1-phenyl-2-pyridinyl alkyl alcohol compounds as phosphodiesterase inhibitors

Abstract

1-Phenyl-2-pyridinyl alkyl alcohol compounds are effective as inhibitors of the phosphodiesterase 4 (PDE4) enzyme and may be used to prevent and/or treat certain diseases or conditions.

1 . A compound of formula (I) as an (−) enantiomer 
       
         
           
           
               
               
           
         
         wherein: 
         n is 0 or 1; 
         R1 and R2 may be the same or different, and are selected from the group consisting of: 
         linear or branched C 1 -C 6  alkyl, optionally substituted by one or more halogen atoms; 
         —OR3 wherein R3 is a linear or branched C 1 -C 6  alkyl optionally substituted with one or more halogen atoms or C 3 -C 7  cycloalkyl groups; and 
         —NHSO 2 R4 wherein R4 is a linear or branched C 1 -C 4  alkyl optionally substituted with one or more halogen atoms, 
         wherein at least one of R1 and R2 is —NHSO 2 R4, 
         or a pharmaceutically acceptable salt thereof. 
       
     
     
         2 . A compound or a salt thereof according to  claim 1 , wherein R1 is —NHSO 2 R4, wherein R4 is methyl, R2 is —OR3, wherein R3 is cyclopropylmethyl, and n is 0. 
     
     
         3 . A compound or a salt thereof according to  claim 1 , wherein R1 is —NHSO 2 R4, wherein R4 is methyl, R2 is —OR3, wherein R3 is cyclopropylmethyl, and n is 1. 
     
     
         4 . A compound or a salt thereof according to  claim 1 , wherein R1 is —OR3, R2 is —NHSO 2 R4 wherein R4 is methyl, and n is 1. 
     
     
         5 . A compound or a salt thereof according to  claim 1 , wherein R1 is methyl, R2 is —NHSO 2 R4 wherein R4 is methyl, and n is 1. 
     
     
         6 . A compound or a salt thereof according to  claim 1 , wherein both R1 and R2 are —NHSO 2 R4, wherein R4 is methyl, and n is 0. 
     
     
         7 . A compound or a salt thereof according to  claim 1 , wherein both R1 and R2 are —NHSO 2 R4, wherein R4 is methyl, and n is 1. 
     
     
         8 . A process for the preparation of a compound or a salt thereof according to  claim 1 , comprising:
 (i) reacting an aldehyde of formula (1):   
       
         
           
           
               
               
           
         
         with methyldichloropyridine of formula (2): 
       
       
         
           
           
               
               
           
         
       
       to obtain aracemic alcohol of formula (3), which is optionally oxidized to the corresponding N-oxide compound of formula (4): 
       
         
           
           
               
               
           
         
         (ii) condensing a compound of formula (3) or (4) with a chiral acid selectd from the group consisting of (S)-naproxen or (S)-acetylmandelic acid to obtain, respectively, a diastereomeric mixture (10) or (5): 
       
       
         
           
           
               
               
           
         
         (iii) separating the diastereoisomeric mixture (10) or (5) into two single diastereoisomers of formulae (11) and (13) or formulae (6) and (8), respectively: 
       
       
         
           
           
               
               
           
         
       
       by chromatography, or crystallization, to obtain after cleavage, an alcohol of formula (14) or (+)(7) and (−)(9): 
       
         
           
           
               
               
           
         
         (iv) reacting compound (+)(14) or (+)(7) with a benzoic acid compound of formula (15): 
       
       
         
           
           
               
               
           
         
       
       to obtain said compound of formula (I) or salt thereof. 
     
     
         9 . A compound of formula (II): 
       
         
           
           
               
               
           
         
         wherein n is as defined in  claim 1  and the carbon atom represented with an asterisk has the (S) configuration, or a salt thereof. 
       
     
     
         10 . A combination of a compound of formula (I) or a salt according to  claim 1  with a second pharmaceutical active component selected from the group consisting of a β2 agonist, an M3 antagonist, and a corticosteroid. 
     
     
         11 . A combination according to  claim 10 , wherein said second active component is formoterol or carmoterol. 
     
     
         12 . A pharmaceutical composition, comprising a compound of formula (I) or a salt thereof according to  claim 1  and one or more pharmaceutically acceptable carriers and/or excipients. 
     
     
         13 . A pharmaceutical composition, comprising a combination according to  claim 10 , and one or more pharmaceutically acceptable carriers and/or excipients. 
     
     
         14 . A device, comprising a pharmaceutical composition according to  claim 12 . 
     
     
         15 . A device, comprising a pharmaceutical composition according to  claim 13 . 
     
     
         16 . A kit, comprising a pharmaceutical composition according of  claim 11  and a device which may be a single- or multi-dose dry powder inhaler, a metered dose inhaler or a soft mist nebulizer. 
     
     
         17 . A method of preventing and/or treating allergic rhinitis, comprising administering an effective amount of a compound of formula (I) or a salt thereof according to  claim 1  to a subject in need thereof. 
     
     
         18 . A method of preventing and/or treating atopic dermatitis, comprising administering an effective amount of a compound of formula (I) or a salt thereof according to  claim 1  to a subject in need thereof.