5-Substituted-2-arylpyrazines

Abstract

Novel 5-substituted-2-arylpyrazine compounds are provided. Such compounds can act as selective modulators of CRF receptors. The 5-substituted-2-arylpyrazine compounds provided herein are useful in the treatment of a number of CNS and periphereal disorders, particularly stress, anxiety, depression, cardiovascular disorders, and eating disorders. Methods of treatment of such disorders and well as packaged pharmaceutical compositions are also provided. Compounds provided are also useful as probes for the localization of CRF receptors and as standards in assays for CRF receptor binding. Methods of using the compounds in receptor localization studies are given.

1 - 25 . (canceled)  
   
   
       26 . A compound selected from 
 2-(2,6-dimethoxypyridin-3-yl)-3,6-diethyl-5-(1-ethylpropoxy)pyrazine;    2-(2,6-dimethoxypyridin-3-yl)-3,6-diethyl-5-(1-isopropyl-2-methylpropoxy)pyrazine;    5-[3,6-diethyl-5-(1-isopropyl-2-methylpropoxy)pyrazin-2-yl]-6-methoxy-N,N-dimethylpyridin-2-amine;    3-(1-ethylpropoxy)-6-(6-isopropyl-2-methoxypyridin-3-yl)-N,5-dimethylpyrazin-2-amine;    5-ethyl-3-(1-ethylpropoxy)-6-(6-isopropyl-2-methoxypyridin-3-yl)-N-methylpyrazin-2-amine;    5-[6-(dimethylamino)-2-ethylpyridin-3-yl]-N-(1-ethylpropyl)-3-methoxy-6-methylpyrazin-2-amine;    6-(2,6-dimethoxypyridin-3-yl)-3-[(1-ethylpropyl)amino]-5-methylpyrazine-2-carbonitrile;    5-[6-(dimethylamino)-2-ethylpyridin-3-yl]-6-ethyl-N-(1-ethylpropyl)-3-methoxypyrazin-2-amine;    5-[6-(dimethylamino)-2-ethylpyridin-3-yl]-N-(1-ethylpropyl)-6-methyl-3-(methylthio)pyrazin-2-amine;    5-[6-(dimethylamino)-2,4-dimethylpyridin-3-yl]-N-(1-ethylpropyl)-3-methoxy-6-methylpyrazin-2-amine;    N-(1-ethylpropyl)-5-(6-isopropyl-2-methoxypyridin-3-yl)-3-methoxypyrazin-2-amine;    5-bromo-3-(1-ethylpropoxy)-6-(6-isopropyl-2-methoxypyridin-3-yl)-N-methylpyrazin-2-amine;    2,5-diethyl-3-(1-ethylpropoxy)-6-(6-isopropyl-2-methoxypyridin-3-yl)pyrazine;    5-(2,4-dimethoxypyrimidin-5-yl)-N-(1-ethylpropyl)-3-methoxy-6-methylpyrazin-2-amine;    5-(2,4-dimethoxypyrimidin-5-yl)-6-ethyl-N-(1-ethylpropyl)-3-methoxypyrazin-2-amine;    N-(1-ethylpropyl)-5-(6-isopropyl-2-methoxypyridin-3-yl)-6-methyl-3-(methylthio)pyrazin-2-amine;    2,5-diethyl-3-(1-ethylbutoxy)-6-(6-isopropyl-2-methoxypyridin-3-yl)pyrazine;    5-[6-(dimethylamino)-2-methoxypyridin-3-yl]-N-(1-ethylpropyl)-3-methoxy-6-methylpyrazin-2-amine;    5-(2,6-dimethoxypyridin-3-yl)-N-(1-ethylpropyl)-3-methoxy-6-methylpyrazin-2-amine;    5-(2,6-dimethoxypyridin-3-yl)-6-ethyl-N-(1-ethylpropyl)-3-methoxypyrazin-2-amine;    2,5-diethyl-3-(1-ethylpropoxy)-6-[2-methoxy-6-(trifluoromethyl)pyridin-3-yl]pyrazine;    5-(2-chloro-6-isopropylpyridin-3-yl)-6-ethyl-N-(1-ethylpropyl)-3-methoxypyrazin-2-amine;    N 2 -(1 ethylpropyl)-5-[2-methoxy-6-(trifluoromethyl)pyridin-3-yl]-6-methylpyrazine-2,3-diamine;    N-(1-ethylpropyl)-3-methoxy-5-[2-methoxy-6-(trifluoromethyl)pyridin-3-yl]-6-methylpyrazin-2-amine;    6-ethyl-N-(1-ethylpropyl)-3-methoxy-5-[2-methoxy-6-(trifluoromethyl)pyridin-3-yl]pyrazin-2-amine;    N-(1-ethylpropyl)-5-(6-isopropyl-2-methoxypyridin-3-yl)-3-methoxy-6-methylpyrazin-2-amine;    6-ethyl-N-(1-ethylpropyl)-5-(6-isopropyl-2-methoxypyridin-3-yl)-3-methoxypyrazin-2-amine;    N-(1-ethylpropyl)-3-methoxy-5-(2-methoxy-6-pyrrolidin-1-ylpyridin-3-yl)-6-methylpyrazin-2-amine;    6-ethyl-N-(1-ethylpropyl)-3-methoxy-5-(2-methoxy-6-pyrrolidin-1-ylpyridin-3-yl)pyrazin-2-amine;    5-[6-(dimethylamino)-2-methylpyridin-3-yl]-N-(1-ethylpropyl)-3-methoxy-6-methylpyrazin-2-amine;    N-(1-ethylpropyl)-5-[2-methoxy-6-(trifluoromethyl)pyridin-3-yl]-6-methyl-3-(methylthio)pyrazin-2-amine;    5-(2,6-dimethoxypyridin-3-yl)-N-(1-ethylpropyl)-6-methyl-3-(methylthio)pyrazin-2-amine;    or a pharmaceutically acceptable salt thereof.    
   
