup.36 wherein R.sup.36 is H or C1-C3 alkyl; and Ar.sup.7 is a heterocyclyl, aryl or heteroaryl group, each of which being optionally substituted by one or more group(s) selected from halo, cyano, alkyl, haloalkyl, cyclopropyl, alkoxy, haloalkoxy, aryl or hydroxyl; and X.sup.6 is O, S or NR.sup.36 wherein R.sup.36 is H or C1-C3 alkyl; and R.sup.14 is H or methyl; and R.sup.34 is H, alkyl, alkoxyalkyl, hydroxyalkyl, alkoxycarbonylaminoalkyl; and R.sup.35 is H, alkyl, alkoxyalkyl, hydroxyalkyl, alkoxycarbonylaminoalkyl; and wherein, in formula If-1 when: R.sup.1 is H, and Ar.sup.1 is a 6-membered aryl optionally substituted by one or more group(s) selected from halo, cyano, C1-C3 alkyl, C1-haloalkyl, and R.sup.11, R.sup.12, R.sup.12 and R.sup.13 are independently selected from H, halo, C1-C3 alkyl, hydroxyl, methoxy, or R.sup.12 together with R.sup.11 or R.sup.13 forms an aryl or heterocyclyl or heteroaryl moiety fused to the pyridyl group to which they are attached and being optionally substituted by one or more group(s) selected from halo, C1-C3 alkyl, methoxy or hydroxyl, then, Ar.sup.1 is phenyl, 3-halophenyl, 4-halophenyl, 2,3-dichlorophenyl, 3,4-dihalophenyl, 3,4,5-trihalophenyl, 4-cyanophenyl, 4-(C1-C3 alkyl)phenyl, 4-(C1 haloalkyl)phenyl, and R.sup.11, R.sup.12, R.sup.12 and R.sup.13 together with the pyridyl group they are attached form a quinolin-2-yl, isoquinolin-3-yl or 8-haloquinolin-2-yl moiety; and in formula If-4 when: R.sup.1 is H, and Ar.sup.1 is a 6-membered aryl optionally substituted by one or more group(s) selected from halo, cyano, C1-C3 alkyl, C1-haloalkyl, and R.sup.17 together with R.sup.16 forms a cycloalkyl or aryl moiety fused to the thiazolyl group to which they are attached, thus forming a fused ring system, said fused ring system being optionally substituted by one or more group(s) selected from halo, C1-3 alkyl, methoxy or hydroxyl, then Ar.sup.1 is phenyl, 3-halophenyl, 4-halophenyl, 2,3-dichlorophenyl, 3,4-dihalophenyl, 3,4,5-trihalophenyl, 4-cyanophenyl, 4-(C1-C3 alkyl)phenyl, 4-(C1 haloalkyl)phenyl, and R.sup.17 and R.sup.16 form together with the thiazolyl group to which they are attached a benzothiazol-2-yl or 4,5,6,7-tetrahydro-1,3-benzothiazol-2-yl moiety.

7. The pharmaceutical composition according to claim 6 comprising a compound selected from formulae Ig-1, Ig-2, Ig-3, Ig-4, Ig-5, Ig-6, Ig-7 and Ig-8 ##STR00069## ##STR00070## or a pharmaceutically acceptable salt or solvate thereof and at least one pharmaceutically acceptable carrier, diluent, excipient and/or adjuvant, wherein a depicts the bond linking R.sup.1 to the piperazine moiety; and R.sup.12 and R.sup.13 are independently selected from H, halo, cyano, alkyl, hydroxyalkyl, haloalkyl, cycloalkyl, heteroalkyl, hydroxyl, alkoxy, haloalkoxy, carboxy, alkoxycarbonyl, alkylcarbonyloxy, alkylcarbonylamino, haloalkylcarbonylamino, acylamino, carbamoyl, alkylcarbamoyl, carbamoylalkyl, carbamoylamino, alkylcarbamoylamino, alkylsulfonyl, haloalkylsulfonyl, sulfamoyl, alkylsulfamoyl, alkylsulfonylamino, haloalkylsulfonylamino, or R.sup.13 together with R.sup.12 forms an alkylenedioxy group or a haloalkylenedioxy group, each of said groups being optionally substituted by one or more group(s) selected from halo, cyano, alkyl, haloalkyl, alkoxy, haloalkoxy, hydroxyl or oxo; and R.sup.18, R.sup.19, R.sup.19 and R.sup.20 are independently selected from H, halo, cyano, alkyl, haloalkyl, cyclopropyl, alkoxy, haloalkoxy; and R.sup.21, R.sup.21, R.sup.22, R.sup.22 and R.sup.23 are independently selected from H, halo, cyano, alkyl, haloalkyl, cyclopropyl, heterocyclyl optionally substituted by alkyl, hydroxyl, alkoxy, haloalkoxy, hydroxyalkoxy, alkylamino, alkylsulfonylamino, aminoalkoxy, alkoxycarbonylaminoalkoxy; and R.sup.24, R.sup.24, R.sup.25, R.sup.25 and R.sup.26 are independently selected from H, halo haloalkyl, cyclopropyl; and R.sup.27, R.sup.28, R.sup.29 and R.sup.30 are independently selected from H, halo, cyano, alkyl, haloalkyl, cyclopropyl, alkoxy, haloalkoxy; and R.sup.27, R.sup.28, R.sup.29 and R.sup.30 are absent, or R.sup.27, R.sup.28, R.sup.29 and R.sup.30 are H under the condition that R.sup.28, R.sup.29 and R.sup.30 are H and that R.sup.27 is selected from H, chloro or fluoro; and the two bonds represented by the dotted lines in formula Ig-4 are both absent, or both present under the condition that R.sup.27, R.sup.28, R.sup.29 and R.sup.30 are absent; and R.sup.31, R.sup.31, R.sup.32, R.sup.32 and R.sup.33 are independently selected from H, halo, cyano, alkyl, haloalkyl, cyclopropyl, alkoxy, haloalkoxy; and wherein, in formula Ig-1 when: R.sup.1 is H, and Ar.sup.1 is a 6-membered aryl optionally substituted by one or more group(s) selected from halo, cyano, C1-C3 alkyl, C1-haloalkyl, and R.sup.12, R.sup.13, R.sup.18, R.sup.19, R.sup.19 and R.sup.20 are independently selected from H, halo, C1-3 alkyl, hydroxyl, methoxy, then, Ar.sup.1 is phenyl, 3-halophenyl, 4-halophenyl, 2,3-dichlorophenyl, 3,4-dihalophenyl, 3,4,5-trihalophenyl, 4-cyanophenyl, 4-(C1-C3 alkyl)phenyl, 4-(C1 haloalkyl)phenyl, and R.sup.12, R.sup.13, R.sup.18, R.sup.19, R.sup.19 and R.sup.20 are H, or R.sup.12, R.sup.13, R.sup.19, R.sup.19, R.sup.20 are H and R.sup.18 is fluoro, chloro, and in formula Ig-4 when R.sup.1 is H, and Ar.sup.1 is a 6-membered aryl optionally substituted by one or more group(s) selected from halo, cyano, C1-C3 alkyl, C1-haloalkyl, and R.sup.27, R.sup.28, R.sup.29 and R.sup.30 are independently selected from H, halo, C1-3 alkyl, methoxy, and R.sup.27, R.sup.28, R.sup.29 and R.sup.30 are absent or H under the condition that R.sup.28, R.sup.29 and R.sup.30 are H and R.sup.27 is selected from H, chloro or fluoro, then Ar.sup.1 is phenyl, 3-halophenyl, 4-halophenyl, 2,3-dichlorophenyl, 3,4-dihalophenyl, 3,4,5-trihalophenyl, 4-cyanophenyl, 4-(C1-C3 alkyl)phenyl, 4-(C1 haloalkyl)phenyl, and R.sup.27, R.sup.28, R.sup.29 and R.sup.30 are H, and R.sup.27, R.sup.28, R.sup.29 and R.sup.30 are absent or H under the condition that R.sup.27, R.sup.28, R.sup.29 and R.sup.30 are H.

