Patent ID: 8431599

Claim:
A method of treating chronic pain a mammal in need of such treatment, comprising administering to said mammal at least one compound of the formula or a pharmaceutically acceptable salt thereof, wherein: R 1 is H or alkyl of 1 to 6 carbons; R 2 is selected from the group consisting of H, and alkyl of 1 to 6 carbons; or the R 1 and R 2 groups together with the nitrogen atom to which they are shown attached form a saturated or unsaturated 4, 5, 6 or 7 membered ring that optionally additionally includes one or two heteroatoms independently selected from the group consisting of N, O and S, said 4, 5, 6 or 7 membered ring optionally being substituted with one or two COOH, CH 2 OH, OH, B(OH) 2 , halogen groups, cyano groups or with one or two alkyl groups having 1 to 6 carbons; R 3 is H, CO—R 7 or CO—O—R 7 where R 7 is H, alkyl of 1 to 1 to 20 carbons, cycloalkyl of 3 to 6 carbons, aryl or heteroaryl, aryl-alkyl, aryl(hydroxy)alkyl, heteroaryl-alkyl or heteroalkyl(hydroxy)alkyl where the alkyl moiety has 1 to 4 carbons, said aryl or heteroaryl groups being optionally substituted with 1 to 3 groups independently selected from the group consisting of halogen, alkyl of 1 to 6 carbons, alkoxy of 1 to 6 carbons and thioxy of 1 to 3 carbons; R 4 is H, alkyl of 1 to 6 carbons, or CO—R 8 where R 8 is alkyl of 1 to 6 carbons; R 5 and R 6 are independently selected from the group consisting of H, halogen, alkyl of 1 to 6 carbons, alkoxy of 1 to 6 carbons and thioxy of 1 to 3 carbons; or R 5 and R 6 together with the atoms to which they are attached jointly form a carbocyclic or a heterocyclic ring, the carbocyclic ring having 5 or 6 atoms in the ring, the heterocyclic ring having 5 or 6 atoms in the ring and 1 to 3 heteroatoms independently selected from N, O and S; said carbocyclic or heterocyclic ring jointly formed by R 5 and R 6 being optionally substituted with 1 to 6 R 9 groups where R 9 is independently selected from halogen, alkyl of 1 to 6 carbons, alkoxy of 1 to 6 carbons, and the wavy lines represent bonds of the alpha or beta configuration; and wherein said chronic pain is associated with peripheral neuropathy.