   
       27 . A compound selected from: 
 [6-(6-Dimethylamino-4-ethyl-2-methyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    [6-(6-Dimethylamino-2,4-dimethyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    [5-Ethyl-6-[2-(ethyl-methyl-amino)-6-isopropyl-pyridin-3-yl]-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    2-({3-[3-Ethyl-5-(1-ethyl-propoxy)-6-methylamino-pyrazin-2-yl]-6-isopropyl-pyridin-2-yl}-methyl-amino)-ethanol;    [5-Ethyl-3-(1-ethyl-propoxy)-6-(6-isopropyl-2-morpholin-4-yl-pyridin-3-yl)-pyrazin-2-yl]-methyl-amine;    [5-Ethyl-3-(1-ethyl-propoxy)-6-(6-isopropyl-2-pyrrolidin-1-yl-pyridin-3-yl)-pyrazin-2-yl]-methyl-amine;    {5-Ethyl-3-(1-ethyl-propoxy)-6-[6-isopropyl-2-(2-methoxy-ethylamino)-pyridin-3-yl]-pyrazin-2-yl}-methyl-amine;    [5-Ethyl-6-(5-ethyl-6-isopropylamino-2-methyl-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    [5-Ethyl-3-(1-ethyl-propoxy)-6-(6-isopropyl-2-methylamino-pyridin-3-yl)-pyrazin-2-yl]-methyl-amine;    [5-Ethyl-6-(2-ethylamino-6-isopropyl-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    [5-Ethyl-3-(1-ethyl-propoxy)-6-(6-isopropyl-2-isopropylamino-pyridin-3-yl)-pyrazin-2-yl]-methyl-amine;    [5-Ethyl-3-(1-ethyl-propoxy)-6-(6′-isopropyl-3,4,5,6-tetrahydro-2H-[1,2′]bipyridinyl-3′-yl)-pyrazin-2-yl]-methyl-amine;    3-{3-[3-Ethyl-5-(1-ethyl-propoxy)-6-methylamino-pyrazin-2-yl]-6-isopropyl-pyridin-2-ylamino}-propan-1-ol;    [6-(2-Azetidin-1-yl-5-bromo-6-isopropyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    [6-(2-Azetidin-1-yl-5-ethyl-6-isopropyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    {5-Ethyl-3-(1-ethyl-propoxy)-6-[6-isopropyl-2-(4-methyl-piperazin-1-yl)-pyridin-3-yl]-pyrazin-2-yl}-methyl-amine;    Trifluoro-methanesulfonic acid 5-[3-ethyl-5-(1-ethyl-propoxy)-6-methylamino-pyrazin-2-yl]-6-methyl-pyridin-2-yl ester;    [5-Ethyl-6-(5-ethyl-6-isopropyl-2-pyrrolidin-1-yl-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    2-(4-{3-[3-Ethyl-5-(1-ethyl-propoxy)-6-methylamino-pyrazin-2-yl]-6-isopropyl-pyridin-2-yl}-piperazin-1-yl)-ethanol;    N1-{3-[3-Ethyl-5-(1-ethyl-propoxy)-6-methylamino-pyrazin-2-yl]-6-isopropyl-pyridin-2-yl}-N1-methyl-ethane-1,2-diamine;    2-{3-[3-Ethyl-5-(1-ethyl-propoxy)-6-methylamino-pyrazin-2-yl]-6-isopropyl-pyridin-2-yloxy}-acetamide;    2-{3-[3-Ethyl-5-(1-ethyl-propoxy)-6-methylamino-pyrazin-2-yl]-6-isopropyl-pyridin-2-yloxy}-ethanol;    [5-Ethyl-3-(1-ethyl-propoxy)-6-(6-isopropyl-2-piperazin-1-yl-pyridin-3-yl)-pyrazin-2-yl]-methyl-amine;    [5-Ethyl-3-(1-ethyl-propoxy)-6-(2-methyl-6-morpholin-4-yl-pyridin-3-yl)-pyrazin-2-yl]-methyl-amine;    5-[3-Ethyl-5-(1-ethyl-propoxy)-6-methylamino-pyrazin-2-yl]-6-methyl-pyridine-2-carbonitrile;    [5-Ethyl-6-(5-ethyl-2-methyl-6-morpholin-4-yl-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    [6-(5-Bromo-6-dimethylamino-2-methyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    N2-(1-Ethyl-propyl)-5-(6-isopropyl-2-methoxy-pyridin-3-yl)-6-methyl-pyrazine-2,3-diamine;    [5-(6-Dimethylamino-2-ethyl-pyridin-3-yl))-3-ethyl-6-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [3-Bromo-5-(6-dimethylamino-5-methoxymethyl-2-methyl-pyridin-3-yl)-6-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [5-(6-Dimethylamino-5-methoxymethyl-2-methyl-pyridin-3-yl)-3-ethyl-6-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [3,6-Diethyl-5-(6-isopropyl-2-methoxy-pyridin-3-yl)-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    1-{3-[3,6-Diethyl-5-(1-ethyl-propylamino)-pyrazin-2-yl]-6-isopropyl-pyridin-2-ylamino}-propan-2-ol;    3-{3-[3,6-Diethyl-5-(1-ethyl-propylamino)-pyrazin-2-yl]-6-isopropyl-pyridin-2-ylamino}-propan-1-ol;    2-{3-[3,6-Diethyl-5-(1-ethyl-propylamino)-pyrazin-2-yl]-6-isopropyl-pyridin-2-ylamino}-ethanol;    [3-Ethyl-5-(6-isopropyl-2-methoxy-pyridin-3-yl)-6-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    1-{2-Dimethylamino-5-[6-ethyl-5-(1-ethyl-propylamino)-3-methoxy-pyrazin-2-yl]-6-methyl-pyridin-3-yl}-ethanol;    [3,6-Diethyl-5-(6-isopropyl-2-methylamino-pyridin-3-yl)-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [6-Chloro-3-ethyl-5-(6-isopropyl-2-methoxy-pyridin-3-yl)-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [3,6-Diethyl-5-(6-ethyl-2-methoxy-pyridin-3-yl)-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [6-Chloro-3-ethyl-5-(6-isopropyl-2-methylamino-pyridin-3-yl)-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [3,6-Diethyl-5-(2-ethyl-6-isopropyl-pyridin-3-yl)-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [3-Ethyl-5-(6-isopropyl-2-methoxy-pyridin-3-yl)-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [3-Ethyl-5-(2-ethyl-6-isopropyl-pyridin-3-yl)-6-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [5-(2-Ethyl-6-isopropyl-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    