8. The pharmaceutical composition according to claim 6 comprising a compound having formula Ih-2 ##STR00071## or a pharmaceutically acceptable salt or solvate thereof and at least one pharmaceutically acceptable carrier, diluent, excipient and/or adjuvant, wherein a designates the bond linking R.sup.1 to the piperazine moiety; and R.sup.14 is H or methyl; and X.sup.4 is O, CH.sub.2, CF.sub.2, C(CH.sub.3).sub.2, N(C1-C3 alkyl)N-phenyl; and R.sup.36a, R.sup.36b, R.sup.36a, R.sup.37a and R.sup.37a are independently selected from H, C1-C3 alkyl, alkoxyC1-C3 alkyl.

9. The pharmaceutical composition according to claim 3 comprising a compound selected from formulae Ii-1, Ii-2, Ii-3, Ii-4, Ii-5, Ii-6, Ii-7, Ii-8, Ij-1, Ij-2, Ij-3, Ij-4, Ij-5, Ij-6, Ij-7, Ij-8, Ik-1, Ik-2, Ik-3, Ik-4, Ik-5, Ik-6, Ik-7, Ik-8, Ii-1, Ii-2, Ii-3, Ii-4, Ii-5, Ii-6, Ii- 7 and Ii-8 ##STR00072## ##STR00073## ##STR00074## ##STR00075## ##STR00076## ##STR00077## ##STR00078## ##STR00079## ##STR00080## or a pharmaceutically acceptable salt or solvate thereof and at least one pharmaceutically acceptable carrier, diluent, excipient and/or adjuvant, wherein a depicts the bond linking R.sup.1 to the piperazine moiety; and Ar.sup.4, R.sup.4, R.sup.4, R.sup.5, R.sup.5, R.sup.6, R.sup.7, R.sup.7, M.sup.1, M.sup.2 are as defined in claim 4; and Ar.sup.5, Ar.sup.6, Ar.sup.7, R.sup.11, R.sup.12, R.sup.12, R.sup.13, R.sup.14, R.sup.14, R.sup.15, R.sup.16, R.sup.17, R.sup.34, R.sup.35, X.sup.3, X.sup.5, X.sup.6, and are as defined in claim 6.

10. The pharmaceutical composition according to claim 9 comprising a compound selected from formulae Il-1, Il-2, Il-3, Il-4, Il-5, Il-6, Il-7, Il-8, Il-1, Il-2, Il-3, Il-4, Il-5, Il-6, Il-7, Il-8 ##STR00081## ##STR00082## ##STR00083## ##STR00084## ##STR00085## ##STR00086## or a pharmaceutically acceptable salt or solvate thereof and at least one pharmaceutically acceptable carrier, diluent, excipient and/or adjuvant, wherein: a depicts the bond linking R.sup.1 to the piperazine moiety; and R.sup.4, R.sup.4, R.sup.5, R.sup.5, R.sup.6, M.sup.1 and M.sup.2 are as defined in claim 4; and R.sup.12, R.sup.13, R.sup.14, R.sup.14, R.sup.15, R.sup.18, R.sup.19, R.sup.19, R.sup.20, R.sup.21, R.sup.21, R.sup.22, R.sup.22, R.sup.23, R.sup.24, R.sup.24, R.sup.25, R.sup.25, R.sup.26, R.sup.27, R.sup.27, R.sup.28, R.sup.28, R.sup.29, R.sup.29, R.sup.30, R.sup.30, R.sup.31, R.sup.31, R.sup.32, R.sup.32, R.sup.33, R.sup.34, R.sup.35, X.sup.3, X.sup.5; X.sup.6; and the two bonds represented by the dotted lines are as defined in claim 7.

