Ethers of O-Desmethyl venlafaxine

A pharmaceutical composition comprising a pharmaceutically effective amount of a compound of Formula I

• 25
• wherein:
• the configuration at the steriogenic center (*) may be R, S, or RS;
• R1 is selected from C1-C6 alkyl, C1-C6 alkoxy, C3-C6 cycloalkyl, or the moiety:
• 26
• R2 is selected from H, or C1-C6 alkyl;
• or,
• R1 and R2 may be concatenated such that
• 27
• form a moiety having formula (b):
• 28
• R3 is selected from H or C1-C6 alkyl;
• and
• R4 and R5 are independently selected from H, C1-C6 alkyl, C3-C6 cycloalkyl, C1-C6 alkoxy, C1-C6 thioalkoxy, —CN, —OH, —CF3, —OCF3, halogen, —NH2, —NO2, or mono or dialkylamino wherein each alkyl group has 1 to 6 carbon atoms, or pharmaceutically acceptable salts or hydrates thereof;
• and a pharmaceutically acceptable carrier or excipient.

A method of treating disorders of the central nervous system in a mammal, the method comprising providing to a mammal in need thereof a pharmaceutically effective amount of a compound of Formula I

• 29
• wherein:
• the configuration at the steriogenic center (*) may be R, S, or RS;
• R1 is selected from C1-C6 alkyl, C1-C6 alkoxy, C3-C6 cycloalkyl, or the moiety:
• 30
• R2 is selected from H, or C1-C6 alkyl;
• or,
• R1 and R2 may be concatenated such that
• 31
• form a moiety having formula (b):
• 32
• R3 is selected from H or C1-C6 alkyl;
• and
• R4 and R5 are independently selected from H, C1-C6 alkyl, C3-C6 cycloalkyl, C1-C6 alkoxy, C1-C6 thioalkoxy, —CN, —OH, —CF3, —OCF3, halogen, —NH2, —NO2, or mono or dialkylamino wherein each alkyl group has 1 to 6 carbon atoms, or a pharmaceutically acceptable salt or hydrate thereof.

A method of enhancing cognition in a mammal, the method comprising providing to a mammal in need thereof a pharmaceutically effective amount of a compound of Formula I

• 33
• wherein:
• the configuration at the steriogenic center (*) may be R, S, or RS;
• R1 is selected from C1-C6 alkyl, C1-C6 alkoxy, C3-C6 cycloalkyl, or the moiety:
• 34
• R2 is selected from H, or C1-C6 alkyl;
• or,
• R1 and R2 may be concatenated such that
• 35
• form a moiety having formula (b):
• 36
• R3 is selected from H or C1-C6 alkyl;
• and
• R4 and R5 are independently selected from H, C1-C6 alkyl, C3-C6 cycloalkyl, C1-C6 alkoxy, C1-C6 thioalkoxy, —CN, —OH, —CF3, —OCF3, halogen, —NH2, —NO2, or mono or dialkylamino wherein each alkyl group has 1 to 6 carbon atoms, or a pharmaceutically acceptable salt or hydrate thereof.