2-{3-[5-(1-Ethyl-propylamino)-6-methoxy-3-methyl-pyrazin-2-yl]-6-isopropyl-pyridin-2-ylamino}-ethanol;    3-{3-[5-(1-Ethyl-propylamino)-6-methoxy-3-methyl-pyrazin-2-yl]-6-isopropyl-pyridin-2-ylamino}-propan-1-ol;    (1-Ethyl-propyl)-[5-(6-isopropyl-2-morpholin-4-yl-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-amine;    (1-Ethyl-propyl)-{5-[6-isopropyl-2-(2-methoxy-ethylamino)-pyridin-3-yl]-3-methoxy-6-methyl-pyrazin-2-yl}-amine;    (1-Ethyl-propyl)-{5-[6-isopropyl-2-(3-morpholin-4-yl-propylamino)-pyridin-3-yl]-3-methoxy-6-methyl-pyrazin-2-yl}-amine;    (1-Ethyl-propyl)-[5-(6-isopropyl-2-methylamino-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-amine;    [3-Ethoxy-5-(2-methoxy-4-trifluoromethoxy-phenyl)-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [3-Ethyl-5-(2-ethyl-6-isopropyl-pyridin-3-yl)-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [3-Ethyl-5-(6-isopropyl-2-methylamino-pyridin-3-yl)-6-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    3-{3-[6-Ethyl-5-(1-ethyl-propylamino)-3-methoxy-pyrazin-2-yl]-6-isopropyl-pyridin-2-ylamino}-propan-1-ol;    6-Ethyl-5-[6-ethyl-5-(1-ethyl-propylamino)-3-methyl-pyrazin-2-yl]-2-isopropyl-2H-pyridin-1-ol;    N-{3-[5-(1-Ethyl-propylamino)-6-methoxy-3-methyl-pyrazin-2-yl]-6-isopropyl-pyridin-2-yl}-N′,N′-dimethyl-propane-1,3-diamine;    [6-Ethyl-5-(2-ethyl-6-isopropyl-pyridin-3-yl)-3-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [3-Bromo-5-(6-isopropyl-2-methoxy-pyridin-3-yl)-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [6-Ethyl-5-(6-isopropyl-2-methylamino-pyridin-3-yl)-3-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    3-{3-[3-Ethyl-5-(1-ethyl-propylamino)-6-methoxy-pyrazin-2-yl]-6-isopropyl-pyridin-2-ylamino}-propan-1-ol;    {6-Ethyl-5-[6-isopropyl-2-(3-morpholin-4-yl-propylamino)-pyridin-3-yl]-3-methoxy-pyrazin-2-yl}-(1-ethyl-propyl)-amine;    [5-(2-Ethyl-6-isopropoxy-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [6-Ethyl-5-(6-isopropyl-2-methyl-pyridin-3-yl)-3-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    (1-Ethyl-propyl)-[5-(6-isopropyl-2-methyl-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-amine;    (1-Ethyl-butyl)-[5-(2-ethyl-6-isopropyl-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-amine;    (1-Ethyl-butyl)-[5-(6-isopropyl-2-methylamino-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-amine;    [5-(2-Ethylamino-6-isopropyl-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [5-(2-Dimethylamino-6-isopropyl-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    (1-Ethyl-butyl)-{5-[6-isopropyl-2-(3-morpholin-4-yl-propylamino)-pyridin-3-yl]-3-methoxy-6-methyl-pyrazin-2-yl}-amine;    [5-(5-Ethyl-6-methoxy-2-methyl-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine;    [5-Methyl-6-(5-ethyl-6-methoxy-2-methyl-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    [5-Ethyl-6-(5-ethyl-6-methoxy-2-methyl-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    [5-Ethyl-6-(2-ethyl-6-isopropoxy-2-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    [5-Ethyl-6-(2-ethoxy-6-isopropoxy-2-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    [5-Ethyl-6-(2-methyl-6-isopropyl-2-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    [5-Ethyl-6-(2-hydroxy-6-isopropyl-2-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    [5-Ethyl-6-(2-methyl-6-dimethylamino-2-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    [5-Ethyl-6-(2-dimethylamino-6-isopropyl-2-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    [6-(2-methyl-6-isopropyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine    [6-(2-Azetidin-1-yl-6-isopropyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    [6-(2-Diethylamino-6-isopropyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine;    [3-(1-Ethyl-propoxy)-6-(6-isopropylamino-2-methyl-5-bromo-pyridin-3-yl)-5-bromo-pyrazin-2-yl]-methyl-amine;    [6-(6-Dimethylamino-5-ethyl-2-methyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine; and    [3-(1-Ethyl-propoxy)-6-(6-isopropylamino-2,5-dimethyl-pyridin-3-yl)-5-methyl-pyrazin-2-yl]-methyl-amine.    
   