11. The pharmaceutical composition according to claim 10 comprising a compound selected from formulae Im-1, Im-2, Im-3, Im-4, Im-5, Im-6, Im-7, Im-8, Im-1, Im-2, Im-3, Im-4, Im-5, Im-6, Im-7 and Im-8 ##STR00087## ##STR00088## ##STR00089## ##STR00090## ##STR00091## ##STR00092## or a pharmaceutically acceptable salt or solvate thereof and at least one pharmaceutically acceptable carrier, diluent, excipient and/or adjuvant, wherein: a designates the bond linking R.sup.1 to the piperazine moiety; and R.sup.5, R.sup.6, M.sup.1 and M.sup.2 are as defined in claim 5; and R.sup.12, R.sup.13, R.sup.14, R.sup.14, R.sup.15, R.sup.18, R.sup.19, R.sup.19, R.sup.20, R.sup.21, R.sup.21, R.sup.22, R.sup.22, R.sup.23, R.sup.24, R.sup.24, R.sup.25, R.sup.25, R.sup.26, R.sup.27, R.sup.27, R.sup.28, R.sup.28, R.sup.29, R.sup.29, R.sup.30, R.sup.30, R.sup.31, R.sup.31, R.sup.32, R.sup.32, R.sup.33, R.sup.34, R.sup.35, X.sup.3, X.sup.5, X.sup.6; and the two bonds represented by the dotted lines are as defined in claim 7.

