Prodrugs of GABA analogs, compositions and uses thereof

1. A compound of Formula (I):

or a pharmaceutically acceptable salt thereof, wherein:

n is 1;

X is O or NR 16 ;

Y is O or S;

R 1 is selected from the group consisting of hydrogen, R 24 C(O)—, R 25 OC(O)—, R 24 C(S)—, R 25 OC(S)—, R 25 SC(O)—, R 25 SC(S)—, (R 9 O)(R 10 O)P(O)—, R 25 S—,

m is 0 or 1;

W is O or NR 17 ;

R 2 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkoxy, substituted alkoxy, acyl, substituted acyl, acylamino, substituted acylamino, alkylamino, substituted alkylamino, alkylsulfinyl, substituted alkylsulfinyl, alkylsulfonyl, substituted alkylsulfonyl, alkylthio, substituted alkylthio, alkoxycarbonyl, substituted alkoxycarbonyl, C 6 -C 20 aryl, substituted C 6 -C 20 aryl, arylalkyl, substituted arylalkyl, aryloxy, substituted aryloxy, carbamoyl, substituted carbamoyl, cycloalkyl, substituted cycloalkyl, C 3 -C 10 cycloheteroalkyl, substituted C 3 -C 10 cycloheteroalkyl, dialkylamino, substituted dialkylamino, halo, heteroalkyl, substituted heteroalkyl, C 5-20 heteroaryl, substituted C 5-20 heteroaryl, heteroarylalkyl, substituted heteroarylalkyl, heteroalkyloxy, substituted heteroalkyloxy, heteroaryloxy and substituted heteroaryloxy or optionally, R 2 and R 16 together with the atoms to which they are bonded form a C 3 -C 10 cycloheteroalkyl or substituted C 3 -C 10 cycloheteroalkyl ring;

R 3 and R 6 are independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, C 6 -C 20 aryl, substituted C 6 -C 20 aryl, arylalkyl, substituted arylalkyl, cycloalkyl, substituted cycloalkyl, C 3 -C 10 cycloheteroalkyl, substituted C 3 -C 10 cycloheteroalkyl, C 5-20 heteroaryl, substituted C 5-20 heteroaryl, heteroarylalkyl and substituted heteroarylalkyl;

R 4 and R 5 are independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, acyl, substituted acyl, arylalkyl, substituted arylalkyl, cycloalkyl, substituted cycloalkyl, C 3 -C 10 cycloheteroalkyl, substituted C 3 -C 10 cycloheteroalkyl, heteroarylalkyl and substituted heteroarylalkyl or optionally, R 4 and R 5 together with the carbon atom to which they are bonded form a cycloalkyl, substituted cycloalkyl, C 3 -C 10 cycloheteroalkyl, substituted C 3 -C 10 cycloheteroalkyl or bridged cycloalkyl ring;

R 8 and R 12 are independently selected from the group consisting of hydrogen, acyl, substituted acyl, alkoxycarbonyl, substituted alkoxycarbonyl, alkyl, substituted alkyl, C 6 -C 20 aryl, substituted C 6 -C 20 aryl, arylalkyl, substituted arylalkyl, cycloalkyl, substituted cycloalkyl, C 3 -C 10 cycloheteroalkyl, substituted C 3 -C 10 cycloheteroalkyl, heteroalkyl, substituted heteroalkyl, C 5-20 heteroaryl, substituted C 5-20 heteroaryl, heteroarylalkyl and substituted heteroarylalkyl, or optionally R 8 and R 12 together with the carbon atoms to which they are bonded form a cycloalkyl, substituted cycloalkyl, C 3 -C 10 cycloheteroalkyl or substituted C 3 -C 10 cycloheteroalkyl ring;

R 11 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, acyl, substituted acyl, C 6 -C 20 aryl, substituted C 6 -C 20 aryl, arylalkyl, substituted arylalkyl, carbamoyl, substituted carbamoyl, cyano, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, C 5-20 heteroaryl, substituted C 5-20 heteroaryl, heteroarylalkyl, substituted heteroarylalkyl, alkoxycarbonyl, substituted alkoxycarbonyl, cycloheteroalkyloxycarbonyl, substituted cycloheteroalkyloxycarbonyl, aryloxycarbonyl, substituted aryloxycarbonyl, heteroaryloxycarbonyl, substituted heteroaryloxycarbonyl and nitro;