   
       28 . A method for treating anxiety, depression, or stress comprising administering to a patient in need of such treatment a therapeutically effective amount of a compound or salt according to  claim 26 .  
   
   
       29 . A method for treating irritable bowel syndrome or Crohn's disease, comprising administering to a patient in need of such treatment a therapeutically effective amount of a compound or salt according to  claim 26 .  
   
   
       30 . A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a compound or salt of  claim 26 .  
   
   
       31 . A pharmaceutical composition according to  claim 30 , wherein the composition is formulated as an injectable fluid, an aerosol, a cream, a gel, a tablet, a pill, a capsule, a syrup or a transdermal patch.  
   
   
       32 . The compound of  claim 26 , wherein the compound is 2-(2,6-dimethoxypyridin-3-yl)-3,6-diethyl-5-(1-ethylpropoxy)pyrazine or a pharmaceutically acceptable salt thereof.  
   
   
       33 . The compound of  claim 26 , wherein the compound is 2-(2,6-dimethoxypyridin-3-yl)-3,6-diethyl-5-(1-isopropyl-2-methylpropoxy)pyrazine or a pharmaceutically acceptable salt thereof.  
   
   
       34 . The compound of  claim 26 , wherein the compound is 5-[3,6-diethyl-5-(1-isopropyl-2-methylpropoxy)pyrazin-2-yl]-6-methoxy-N,N-dimethylpyridin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       35 . The compound of  claim 26 , wherein the compound is 3-(1-ethylpropoxy)-6-(6-isopropyl-2-methoxypyridin-3-yl)-N,5-dimethylpyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       36 . The compound of  claim 26 , wherein the compound is 5-ethyl-3-(1-ethylpropoxy)-6-(6-isopropyl-2-methoxypyridin-3-yl)-N-methylpyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       37 . The compound of  claim 26 , wherein the compound is 5-[6-(dimethylamino)-2-ethylpyridin-3-yl]-N-(1-ethylpropyl)-3-methoxy-6-methylpyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       38 . The compound of  claim 26 , wherein the compound is 6-(2,6-dimethoxypyridin-3-yl)-3-[(1-ethylpropyl)amino]-5-methylpyrazine-2-carbonitrile or a pharmaceutically acceptable salt thereof.  
   
   
       39 . The compound of  claim 26 , wherein the compound is 5-[6-(dimethylamino)-2-ethylpyridin-3-yl]-6-ethyl-N-(1-ethylpropyl)-3-methoxypyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       40 . The compound of  claim 26 , wherein the compound is 5-[6-(dimethylamino)-2-ethylpyridin-3-yl]-N-(1-ethylpropyl)-6-methyl-3-(methylthio)pyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       41 . The compound of  claim 26 , wherein the compound is 5-[6-(dimethylamino)-2,4-dimethylpyridin-3-yl]-N-(1-ethylpropyl)-3-methoxy-6-methylpyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       42 . The compound of  claim 26 , wherein the compound is N-(1-ethylpropyl)-5-(6-isopropyl-2-methoxypyridin-3-yl)-3-methoxypyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       43 . The compound of  claim 26 , wherein the compound is 5-bromo-3-(1-ethylpropoxy)-6-(6-isopropyl-2-methoxypyridin-3-yl)-N-methylpyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       44 . The compound of  claim 26 , wherein the compound is 2,5-diethyl-3-(1-ethylpropoxy)-6-(6-isopropyl-2-methoxypyridin-3-yl)pyrazine or a pharmaceutically acceptable salt thereof.  
   
   
       45 . The compound of  claim 26 , wherein the compound is 5-(2,4-dimethoxypyrimidin-5-yl)-N-(1-ethylpropyl)-3-methoxy-6-methylpyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       46 . The compound of  claim 26 , wherein the compound is 5-(2,4-dimethoxypyrimidin-5-yl)-6-ethyl-N-(1-ethylpropyl)-3-methoxypyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       47 . The compound of  claim 26 , wherein the compound is N-(1-ethylpropyl)-5-(6-isopropyl-2-methoxypyridin-3-yl)-6-methyl-3-(methylthio)pyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       48 . The compound of  claim 26 , wherein the compound is 2,5-diethyl-3-(1-ethylbutoxy)-6-(6-isopropyl-2-methoxypyridin-3-yl)pyrazine or a pharmaceutically acceptable salt thereof.  
   