12. The pharmaceutical composition according to claim 1 comprising at least one pharmaceutically acceptable carrier, diluent, excipient and/or adjuvant and a compound selected from the group consisting of: (3-(4-chlorophenyl)-1H-pyrazol-5-yl)(3-(pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(3,4-dichlorophenyl)-1H-pyrazol-5-yl)(3-(pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; [1,1-biphenyl]-4-yl(3-(pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(2-morpholinothiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(5-chloropyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (4-fluorophenyl)(8-methyl-3-(pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2,4-dichlorophenyl)-1H-pyrazol-5-yl)(3-(pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(3,4-dichlorophenyl)-1-methyl-1H-pyrazol-5-yl)(3-(pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(isoquinolin-3-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluoro-[1,1-biphenyl]-4-yl)(3-(pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(3-(4-(trifluoromethyl)phenyl)-1H-pyrazol-5-yl)methanone; (3-(4-phenoxyphenyl)-1H-pyrazol-5-yl)(3-(pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; [1,1-biphenyl]-4-yl(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; [1,1-biphenyl]-4-yl(3-(2-morpholinothiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(8-fluoroquinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(8-chloroquinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (4-fluorophenyl)(3-(2-(4-(trifluoromethyl)phenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(6-phenylpyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; [1,1-biphenyl]-4-yl(3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(4,5,6,7-tetrahydrobenzo[d]thiazol-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(2-(3-(trifluoromethyl)phenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(2,4-difluorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (3-(2-(2,3-dichlorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (3-(2-(4-chlorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (4-fluorophenyl)(3-(2-(4-fluorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(2-(piperidin-1-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(2-(4-phenylpiperazin-1-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(2,4-dichlorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (3-(2-(3,5-dichlorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (4-fluorophenyl)(3-(6-(pyrrolidin-1-yl)pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(6-morpholinopyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(6-(trifluoromethyl)pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(3,4-dimethoxyphenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (4-fluorophenyl)(8-(4-fluorophenyl)-3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(3-chlorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (4-fluorophenyl)(8-isopropyl-3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-(4-fluorophenyl)(8-methyl-3-(pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-(4-fluorophenyl)(8-methyl-3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; [1,1-biphenyl]-4-yl(8-methyl-3-(2-morpholinothiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(2-phenyloxazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(8-methyl-3-(2-phenyloxazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; [1,1-biphenyl]-4-yl(8-methyl-3-(2-phenyloxazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; [1,1-biphenyl]-4-yl(3-(2-phenyloxazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(8-(2-hydroxyethyl)-3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(8-methyl-3-(2-morpholinothiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluoro-[1,1-biphenyl]-4-yl)(8-methyl-3-(2-morpholinothiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-morpholinothiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (8-methyl-3-(2-morpholinothiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(4-phenylthiazol-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(2-chlorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4] triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (3-(benzo[d]thiazol-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (8,8-dimethyl-3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (4-fluorophenyl)(8-methyl-3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (8-methyl-3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-3-yl)phenyl)methanone; (8-methyl-3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-3-yl)phenyl)methanone; (8-methyl-3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(2-chlorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; [1,1-biphenyl]-4-yl(3-(2-(2-chlorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-(3-(2-(4-chlorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-(4-fluorophenyl)(3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; [1,1-biphenyl]-4-yl(8-methyl-3-(4-methyl-2-phenylthiazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(4-fluorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(2-chlorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (4-fluorophenyl)(8-methyl-3-(4-methyl-2-phenylthiazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; [1,1-biphenyl]-4-yl(3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(2,4-difluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; [1,1-biphenyl]-4-yl(3-(2-(2,4-difluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(2,4-difluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; naphthalen-1-yl(3-(pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(4-chlorophenyl)-1-methyl-1H-pyrazol-5-yl)(3-(pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (5-(4-chlorophenyl)-1-methyl-1H-pyrazol-3-yl)(3-(pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (8-methyl-3-(5-phenyl-1,2,4-oxadiazol-3-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (8-methyl-3-(3-phenyl-1,2,4-oxadiazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (R)-(3-(2-(4-fluorophenyl)oxazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; 2-(7-((4-fluorophenyl)sulfonyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)quinoline; 2-(4-fluorophenyl)-1-(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)ethanone; (5-phenylpyridin-2-yl)(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (6-phenylpyridin-3-yl)(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (2-phenylpyrimidin-5-yl)(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-phenylcyclohexyl)(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; cyclohexyl(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; 3-methyl-1-(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)butan-1-one; [1,1-biphenyl]-2-yl(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-(furan-3-yl)phenyl)(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-(pyrimidin-5-yl)phenyl)(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (9-methyl-9H-carbazol-2-yl)(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-(pyrimidin-2-yl)phenyl)(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-(pyrazin-2-yl)phenyl)(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-(pyridazin-3-yl)phenyl)(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; 4-(3-(quinolin-2-yl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine-7-carbonyl)-[1,1-biphenyl]-4-carbonitrile; 1-(4-(3-(quinolin-2-yl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine-7-carbonyl)phenyl)piperidin-2-one; (4-morpholinophenyl)(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-(3,5-dimethyl-1H-pyrazol-1-yl)phenyl)(3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(4-fluorophenyl)thiazol-4-yl)-6-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(4-fluorophenyl)thiazol-4-yl)-5-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3,4-dichlorophenyl)(3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3,4-difluorophenyl)(3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-chloro-4-fluorophenyl)(3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-chloro-3-fluorophenyl)(3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(3,4,5-trifluorophenyl)methanone; (8-methyl-3-(2-phenyloxazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (R)-(4-fluorophenyl)(8-methyl-3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-[1,1-biphenyl]-4-yl(8-methyl-3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-[1,1-biphenyl]-4-yl(8-methyl-3-(2-morpholinothiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-(4-fluorophenyl)(8-methyl-3-(6-phenylpyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-[1,1-biphenyl]-4-yl(8-methyl-3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-(4-fluorophenyl)(8-methyl-3-(4,5,6,7-tetrahydrobenzo[d]thiazol-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-(3-(2-(2,4-difluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (R)-(3-(2-(2,3-dichlorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (R)-(4-fluorophenyl)(8-methyl-3-(2-(4-phenylpiperazin-1-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-(3-(2-(2,4-dichlorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (R)-(3-(2-(3-chlorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (R)-(4-fluorophenyl)(8-methyl-3-(2-phenyloxazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-[1,1-biphenyl]-4-yl(8-methyl-3-(2-phenyloxazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-(4-fluorophenyl)(8-(2-hydroxyethyl)-3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-(4-fluoro-[1,1-biphenyl]-4-yl)(8-methyl-3-(2-morpholinothiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-(8-methyl-3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (R)-(8-methyl-3-(2-morpholinothiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (R)-(4-fluorophenyl)(8-methyl-3-(4-phenylthiazol-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-(3-(2-(2-chlorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (R)-(8-methyl-3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-3-yl)phenyl)methanone; (R)-(8-methyl-3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (R)-(3-(2-(2-chlorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (R)-[1,1-biphenyl]-4-yl(3-(2-(2-chlorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-[1,1-biphenyl]-4-yl(8-methyl-3-(4-methyl-2-phenylthiazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-(3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (R)-[1,1-biphenyl]-4-yl(3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-[1,1-biphenyl]-4-yl(3-(2-(2,4-difluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-(3-(2-(2,4-difluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (S)-(4-fluorophenyl)(8-methyl-3-(pyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (S)-(4-fluorophenyl)(3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (S)-(4-fluoro-[1,1-biphenyl]-4-yl)(8-methyl-3-(2-morpholinothiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (S)-(4-fluorophenyl)(8-methyl-3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (S)-(8-methyl-3-(quinolin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (S)-(4-fluorophenyl)(3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (S)-(3-(2-(2,4-difluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(8-methyl-3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (S)-(4-fluorophenyl)(8-methyl-3-(2-phenylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (S)-(3-(3-(4-fluorophenyl)-1,2,4-oxadiazol-5-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (R)-(3-(3-(4-fluorophenyl)-1,2,4-oxadiazol-5-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(2,4-difluorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(5-phenyl-1,2,4-oxadiazol-3-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(3-phenyl-1,2,4-oxadiazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(5-phenyl-1,2,4-oxadiazol-3-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(3-phenyl-1,2,4-oxadiazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(3-(4-fluorophenyl)-1,2,4-oxadiazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(3-(4-fluorophenyl)-1,2,4-oxadiazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(3-(2,4-difluorophenyl)-1,2,4-oxadiazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(5-phenyl-1H-1,2,4-triazol-3-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(5-phenyl-1H-1,2,4-triazol-3-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(2-(2-fluorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(2-fluorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; [1,1-biphenyl]-4-yl(3-(2-(2-fluorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluoro-[1,1-biphenyl]-4-yl)(3-(2-(2-fluorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(3-(2,4-difluorophenyl)-1,2,4-oxadiazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; [1,1-biphenyl]-4-yl(3-(2-((4,5-dichloro-1H-imidazol-1-yl)methyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-((4,5-dichloro-1H-imidazol-1-yl)methyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluoro-[1,1-biphenyl]-4-yl)methanone; (3-(2-(4-chlorobenzyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (3-(2-(4-chlorobenzyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(2-(p-tolyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-(thiophen-2-yl)phenyl)(3-(2-(p-tolyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; [1,1-biphenyl]-4-yl(3-(2-(p-tolyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(2-(thiophen-2-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-(thiophen-2-yl)phenyl)(3-(2-(thiophen-2-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; [1,1-biphenyl]-4-yl(3-(2-(thiophen-2-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluoro-[1,1-biphenyl]-4-yl)(3-(2-(thiophen-2-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(((4-chlorophenyl)sulfonyl)methyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; [1,1-biphenyl]-4-yl(3-(2-(((4-chlorophenyl)sulfonyl)methyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(((4-chlorophenyl)sulfonyl)methyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluoro-[1,1-biphenyl]-4-yl)methanone; (4-fluorophenyl)(3-(2-(2-methoxyphenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(2-methoxyphenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; [1,1-biphenyl]-4-yl(3-(2-(2-methoxyphenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; [1,1-biphenyl]-4-yl(3-(3-(4-fluorophenyl)-1,2,4-oxadiazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluoro-[1,1-biphenyl]-4-yl)(3-(3-(4-fluorophenyl)-1,2,4-oxadiazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(2-(3-fluorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(3-fluorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(3-(4-fluorophenyl)-1,2,4-oxadiazol-5-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(3-phenyl-1,2,4-thiadiazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(3-phenyl-1,2,4-thiadiazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(4-bromophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(4-bromophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(5-methylthiophen-2-yl)phenyl)methanone; 4-(3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine-7-carbonyl)benzonitrile; [1,1-biphenyl]-4-yl(3-(3-phenyl-1,2,4-oxadiazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(2-(pyridin-4-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(quinolin-2-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(1-methyl-3-phenyl-1H-pyrazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(4-(dimethylamino)phenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (3-(1-methyl-5-phenyl-1H-pyrazol-3-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluoro-[1,1-biphenyl]-4-yl)(3-(3-phenyl-1,2,4-oxadiazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(pyridin-2-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(1-methyl-3-phenyl-1H-pyrazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(pyrimidin-2-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (S)-(8-methyl-3-(2-morpholinothiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(pyridin-4-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(4-(dimethylamino)phenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(2-(pyridin-2-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (S)-(3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(2-methylthiophen-3-yl)phenyl)methanone; (R)-(3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(2-methylthiophen-3-yl)phenyl)methanone; (3-(2-(pyrazin-2-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; 4-(4-(7-(4-(thiophen-2-yl)benzoyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)thiazol-2-yl)benzonitrile; (4-fluorophenyl)(3-(2-(pyrazin-2-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(3-(1-methyl-5-phenyl-1H-pyrazol-3-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(4-morpholinophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(2-(4-morpholinophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(4-(4-methylpiperazin-1-yl)phenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(2-(4-(4-methylpiperazin-1-yl)phenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(4-(piperidin-1-yl)phenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(2-(4-(piperidin-1-yl)phenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(4-(pyrrolidin-1-yl)phenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(2-(4-(pyrrolidin-1-yl)phenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(piperidin-1-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(pyrrolidin-1-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(2-(pyrrolidin-1-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(4-methylpiperazin-1-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(2-(4-methylpiperazin-1-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(1-methyl-2-phenyl-1H-imidazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-(dimethylamino)phenyl)(3-(2-(4-fluorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(1-(2-methoxyethyl)-3-phenyl-1H-pyrazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(1-(2-methoxyethyl)-3-phenyl-1H-pyrazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-isobutylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(2-(2-methoxyethyl)morpholino)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(4,4-difluoropiperidin-1-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (3-(2-(2,5-dimethylmorpholino)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(2-hydroxyphenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(4,4-difluoropiperidin-1-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(2,6-dimethylmorpholino)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(2,2-dimethylmorpholino)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(3-phenyl-1H-pyrazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(3-methylthiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(3-phenyl-1H-pyrazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (R)-(3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(3-methylthiophen-2-yl)phenyl)methanone; (4-fluorophenyl)(3-(2-(2-hydroxyphenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (S)-(3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(3-methylthiophen-2-yl)phenyl)methanone; (3-(2-(2-methylmorpholino)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(4,4-dimethylpiperidin-1-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(5-methylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(4,4-dimethylpiperidin-1-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; (4-fluorophenyl)(3-(2-(2-(methoxymethyl)piperidin-1-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (4-fluorophenyl)(8-methyl-3-(6-methylpyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(2-(2-(methoxymethyl)piperidin-1-yl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; tert-butyl (2-(2-(4-(7-(4-(thiophen-2-yl)benzoyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)thiazol-2-yl)phenoxy)ethyl)carbamate; (3-(2-(2-(2-hydroxyethoxy)phenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(2-(2-aminoethoxy)phenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; N-(4-(4-(7-(4-(thiophen-2-yl)benzoyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)thiazol-2-yl)phenyl)methanesulfonamide; (3-(1-(2-hydroxyethyl)-3-phenyl-1H-pyrazol-5-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(1-(2-hydroxyethyl)-5-phenyl-1H-pyrazol-3-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; [1,1-biphenyl]-4-yl(8-methyl-3-(6-methylpyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (8-methyl-3-(6-methylpyridin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(2,4-difluorophenyl)-5-methylthiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(3-(dimethylamino)phenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(3-(dimethylamino)phenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-fluorophenyl)methanone; N-(3-(4-(7-(4-(thiophen-2-yl)benzoyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)thiazol-2-yl)phenyl)methanesulfonamide; N-(2-(4-(7-(4-(thiophen-2-yl)benzoyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)thiazol-2-yl)phenyl)methanesulfonamide; (3-(4-chlorophenyl)-1H-pyrazol-5-yl)(3-(2-(4-fluorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(4-chlorophenyl)-1-methyl-1H-pyrazol-5-yl)(3-(2-(4-fluorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (3-(3,4-dichlorophenyl)-1-methyl-1H-pyrazol-5-yl)(3-(2-(4-fluorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; (5-(4-chlorophenyl)-1-methyl-1H-pyrazol-3-yl)(3-(2-(4-fluorophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone; tert-butyl (2-(3-phenyl-5-(7-(4-(thiophen-2-yl)benzoyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)-1H-pyrazol-1-yl)ethyl)carbamate; tert-butyl (2-(5-phenyl-3-(7-(4-(thiophen-2-yl)benzoyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)-1H-pyrazol-1-yl)ethyl)carbamate; (3-(2-(2-bromophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; (3-(2-(3-bromophenyl)thiazol-4-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)(4-(thiophen-2-yl)phenyl)methanone; 2-(4-(7-(4-(thiophen-2-yl)benzoyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)thiazol-2-yl)benzonitrile; 3-(4-(7-(4-(thiophen-2-yl)benzoyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazin-3-yl)thiazol-2-yl)benzonitrile; (3-(2-(4-fluorophenyl)thiazol-4-yl)-8-methyl-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-; methylthiophen-3-yl)phenyl)methanone; and pharmaceutically acceptable salts and solvates thereof.