R 7 , R 9 , R 10 , R 15 , R 16 and R 17 are independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, C 6 -C 20 aryl, substituted C 6 -C 20 aryl, arylalkyl, substituted arylalkyl, cycloalkyl, substituted cycloalkyl, C 3 -C 10 cycloheteroalkyl, substituted C 3 -C 10 cycloheteroalkyl, heteroalkyl, substituted heteroalkyl, C 5-20 heteroaryl, substituted C 5-20 heteroaryl, heteroarylalkyl and substituted heteroarylalkyl;

R 13 and R 14 are independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkoxycarbonyl, substituted alkoxycarbonyl, C 6 -C 20 aryl, substituted C 6 -C 20 aryl, arylalkyl, substituted arylalkyl, carbamoyl, substituted carbamoyl, cycloalkyl, substituted cycloalkyl, cycloalkoxycarbonyl, substituted cycloalkoxycarbonyl, C 5-20 heteroaryl, substituted C 5-20 heteroaryl, heteroarylalkyl and substituted heteroarylalkyl or optionally, R 13 and R 14 together with the carbon atom to which they are bonded form a cycloalkyl, substituted cycloalkyl, C 3 -C 10 cycloheteroalkyl or substituted C 3 -C 10 cycloheteroalkyl ring;

R 24 is selected from the group consisting of hydrogen, acyl, substituted acyl, alkyl, substituted alkyl, C 6 -C 20 aryl, substituted C 6 -C 20 aryl, arylalkyl, substituted arylalkyl, cycloalkyl, substituted cycloalkyl, C 3 -C 10 cycloheteroalkyl, substituted C 3 -C 10 cycloheteroalkyl, heteroalkyl, substituted heteroalkyl, C 5-20 heteroaryl, substituted C 5-20 heteroaryl, heteroarylalkyl and substituted heteroarylalkyl; and

R 25 is selected from the group consisting of acyl, substituted acyl, alkyl, substituted alkyl, C 6 -C 20 aryl, substituted C 6 -C 20 aryl, arylalkyl, substituted arylalkyl, cycloalkyl, substituted cycloalkyl, C 3 -C 10 cycloheteroalkyl, substituted C 3 -C 10 cycloheteroalkyl, heteroalkyl, substituted heteroalkyl, C 5-20 heteroaryl, substituted C 5-20 heteroaryl, heteroarylalkyl and substituted heteroarylalkyl; and

with the provisos that:

when R 3 and R 6 are both hydrogen, then R 4 and R 5 are neither both hydrogen nor both C 1 to C 10 alkyl;

when X is NR 16 , then R 1 is not hydrogen;

when R 1 is R 25 OC(O)—, then R 25 is not R 26 C(O)CR 13 R 14 , wherein R 26 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, C 6 -C 20 aryl, substituted C 6 -C 20 aryl, arylalkyl, substituted arylalkyl, cycloalkyl, substituted cycloalkyl, C 3 -C 10 cycloheteroalkyl, substituted C 3 -C 10 cycloheteroalkyl, heteroalkyl, substituted heteroalkyl, C 5-20 heteroaryl, substituted C 5-20 heteroaryl, heteroarylalkyl and substituted heteroarylalkyl;

when X is NH, R 3 , R 5 and R 6 are each hydrogen, and R 4 is cyclohexyl, then R 2 is not arylalkyl,