   
       49 . The compound of  claim 26 , wherein the compound is 5-[6-(dimethylamino)-2-methoxypyridin-3-yl]-N-(1-ethylpropyl)-3-methoxy-6-methylpyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       50 . The compound of  claim 26 , wherein the compound is 5-(2,6-dimethoxypyridin-3-yl)-N-(1-ethylpropyl)-3-methoxy-6-methylpyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       51 . The compound of  claim 26 , wherein the compound is 5-(2,6-dimethoxypyridin-3-yl)-6-ethyl-N-(1-ethylpropyl)-3-methoxypyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       52 . The compound of  claim 26 , wherein the compound is 2,5-diethyl-3-(1-ethylpropoxy)-6-[2-methoxy-6-(trifluoromethyl)pyridin-3-yl]pyrazine or a pharmaceutically acceptable salt thereof.  
   
   
       53 . The compound of  claim 26 , wherein the compound is 5-(2-chloro-6-isopropylpyridin-3-yl)-6-ethyl-N-(1-ethylpropyl)-3-methoxypyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       54 . The compound of  claim 26 , wherein the compound is N 2 -(1-ethylpropyl)-5-[2-methoxy-6-(trifluoromethyl)pyridin-3-yl]-6-methylpyrazine-2,3-diamine or a pharmaceutically acceptable salt thereof.  
   
   
       55 . The compound of  claim 26 , wherein the compound is N-(1-ethylpropyl)-3-methoxy-5-[2-methoxy-6-(trifluoromethyl)pyridin-3-yl]-6-methylpyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       56 . The compound of  claim 26 , wherein the compound is 6-ethyl-N-(1-ethylpropyl)-3-methoxy-5-[2-methoxy-6-(trifluoromethyl)pyridin-3-yl]pyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       57 . The compound of  claim 26 , wherein the compound is N-(1-ethylpropyl)-5-(6-isopropyl-2-methoxypyridin-3-yl)-3-methoxy-6-methylpyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       58 . The compound of  claim 26 , wherein the compound is 6-ethyl-N-(1-ethylpropyl)-5-(6-isopropyl-2-methoxypyridin-3-yl)-3-methoxypyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       59 . The compound of  claim 26 , wherein the compound is N-(1-ethylpropyl)-3-methoxy-5-(2-methoxy-6-pyrrolidin-1-ylpyridin-3-yl)-6-methylpyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       60 . The compound of  claim 26 , wherein the compound is 6-ethyl-N-(1-ethylpropyl)-3-methoxy-5-(2-methoxy-6-pyrrolidin-1-ylpyridin-3-yl)pyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       61 . The compound of  claim 26 , wherein the compound is 5-[6-(dimethylamino)-2-methylpyridin-3-yl]-N-(1-ethylpropyl)-3-methoxy-6-methylpyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       62 . The compound of  claim 26 , wherein the compound is N-(1-ethylpropyl)-5-[2-methoxy-6-(trifluoromethyl)pyridin-3-yl]-6-methyl-3-(methylthio)pyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       63 . The compound of  claim 26 , wherein the compound is 5-(2,6-dimethoxypyridin-3-yl)-N-(1-ethylpropyl)-6-methyl-3-(methylthio)pyrazin-2-amine or a pharmaceutically acceptable salt thereof.  
   
   
       64 . The compound of  claim 27 , wherein the compound is [6-(6-Dimethylamino-4-ethyl-2-methyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       65 . The compound of  claim 27 , wherein the compound is [6-(6-Dimethylamino-2,4-dimethyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       66 . The compound of  claim 27 , wherein the compound is [5-Ethyl-6-[2-(ethyl-methyl-amino)-6-isopropyl-pyridin-3-yl]-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       67 . The compound of  claim 27 , wherein the compound is 2-({3-[3-Ethyl-5-(1-ethyl-propoxy)-6-methylamino-pyrazin-2-yl]-6-isopropyl-pyridin-2-yl}-methyl-amino)-ethanol or a pharmaceutically acceptable salt thereof.  
   
   
       68 . The compound of  claim 27 , wherein the compound is [5-Ethyl-3-(1-ethyl-propoxy)-6-(6-isopropyl-2-morpholin-4-yl-pyridin-3-yl)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       69 . The compound of  claim 27 , wherein the compound is [5-Ethyl-3-(1-ethyl-propoxy)-6-(6-isopropyl-2-pyrrolidin-1-yl-pyridin-3-yl)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       70 . The compound of  claim 27 , wherein the compound is {5-Ethyl-3-(1-ethyl-propoxy)-6-[6-isopropyl-2-(2-methoxy-ethylamino)-pyridin-3-yl]-pyrazin-2-yl}-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       71 . The compound of  claim 27 , wherein the compound is [5-Ethyl-6-(5-ethyl-6-isopropylamino-2-methyl-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       72 . The compound of  claim 27 , wherein the compound is [5-Ethyl-3-(1-ethyl-propoxy)-6-(6-isopropyl-2-methylamino-pyridin-3-yl)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       73 . The compound of  claim 27 , wherein the compound is [5-Ethyl-6-(2-ethylamino-6-isopropyl-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       74 . The compound of  claim 27 , wherein the compound is [5-Ethyl-3-(1-ethyl-propoxy)-6-(6-isopropyl-2-isopropylamino-pyridin-3-yl)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       75 . The compound of  claim 27 , wherein the compound is [5-Ethyl-3-(1-ethyl-propoxy)-6-(6′-isopropyl-3,4,5,6-tetrahydro-2H-[1,2′]bipyridinyl-3′-yl)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       76 . The compound of  claim 27 , wherein the compound is 3-{3-[3-Ethyl-5-(1-ethyl-propoxy)-6-methylamino-pyrazin-2-yl]-6-isopropyl-pyridin-2-ylamino}-propan-1-ol or a pharmaceutically acceptable salt thereof.  
   