Description

BIOLOGY EXAMPLES

Brief Description of the Drawings

(1) FIG. 1 shows the effects of a single intravenous 10 mg/kg dose of compound n.sup.o 156 on LH serum levels in castrated male rats, measured 60 min and 120 min following dosing. LH hormone levels are expressed as meansS.E.M. (**p<0.001 vs. baseline, determined by one-Way ANOVA and Dunnett's post hoc).

(2) FIG. 2 shows the effects of a single intravenous dose of compound n.sup.o 144 (10 mg/kg), compound 71 (15 mg/kg) and compound 114 (20 mg/kg) on LH serum levels in castrated male rats, measured 60 min following dosing. LH hormone levels are expressed as meansS.E.M. (**p<0.001 vs. baseline, determined by one-Way ANOVA and Dunnett's post hoc).

(3) FIG. 3 shows the effect of a single intravenous 20 mg/kg dose of compound n.sup.o 156 on testosterone plasma levels in gonad-intact male rats (N=5 rats/group). Plasma testosterone levels are represented as an integrated testosterone response (AUC) over a 420 min period following dosing.

COMPETITIVE BINDING ASSAYS

(4) The affinity of compounds of the invention for the tachykinin receptors was determined by measuring the ability of the compounds of the invention to displace a radiolabeled ligand from its specifics binding site.

(5) .sup.3H-SB222200 Binding Competition Assay with Human NK-3 Receptor

(6) The ability of the compounds of the invention to inhibit the binding of the NK-3 receptor selective antagonist SB222200 was assessed by an in vitro radioligand binding assay. Membranes were prepared from Chinese hamster ovary recombinant cells which express the human NK3 receptor. The membranes were incubated with 5 nM .sup.3H-SB222200_(ARC) in a HEPES 25 mM/NaCl 0.1M/CaCl.sub.2 1 mM/MgCl.sub.2 5 Mm/BSA 0.5%/Saponin 10 g/ml buffer at pH 7.4 and various concentrations of the compounds of the invention. The amount of tritiated SB222200 bound to the receptor was determined after filtration by the quantification of membrane associated radioactivity using the TopCount-NXT reader (Packard). Competition curves were obtained for compounds of the invention and the concentrations of compounds which displaced 50% of bound radioligand (IC.sub.50) were determined and then apparent inhibition constant Ki values were calculated by the following equation: Ki=IC.sub.50/(1+[L]/K.sub.D) where [L] is the concentration of free radioligand and K.sub.D is its dissociation constant at the receptor, derived from saturation binding experiments (Cheng and Prusoff, 1973) (see results in table 3 below).
In Table 3 biological results obtained using the .sup.3H-SB222200 binding competition assay with compounds of the invention are set out in tabulated form. In this table the calculated Ki is given. The Ki value obtained (in accordance with the protocol set forth above) is represented as follows: +++ means Ki<500 nM; ++ means 500 nMKi1 M; + means 1 M<Ki5 M; # means Ki>5 M.

