Patent ID: 8361761

Claim:
A method for forming a free base compound of the structure M′ the method comprising: (I.) providing a BOC-protected compound of structure (3) (II.) treating the BOC-protected compound with mesyl chloride, Hünig's base, a compound of structure J and 1-hydroxybenzotriazole (HOBT) to form a BOC-protected intermediate compound of structure K (III.) dehydrating said intermediate K in the presence of pyridine and trifluoroacetic anhydride to obtain a dehydrated reaction product; (IV.) hydrolyzing the dehydrated reaction product in the presence of strong base to form a compound of structure L (V.) treating the compound of structure L with hydrochloric acid to form the corresponding hydrochloric acid salt of structure L′ (VI.) treating the compound of structure L′ with hydrochloric acid and sodium hydroxide to form the free base compound M′.