   
       77 . The compound of  claim 27 , wherein the compound is [6-(2-Azetidin-1-yl-5-bromo-6-isopropyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       78 . The compound of  claim 27 , wherein the compound is [6-(2-Azetidin-1-yl-5-ethyl-6-isopropyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       79 . The compound of  claim 27 , wherein the compound is {5-Ethyl-3-(1-ethyl-propoxy)-6-[6-isopropyl-2-(4-methyl-piperazin-1-yl)-pyridin-3-yl]-pyrazin-2-yl}-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       80 . The compound of  claim 27 , wherein the compound is Trifluoro-methanesulfonic acid 5-[3-ethyl-5-(1-ethyl-propoxy)-6-methylamino-pyrazin-2-yl]-6-methyl-pyridin-2-yl ester or a pharmaceutically acceptable salt thereof.  
   
   
       81 . The compound of  claim 27 , wherein the compound is [5-Ethyl-6-(5-ethyl-6-isopropyl-2-pyrrolidin-1-yl-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       82 . The compound of  claim 27 , wherein the compound is 2-(4-{3-[3-Ethyl-5-(1-ethyl-propoxy)-6-methylamino-pyrazin-2-yl]-6-isopropyl-pyridin-2-yl}-piperazin-1-yl)-ethanol or a pharmaceutically acceptable salt thereof.  
   
   
       83 . The compound of  claim 27 , wherein the compound is N1-{3-[3-Ethyl-5-(1-ethyl-propoxy)-6-methylamino-pyrazin-2-yl]-6-isopropyl-pyridin-2-yl}-N1-methyl-ethane-1,2-diamine or a pharmaceutically acceptable salt thereof.  
   
   
       84 . The compound of  claim 27 , wherein the compound is 2-{3-[3-Ethyl-5-(1-ethyl-propoxy)-6-methylamino-pyrazin-2-yl]-6-isopropyl-pyridin-2-yloxy}-acetamide or a pharmaceutically acceptable salt thereof.  
   
   
       85 . The compound of  claim 27 , wherein the compound is 2-{3-[3-Ethyl-5-(1-ethyl-propoxy)-6-methylamino-pyrazin-2-yl]-6-isopropyl-pyridin-2-yloxy}-ethanol or a pharmaceutically acceptable salt thereof.  
   
   
       86 . The compound of  claim 27 , wherein the compound is [5-Ethyl-3-(1-ethyl-propoxy)-6-(6-isopropyl-2-piperazin-1-yl-pyridin-3-yl)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       87 . The compound of  claim 27 , wherein the compound is [5-Ethyl-3-(1-ethyl-propoxy)-6-(2-methyl-6-morpholin-4-yl-pyridin-3-yl)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       88 . The compound of  claim 27 , wherein the compound is 5-[3-Ethyl-5-(1-ethyl-propoxy)-6-methylamino-pyrazin-2-yl]-6-methyl-pyridine-2-carbonitrile or a pharmaceutically acceptable salt thereof.  
   
   
       89 . The compound of  claim 27 , wherein the compound is [5-Ethyl-6-(5-ethyl-2-methyl-6-morpholin-4-yl-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       90 . The compound of  claim 27 , wherein the compound is [6-(5-Bromo-6-dimethylamino-2-methyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       91 . The compound of  claim 27 , wherein the compound is N2-(1-Ethyl-propyl)-5-(6-isopropyl-2-methoxy-pyridin-3-yl)-6-methyl-pyrazine-2,3-diamine or a pharmaceutically acceptable salt thereof.  
   
   
       92 . The compound of  claim 27 , wherein the compound is [5-(6-Dimethylamino-2-ethyl-pyridin-3-yl)-3-ethyl-6-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       93 . The compound of  claim 27 , wherein the compound is [3-Bromo-5-(6-dimethylamino-5-methoxymethyl-2-methyl-pyridin-3-yl)-6-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       94 . The compound of  claim 27 , wherein the compound is [5-(6-Dimethylamino-5-methoxymethyl-2-methyl-pyridin-3-yl)-3-ethyl-6-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       95 . The compound of  claim 27 , wherein the compound is [3,6-Diethyl-5-(6-isopropyl-2-methoxy-pyridin-3-yl)-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       96 . The compound of  claim 27 , wherein the compound is 1-{3-[3,6-Diethyl-5-(1-ethyl-propylamino)-pyrazin-2-yl]-6-isopropyl-pyridin-2-ylamino}-propan-2-ol or a pharmaceutically acceptable salt thereof.  
   
   
       97 . The compound of  claim 27 , wherein the compound is 3-{3-[3,6-Diethyl-5-(1-ethyl-propylamino)-pyrazin-2-yl]-6-isopropyl-pyridin-2-ylamino}-propan-1-ol or a pharmaceutically acceptable salt thereof.  
   