(7) TABLE-US-00005 TABLE 3 Compound no Ki range 1 + 2 + 3 + 4 + 5 + 6 + 7 +++ 8 +++ 9 +++ 10 +++ 11 +++ 13 + 14 + 15 + 16 + 17 + 18 + 19 +++ 20 +++ 21 +++ 22 ++ 23 ++ 24 +++ 25 +++ 26 +++ 27 +++ 28 +++ 29 +++ 30 +++ 31 +++ 32 +++ 33 +++ 34 +++ 35 +++ 36 +++ 37 +++ 38 +++ 39 ++ 40 +++ 41 +++ 42 +++ 43 + 44 + 45 +++ 46 +++ 47 +++ 48 +++ 49 +++ 50 +++ 51 +++ 52 +++ 53 +++ 54 +++ 55 +++ 56 +++ 57 +++ 58 +++ 59 +++ 60 +++ 61 +++ 62 +++ 63 +++ 64 +++ 65 +++ 66 +++ 67 +++ 68 +++ 69 +++ 70 +++ 71 +++ 72 +++ 73 +++ 74 +++ 75 ++ 76 +++ 77 +++ 78 +++ 79 +++ 80 +++ 83 # 85 +++ 90 +++ 91 +++ 92 + 93 + 95 + 96 # 103 + 107 ++ 108 ++ 109 +++ 110 +++ 111 +++ 112 +++ 113 +++ 114 +++ 115 +++ 118 +++ 131 +++ 134 +++ 135 +++ 136 +++ 144 +++ 156 +++ 159 # 160 + 161 + 162 +++ 163 ++ 164 +++ 165 +++ 166 +++ 167 ++ 168 +++ 169 +++ 170 +++ 171 +++ 172 +++ 173 +++ 174 +++ 175 +++ 176 +++ 177 +++ 178 + 179 +++ 180 +++ 181 +++ 182 +++ 183 +++ 185 # 186 + 187 + 188 ++ 189 +++ 190 +++ 191 # 193 +++ 194 +++ 195 +++ 196 +++ 198 + 199 + 200 ++ 201 + 202 +++ 203 ++ 204 +++ 205 ++ 206 + 207 +++ 208 + 209 +++ 211 +++ 212 +++ 213 +++ 214 +++ 215 +++ 216 +++ 217 +++ 218 + 219 +++ 220 +++ 221 ++ 222 +++ 223 +++ 224 +++ 225 + 226 # 227 ++ 228 +++ 229 +++ 230 + 231 + 232 + 233 +++ 234 +++ 235 +++ 236 +++ 238 +++ 239 + 240 ++ 241 +++ 242 ++ 244 ++ 245 +++ 246 +++ 247 +++ 248 +++ 249 +++ 250 ++ 252 ++ 253 ++ 254 +++ 255 ++ 256 +++ 257 +++ 258 +++ 259 + 260 +++ 261 +++ 262 +++ 263 +++ 265 +++ 266 +++ 267 +++ 268 +++ 269 ++ 271 +++ 273 +++ 274 ++ 275 # 276 # 277 # 278 +++ 279 +++ 280 +++ 281 +++ 282 ++ 283 ++ 284 +++ 285 +++ 286 +++ 287 +++
[.sup.125I]-His-MePhe7-Neurokinin B Binding Competition Assay with Rat NK-3 Receptor
The affinity of compounds of the invention for the rat NK3 receptor was evaluated in CHO recombinant cells which express the rat NK3 receptor. Membrane suspensions were prepared from these cells. The following radioligand: [.sup.125I]-His-MePhe7-Neurokinin B (PerkinElmer Cat # NEX285) was used in this assay. Binding assays were performed in a 25 nM HEPES/1 mM CaCl.sub.2/5 mM MgCl.sub.2/0.5% BSA/10 g/ml Saponin, at pH 7.4. Binding assays consisted of 25 l of membrane suspension (approximately 5 g protein/well in a 96 well plate), 50 l of compound or reference ligand (MePhe7-Neurokinin B) at increasing concentrations (diluted in assay buffer) and 0.09 nM [.sup.125I]-His-MePhe7-Neurokinin B. The plate was incubated 60 min at 25 C. in a water bath and then filtered over GF/C filters (Perkin Elmer, 6005174, presoaked in assay buffer without saponine for 2 h at room temperature) with a Filtration unit (Perkin Elmer). The radioactivity retained on the filters was measured by using the TopCount-NXT reader (Packard). Competition curves were obtained for compounds of the invention and the concentrations of compounds which displaced 50% of bound radioligand (IC.sub.50) were determined and then apparent inhibition constant Ki values were calculated by the following equation: Ki=IC.sub.50/(1+[L]/K.sub.D) where [L] is the concentration of free radioligand and K.sub.D is its dissociation constant at the receptor, derived from saturation binding experiments (Cheng and Prusoff, 1973).
When tested in above described assay, preferred compounds of the invention showed an inhibition constant (Ki) for rat NK-3 receptor <50 nM.
Selectivity Assay
Selectivity of the compounds of the invention was determined over the other human NK receptors, namely NK-1 and NK2 receptors.
Human NK1
The affinity of compounds of the invention for the NK1 receptor was evaluated in CHO recombinant cells which express the human NK1 receptor. Membrane suspensions were prepared from these cells. The following radioligand: [.sup.3H] substance P (PerkinElmer Cat # NET111520) was used in this assay. Binding assays were performed in a 50 mM Tris/5 mM MnCl2/150 mM NaCl/0.1% BSA at pH 7.4. Binding assays consisted of 25 l of membrane suspension (approximately 5 g of protein/well in a 96 well plate), 50 l of compound or reference ligand (Substance P) at increasing concentrations (diluted in assay buffer) and 2 nM [.sup.3H] substance P. The plate was incubated 60 min at 25 C. in a water bath and then filtered over GF/C filters (Perkin Elmer, 6005174, presoaked in 0.5% PEI for 2 h at room temperature) with a Filtration unit (Perkin Elmer). The radioactivity retained on the filters was measured by using the TopCount-NXT reader (Packard). Competition curves were obtained for compounds of the invention and the concentrations of compounds which displaced 50% of bound radioligand (IC.sub.50) were determined and then apparent inhibition constant Ki values were calculated by the following equation: Ki=IC.sub.50/(1+[L]/K.sub.D) where [L] is the concentration of free radioligand and K.sub.D is its dissociation constant at the receptor, derived from saturation binding experiments (Cheng and Prusoff, 1973).
Human NK2
