Methods for synthesis of acyloxyalkyl derivatives of GABA analogs

1. A compound of Formula (II)

wherein:

X is F, Cl, Br or I;

n is 0 or 1;

R 2 and R 3 are independently hydrogen, alkyl, substituted alkyl, alkoxycarbonyl, substituted alkoxycarbonyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, carbamoyl, substituted carbamoyl, cycloalkyl, substituted cycloalkyl, heteroalkyl, substituted heteroalkyl, heteroaryl, substituted heteroaryl, heteroarylalkyl or substituted heteroarylalkyl, or optionally, R 2 and R 3 together with the atom to which they are bonded form a cycloalkyl, substituted cycloalkyl, cycloheteroalkyl or substituted cycloheteroalkyl ring;

R 4 is hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substituted cycloheteroalkyl, heteroalkyl, substituted heteroalkyl, heteroaryl, substituted heteroaryl, heteroarylalkyl or substituted heteroarylalkyl;

R 5 is hydrogen, alkyl, substituted alkyl, alkoxy, substituted alkoxy, acyl, substituted acyl, alkoxycarbonyl, substituted alkoxycarbonyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, carbamoyl, substituted carbamoyl, cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substituted cycloheteroalkyl, heteroalkyl, substituted heteroalkyl, heteroaryl, substituted heteroaryl, heteroarylalkyl or substituted heteroarylalkyl, or optionally, R 4 and R 5 together with the atoms to which they are attached form a cycloheteroalkyl or substituted cycloheteroalkyl ring;

R 6 and R 9 are independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substituted cycloheteroalkyl, heteroaryl, substituted heteroaryl, heteroarylalkyl and substituted heteroarylalkyl;

R 7 and R 8 are independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, acyl, substituted acyl, arylalkyl, substituted arylalkyl, cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substituted cycloheteroalkyl, heteroarylalkyl and substituted heteroarylalkyl, or optionally, R 7 and R 8 together with the carbon atom to which they are attached form a cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substituted cycloheteroalkyl or bridged cycloalkyl ring; and

R 10 is hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, aryldialkylsilyl, cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substituted cycloheteroalkyl, heteroalkyl, substituted heteroalkyl, heteroaryl, substituted heteroaryl, heteroarylalkyl, substituted heteroarylalkyl or trialkylsilyl.

2. The compound of claim 1 derived from a GABA analog of Formula (IV):

wherein the GABA analog of Formula (IV) is selected from the group consisting of:

1-Aminomethyl-1-cyclohexane acetic acid (i.e. gabapentin);

1-Aminomethyl-1-(3-methylcyclohexane) acetic acid;

1-Aminomethyl-1-(4-methylcyclohexane) acetic acid;

1-Aminomethyl-1-(4-isopropylcyclohexane) acetic acid;

1-Aminomethyl-1-(4-tert-butylcyclohexane) acetic acid;

1-Aminomethyl-1-(3,3-dimethylcyclohexane) acetic acid;

1-Aminomethyl-1-(3,3,5,5-tetramethylcyclohexane) acetic acid;

1-Aminomethyl-1-cyclopentane acetic acid;

1-Aminomethyl-1-(3-methylcyclopentane) acetic acid;

1-Aminomethyl-1-(3,4-dimethylcyclopentane) acetic acid;

7-Aminomethyl-bicyclo[2.2.1]hept-7-yl acetic acid;

9-Aminomethyl-bicyclo[3.3.1]non-9-yl acetic acid;

4-Aminomethyl-4-(tetrahydropyran-4-yl) acetic acid;

3-Aminomethyl-3-(tetrahydropyran-3-yl) acetic acid;

4-Aminomethyl-4-(tetrahydrothiopyran-4-yl) acetic acid;

3-Aminomethyl-3-(tetrahydrothiopyran-3-yl) acetic acid;

(S)-3-Aminomethyl-5-methyl-hexanoic acid (i.e., pregabalin);

3-Aminomethyl-5-methyl-heptanoic acid;

3-Aminomethyl-5-methyl-octanoic acid;

3-Aminomethyl-5-methyl-nonanoic acid;

3-Aminomethyl-5-methyl-decanoic acid;

3-Aminomethyl-5-cyclopropyl-hexanoic acid;

3-Aminomethyl-5-cyclobutyl-hexanoic acid;

3-Aminomethyl-5-cyclopentyl-hexanoic acid;

3-Aminomethyl-5-cyclohexyl-hexanoic acid;

3-Aminomethyl-5-phenyl-hexanoic acid;

3-Aminomethyl-5-phenyl-pentanoic acid;

3-Aminomethyl-4-cyclobutyl-butyric acid;

3-Aminomethyl-4-cyclopentyl-butyric acid;

3-Aminomethyl-4-cyclohexyl-butyric acid;

3-Aminomethyl-4-phenoxy-butyric acid;

3-Aminomethyl-5-phenoxy-hexanoic acid; and

3-Aminomethyl-5-benzylsulfanyl-pentanoic acid.

3. The compound of claim 1 , wherein the compound of Formula (II) is a compound of Formulae (VII) or (VIII):

and n is 0.

4. The compound of claim 3 , wherein X is chloro, bromo or iodo, R 10 is hydrogen, allyl, benzyl or trimethylsilyl, R 2 is hydrogen, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclohexyl or phenyl and R 3 is hydrogen.

5. The compound of claim 3 , wherein X is chloro, bromo or iodo, R 10 is hydrogen, allyl, benzyl or trimethylsilyl, R 2 is methyl and R 3 is methyl.

6. The compound of claim 5 , wherein X is chloro, bromo or iodo, R 10 is hydrogen, allyl, benzyl or trimethylsilyl, R 2 is methoxycarbonyl, ethoxycarbonyl, isopropoxycarbonyl or cyclohexyloxycarbonyl and R 3 is methyl.

7. The compound of claim 3 , wherein X is chloro, bromo or iodo, R 1 is hydrogen, allyl, benzyl or trimethylsilyl, and R 2 and R 3 together with the atom to which they are attached form a cyclohexyl ring.

8. The compound of claim 3 , wherein X is chloro, R 10 is hydrogen, allyl, benzyl or trimethylsilyl, R 2 is hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl and R 3 is hydrogen.

9. The compound of claim 3 , wherein X is chloro, R 10 is hydrogen, allyl, benzyl or trimethylsilyl, R 2 is methyl, n-propyl or isopropyl, and R 3 is hydrogen.

10. The compound of claim 3 , wherein X is chloro, R 10 is hydrogen, R 2 is methyl, and R 3 is hydrogen.

11. The compound of claim 3 , wherein X is chloro, R 10 is allyl, R 2 is methyl, and R 3 is hydrogen.

12. The compound of claim 3 , wherein X is chloro, R 10 is benzyl, R 2 is methyl, and R 3 is hydrogen.

13. The compound of claim 3 , wherein X is chloro, R 10 is trimethylsilyl, R 2 is methyl, and R 3 is hydrogen.