   
       98 . The compound of  claim 27 , wherein the compound is 2-{3-[3,6-Diethyl-5-(1-ethyl-propylamino)-pyrazin-2-yl]-6-isopropyl-pyridin-2-ylamino}-ethanol or a pharmaceutically acceptable salt thereof.  
   
   
       99 . The compound of  claim 27 , wherein the compound is [3-Ethyl-5-(6-isopropyl-2-methoxy-pyridin-3-yl)-6-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       100 . The compound of  claim 27 , wherein the compound is 1-{2-Dimethylamino-5-[6-ethyl-5-(1-ethyl-propylamino)-3-methoxy-pyrazin-2-yl]-6-methyl-pyridin-3-yl}-ethanol or a pharmaceutically acceptable salt thereof.  
   
   
       101 . The compound of  claim 27 , wherein the compound is [3,6-Diethyl-5-(6-isopropyl-2-methylamino-pyridin-3-yl)-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       102 . The compound of  claim 27 , wherein the compound is [6-Chloro-3-ethyl-5-(6-isopropyl-2-methoxy-pyridin-3-yl)-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       103 . The compound of  claim 27 , wherein the compound is [3,6-Diethyl-5-(6-ethyl-2-methoxy-pyridin-3-yl)-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       104 . The compound of  claim 27 , wherein the compound is [6-Chloro-3-ethyl-5-(6-isopropyl-2-methylamino-pyridin-3-yl)-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       105 . The compound of  claim 27 , wherein the compound is [3,6-Diethyl-5-(2-ethyl-6-isopropyl-pyridin-3-yl)-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       106 . The compound of  claim 27 , wherein the compound is [3-Ethyl-5-(6-isopropyl-2-methoxy-pyridin-3-yl)-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       107 . The compound of  claim 27 , wherein the compound is [3-Ethyl-5-(2-ethyl-6-isopropyl-pyridin-3-yl)-6-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       108 . The compound of  claim 27 , wherein the compound is [5-(2-Ethyl-6-isopropyl-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       109 . The compound of  claim 27 , wherein the compound is 2-{3-[5-(1-Ethyl-propylamino)-6-methoxy-3-methyl-pyrazin-2-yl]-6-isopropyl-pyridin-2-ylamino}-ethanol or a pharmaceutically acceptable salt thereof.  
   
   
       110 . The compound of  claim 27 , wherein the compound is 3-{3-[5-(1-Ethyl-propylamino)-6-methoxy-3-methyl-pyrazin-2-yl]-6-isopropyl-pyridin-2-ylamino}-propan-1-ol or a pharmaceutically acceptable salt thereof.  
   
   
       111 . The compound of  claim 27 , wherein the compound is (1-Ethyl-propyl)-[5-(6-isopropyl-2-morpholin-4-yl-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-amine or a pharmaceutically acceptable salt thereof.  
   
   
       112 . The compound of  claim 27 , wherein the compound is (1-Ethyl-propyl)-{5-[6-isopropyl-2-(2-methoxy-ethylamino)-pyridin-3-yl]-3-methoxy-6-methyl-pyrazin-2-yl}-amine or a pharmaceutically acceptable salt thereof.  
   
   
       113 . The compound of  claim 27 , wherein the compound is (1-Ethyl-propyl)-{5-[6-isopropyl-2-(3-morpholin-4-yl-propylamino)-pyridin-3-yl]-3-methoxy-6-methyl-pyrazin-2-yl}-amine or a pharmaceutically acceptable salt thereof.  
   
   
       114 . The compound of  claim 27 , wherein the compound is (1-Ethyl-propyl)-[5-(6-isopropyl-2-methylamino-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-amine or a pharmaceutically acceptable salt thereof.  
   
   
       115 . The compound of  claim 27 , wherein the compound is [3-Ethoxy-5-(2-methoxy-4-trifluoromethoxy-phenyl)-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       116 . The compound of  claim 27 , wherein the compound is [3-Ethyl-5-(2-ethyl-6-isopropyl-pyridin-3-yl)-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       117 . The compound of  claim 27 , wherein the compound is [3-Ethyl-5-(6-isopropyl-2-methylamino-pyridin-3-yl)-6-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       118 . The compound of  claim 27 , wherein the compound is 3-{3-[6-Ethyl-5-(1-ethyl-propylamino)-3-methoxy-pyrazin-2-yl]-6-isopropyl-pyridin-2-ylamino}-propan-1-ol or a pharmaceutically acceptable salt thereof.  
   
   
       119 . The compound of  claim 27 , wherein the compound is 6-Ethyl-5-[6-ethyl-5-(1-ethyl-propylamino)-3-methyl-pyrazin-2-yl]-2-isopropyl-2H-pyridin-1-ol or a pharmaceutically acceptable salt thereof.  
   
   
       120 . The compound of  claim 27 , wherein the compound is N-{3-[5-(1-Ethyl-propylamino)-6-methoxy-3-methyl-pyrazin-2-yl]-6-isopropyl-pyridin-2-yl}-N′,N′-dimethyl-propane-1,3-diamine or a pharmaceutically acceptable salt thereof.  
   