wherein each substituent is independently selected from —Z, —R 29 , —O − , ═O, —OR 29 , —SR29, —S − , ═S, —NR 29 R 30 , ═NR 29 , —CZ 3 , —CF 3 , —CN, —OCN, —SCN, —NO, —NO 2 , ═N 2 , —N 3 , —S(O) 2 O − , —S(O) 2 OH, —S(O) 2 R 29 , —OS(O 2 )O − , —OS(O) 2 R 29 , —P(O)(O − ) 2 , —P(O)(OR 29 )(O − ), —OP(O)(OR 29 )(OR 30 ), —C(O)R 29 , —C(S)R 29 , —C(O)OR 29 , —C(O)NR 29 R 30 , —C(O)O − , —C(S)OR 29 , —NR 31 C(O)NR 29 R 30 , —NR 31 C(S)NR 29 R 30 , —NR 31 C(NR 29 )R 29 R 30 , —C(NR 29 )NR 29 R 30 , where each Z is independently a halogen; each R 29 and R 30 are independently hydrogen, alkyl, substituted alkyl, C 6 -C 20 aryl, substituted C 6 -C 20 aryl, arylalkyl, substituted arylalkyl, cycloalkyl, substituted cycloalkyl, C 3 -C 10 cycloheteroalkyl, substituted C 3 -C 10 cycloheteroalkyl, heteroalkyl, substituted heteroalkyl, C 5-20 heteroaryl, substituted C 5-20 heteroaryl, heteroarylalkyl, substituted heteroarylalkyl, —NR 31 R 32 , —C(O)R 31 or —S(O) 2 R 31 or optionally R 29 and R 30 together with the atom to which they are both bonded form a C 3 -C 10 cycloheteroalkyl ring or substituted C 3 -C 10 cycloheteroalkyl ring; and R 31 and R 32 are independently hydrogen, alkyl, substituted alkyl, C 6 -C 20 aryl, substituted C 6 -C 20 aryl, arylalkyl, substituted arylalkyl, cycloalkyl, substituted cycloalkyl, C 3 -C 10 cycloheteroalkyl, substituted C 3 -C 10 cycloheteroalkyl, heteroalkyl, substituted heteroalkyl, C 5-20 heteroaryl, substituted C 5-20 heteroaryl, heteroarylalkyl and substituted heteroarylalkyl,

wherein each C 5-20 heteroaryl is derived from a member of the group selected from thiophene, pyrrole, benzothiophene, benzofuran, indole, pyridine, quinoline, imidazole, oxazole and pyrazine; and

wherein each C 3 -C 10 cycloheteroalkyl is independently derived from a member of the group consisting of epoxides, imidazolidine, morpholine, piperazine, piperidine, pyrazolidine, pyrrolidine, and quinuclidine.

2. The compound or pharmaceutically acceptable salt according to claim 1 , wherein R 4 is alkyl and R 5 is hydrogen, or R 4 and R 5 together with the carbon atom to which they are bonded are cycloalkyl.

3. The compound or pharmaceutically acceptable salt according to claim 1 , wherein R 4 is isobutyl and R 5 is hydrogen, or R 4 and R 5 together with the carbon atom to which they are bonded form a cyclohexyl ring.

4. The compound or pharmaceutically acceptable salt according to claim 1 , wherein

Y is O;

R 1 is the formula

W is O; and

R 25 is selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, sec-pentyl, neopentyl, 1,1-dimethoxyethyl, 1,1-diethoxyethyl, 1-(1,3-dioxolan-2-yl)-ethyl, 1-(1,3-dioxan-2-yl)-ethyl, 1,1-dimethoxypropyl, 1,1-diethoxypropyl, 1-(1,3-dioxolan-2-yl)-propyl, 1-(1,3-dioxan-2-yl)-propyl, 1,1-dimethoxybutyl, 1,1-diethoxybutyl, 1-(1,3-dioxolan-2-yl)-butyl, 1-(1,3-dioxan-2-yl)-butyl, 1,1-dimethoxybenzyl, 1,1-diethoxybenzyl, 1-(1,3-dioxolan-2-yl)-benzyl, 1-(1,3-dioxan-2-yl)-benzyl, 1,1-dimethoxy-2-phenethyl, 1,1-diethoxy-2-phenethyl, 1-(1,3-dioxolan-2-yl)-2-phenethyl, and 1-(1,3-dioxan-2-yl)-2-phenethyl.

5. The compound or pharmaceutically acceptable salt according to claim 1 , 3 or 4 , wherein X is NR 16 and R 16 is hydrogen.

6. The compound or pharmaceutically acceptable salt according to claim 1 , 3 , or 4 , wherein R 2 is substituted arylalkyl.