Patent ID: 8309727

Claim:
A method for converting a compound according to Formula II or a pharmaceutically acceptable salt thereof into a compound according to Formula III or a pharmaceutically acceptable salt thereof, the method comprising: reducing the compound according to Formula II or a pharmaceutically acceptable salt thereof with a hydrogen transfer reagent in the presence of a metal catalyst to form the compound according to Formula III or a pharmaceutically acceptable salt thereof wherein R 1 and R 3 are independently selected from H; benzyl; 1-8 carbon alkane sulfonyl; p-tosyl; an alkyl group of 1-20 carbons; a substituted alkyl group, wherein the alkyl group is substituted with phenyl, substituted phenyl, 1-8 carbon alkoxyl or phenoxyl groups; and RCO, wherein R is an alkyl group of 1-20 carbons or an aryl group, and wherein: (a) the hydrogen transfer reagent is selected from the group consisting of HCO 2 H/HCO 2 NH 4 , HCO 2 H/HCO 2 Na, HCO 2 H/NEt 3 , HCHO and HCHO/NR 3 , wherein each R group is independently selected from H, alkyl, aryl and mixtures thereof; or (b) the reaction temperature is maintained at about 60° C. to about 110° C.