   
       121 . The compound of  claim 27 , wherein the compound is [6-Ethyl-5-(2-ethyl-6-isopropyl-pyridin-3-yl)-3-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       122 . The compound of  claim 27 , wherein the compound is [3-Bromo-5-(6-isopropyl-2-methoxy-pyridin-3-yl)-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       123 . The compound of  claim 27 , wherein the compound is [6-Ethyl-5-(6-isopropyl-2-methylamino-pyridin-3-yl)-3-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       124 . The compound of  claim 27 , wherein the compound is 3-{3-[3-Ethyl-5-(1-ethyl-propylamino)-6-methoxy-pyrazin-2-yl]-6-isopropyl-pyridin-2-ylamino}-propan-1-ol or a pharmaceutically acceptable salt thereof.  
   
   
       125 . The compound of  claim 27 , wherein the compound is {6-Ethyl-5-[6-isopropyl-2-(3-morpholin-4-yl-propylamino)-pyridin-3-yl]-3-methoxy-pyrazin-2-yl}-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       126 . The compound of  claim 27 , wherein the compound is [5-(2-Ethyl-6-isopropoxy-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       127 . The compound of  claim 27 , wherein the compound is [6-Ethyl-5-(6-isopropyl-2-methyl-pyridin-3-yl)-3-methoxy-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       128 . The compound of  claim 27 , wherein the compound is (1-Ethyl-propyl)-[5-(6-isopropyl-2-methyl-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-amine or a pharmaceutically acceptable salt thereof.  
   
   
       129 . The compound of  claim 27 , wherein the compound is (1-Ethyl-butyl)-[5-(2-ethyl-6-isopropyl-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-amine or a pharmaceutically acceptable salt thereof.  
   
   
       130 . The compound of  claim 27 , wherein the compound is (1-Ethyl-butyl)-[5-(6-isopropyl-2-methylamino-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-amine or a pharmaceutically acceptable salt thereof.  
   
   
       131 . The compound of  claim 27 , wherein the compound is [5-(2-Ethylamino-6-isopropyl-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       132 . The compound of  claim 27 , wherein the compound is [5-(2-Dimethylamino-6-isopropyl-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       133 . The compound of  claim 27 , wherein the compound is (1-Ethyl-butyl)-{5-[6-isopropyl-2-(3-morpholin-4-yl-propylamino)-pyridin-3-yl]-3-methoxy-6-methyl-pyrazin-2-yl}-amine or a pharmaceutically acceptable salt thereof.  
   
   
       134 . The compound of  claim 27 , wherein the compound is [5-(5-Ethyl-6-methoxy-2-methyl-pyridin-3-yl)-3-methoxy-6-methyl-pyrazin-2-yl]-(1-ethyl-propyl)-amine or a pharmaceutically acceptable salt thereof.  
   
   
       135 . The compound of  claim 27 , wherein the compound is [5-Methyl-6-(5-ethyl-6-methoxy-2-methyl-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       136 . The compound of  claim 27 , wherein the compound is [5-Ethyl-6-(5-ethyl-6-methoxy-2-methyl-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       137 . The compound of  claim 27 , wherein the compound is [5-Ethyl-6-(2-ethyl-6-isopropoxy-2-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       138 . The compound of  claim 27 , wherein the compound is [5-Ethyl-6-(2-ethoxy-6-isopropoxy-2-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       139 . The compound of  claim 27 , wherein the compound is [5-Ethyl-6-(2-methyl-6-isopropyl-2-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       140 . The compound of  claim 27 , wherein the compound is [5-Ethyl-6-(2-hydroxy-6-isopropyl-2-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       141 . The compound of  claim 27 , wherein the compound is [5-Ethyl-6-(2-methyl-6-dimethylamino-2-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       142 . The compound of  claim 27 , wherein the compound is [5-Ethyl-6-(2-dimethylamino-6-isopropyl-2-pyridin-3-yl)-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       143 . The compound of  claim 27 , wherein the compound is [6-(2-methyl-6-isopropyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       144 . The compound of  claim 27 , wherein the compound is [6-(2-Azetidin-1-yl-6-isopropyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       145 . The compound of  claim 27 , wherein the compound is [6-(2-Diethylamino-6-isopropyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       146 . The compound of  claim 27 , wherein the compound is [3-(1-Ethyl-propoxy)-6-(6-isopropylamino-2-methyl-5-bromo-pyridin-3-yl)-5-bromo-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       147 . The compound of  claim 27 , wherein the compound is [6-(6-Dimethylamino-5-ethyl-2-methyl-pyridin-3-yl)-5-ethyl-3-(1-ethyl-propoxy)-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       148 . The compound of  claim 27 , wherein the compound is [3-(1-Ethyl-propoxy)-6-(6-isopropylamino-2,5-dimethyl-pyridin-3-yl)-5-methyl-pyrazin-2-yl]-methyl-amine or a pharmaceutically acceptable salt thereof.  
   
   
       149 . A method for treating anxiety, depression, or stress comprising administering to a patient in need of such treatment a therapeutically effective amount of a compound or salt according to  claim 27 .  
   
   
       150 . A method for treating irritable bowel syndrome or Crohn's disease, comprising administering to a patient in need of such treatment a therapeutically effective amount of a compound or salt according to  claim 27 .  
   
   
       151 . A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a compound or salt of  claim 27 .  
   
   
       152 . A pharmaceutical composition according to  claim 151 , wherein the composition is formulated as an injectable fluid, an aerosol, a cream, a gel, a tablet, a pill, a capsule, a syrup or a transdermal patch.