Patent ID: 7838686

Claim:
A method of making a compound of Formula 1, or a pharmaceutically acceptable complex, salt, solvate or hydrate thereof, in which R 1 and R 2 are different and are each independently selected from hydrogen atom, C 1-12 alkyl, C 3-12 cycloalkyl, and substituted C 3-12 cycloalkyl, the method comprising: (a) reducing a cyano moiety of a compound of Formula 3, or a salt thereof, to yield the compound of Formula 2 or a salt thereof; wherein R 1 and R 2 are as defined above and R 3 in Formula 3 is C 1-12 alkyl, C 3-12 cycloalkyl, or aryl-C 1-6 alkyl; (b) reacting a compound of Formula 2, or a salt thereof, with an acid and water to yield the compound of Formula 1 or a salt thereof; and (c) optionally converting the compound of Formula 1 or a salt thereof into a pharmaceutically acceptable complex, salt, solvate or hydrate, wherein R 1 and R 2 in Formula 2 are as defined in Formula 1.