The affinity of compounds of the invention for the NK2 receptor was evaluated in CHO recombinant cells which express the human NK2 receptor. Membrane suspensions were prepared from these cells. The following radioligand [.sup.125I]-Neurokinin A (PerkinElmer Cat # NEX252) was used in this assay. Binding assays were performed in a 25 mM HEPES/1 mM CaCl2/5 mM MgCl2/0.5% BSA/10 g/ml saponin, at pH 7.4. Binding assays consisted of 25 l of membrane suspension (approximately 3.75 g of protein/well in a 96 well plate), 50 l of compound or reference ligand (Neurokinin A) at increasing concentrations (diluted in assay buffer) and 0.1 nM [.sup.125I]-Neurokinin A. The plate was incubated 60 min at 25 C. in a water bath and then filtered over GF/C filters (Perkin Elmer, 6005174, presoaked in assay buffer without saponine for 2 h at room temperature) with a Filtration unit (Perkin Elmer). The radioactivity retained on the filters was measured by using the TopCount-NXT reader (Packard). Competition curves were obtained for compounds of the invention and the concentrations of compounds which displaced 50% of bound radioligand (IC.sub.50) were determined and then apparent inhibition constant Ki values were calculated by the following equation: Ki=IC.sub.50/(1+[L]/K.sub.D) where [L] is the concentration of free radioligand and K.sub.D is its dissociation constant at the receptor, derived from saturation binding experiments (Cheng and Prusoff, 1973).
The compounds of the invention, which were tested in the above NK-1 and NK-2 described assays, demonstrated a low affinity at the human NK-1 and human NK-2 receptors: 100-200 fold shift of the Ki compared to the human NK-3 receptor. Thus, compounds according to the invention have been shown to be selective over NK1 and NK2 receptors.
In Vivo Assay to Assess Compound Activity in Rat
The inhibitory effect of the compounds of the invention in luteinizing hormone (LH) secretion and on circulating steroid levels are determined by the following biological studies.
Castrated Male Rat Model to Assess the Effect of Compound of Invention on Circulating Levels of Luteinizing Hormone (LH).
In humans and rodents, castration is well-precedented to permit heightened, persistent GnRH signaling and consequently elevation of circulating LH. Thus, in this animal model, LH is measured in castrated rats as a marker of test compound inhibition of the GnRH signaling pathway.
Castrated adult male Sprague-Dawley (SD) rats (150-175 g) were purchased from Janvier (St Berthevin, France). All animals were housed 3 per cage in a temperature-controlled room (222 C.) and 505% relative humidity with a 12 hour light/12 hour dark photoperiod (lights off at 6 h00 pm). The animals were allowed 2 weeks of postoperative recovery prior to study. Animals were handled on a daily basis. Standard diet and tap water were provided ad libitum. Animal cage litters were changed once a week. On the study day, animals were acclimated to the procedure room for a period of one hour prior to the initiation of the experiment.
Compounds of the invention were formulated as 10% DMSO, 10% Cremophore EL, and 80% saline solutions.
After basal sampling (T0) a single dose of compounds of the invention or vehicle was administrated intravenously to rats. Blood was then collected at 60 min and 120 min post dosing. Blood samples were obtained via tail vein bleed, drawn into EDTA-containing tubes and centrifuged immediately. Plasma samples were collected and stored in a 80 C. freezer until assayed. Serum LH levels were determined using radioimmunoassay kit from IDS (Lige, Belgium). Baseline was defined as the initial basal blood sample.
When tested in the castrated male rat model described above, the compounds n.sup.o 144, 71, 156 and 114 significantly suppressed GnRH-mediated elevation of LH (FIGS. 1 and 2).
This result also shows that the compounds according to the invention pass through the blood-brain barrier and that they are capable of blocking the action of the NK-3 receptors in the CNS. The brain to plasma ratio values (B/P) obtained with the compounds according to the invention were generally greater than 0.1 indicating a significant brain penetration.
Gonad-Intact Adult Male to Assess the Effect of Compounds of the Invention on Circulating Levels of Testosterone.
Gonad-intact adult male Sprague-Dawley (SD) rats (300-385 g N=5/group were single housed in a temperature-controlled room (222 C.) and 505% relative humidity with a 12 hour light/12 hour dark photoperiod (lights off at 6 h00 pm). Purina rat chow (Ralston Purina Co., St. Louis, Mo.) and tap water were made available to rats, ad libitum. Chronic intracardiac venous cannulae were implanted under sodium pentobarbital anaesthesia (50 mg/kg, i.p.). After surgery, rats were placed directly into isolation test chambers and provided with food and water ad libitum until body weight returned to preoperative levels (a period of at least five days). On the test day, food was removed 1.5 h before the start of sampling and was returned at the end of the experiment. After basal blood sampling, free-moving rats were intravenously injected at time=0 min with either a single dose (20 mg/kg) of compound n.sup.o 156 or vehicle. Blood was then collected through a heparinized line at regular intervals up to 420 min and centrifuged immediately. Plasma samples were collected and stored in a 80 C. freezer until assayed. Plasma testosterone levels were determined using a radioimmunoassay kit (Immunotech).
Compound n.sup.o 156 was formulated as 40% DMA, 50% PEG400, and 10% sterile water solution.
When tested in gonad-intact male rats, compound n.sup.o 156 significantly suppressed plasma testosterone levels over the 420 minute test period (FIG. 3).