Patent ID: 8618311

Claim:
A method of making a compound of formula (I): or a pharmaceutically acceptable salt thereof, as a single stereoisomer or as a mixture thereof; wherein: R 3 , R 4 and R 5 are independently bromine, chlorine, fluorine, carboxy, hydrogen, hydroxy, hydroxymethyl, methanesulfonamido, nitro, cyano, sulfamyl, trifluoromethyl, â€”CHF 2 , â€”SO 2 N(R 8 )R 9 , â€”OCF 3 , C 2 -C 7 alkanoyloxy, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 7 -C 12 aralkoxy, C 2 -C 7 alkoxycarbonyl, C 1 -C 6 thioalkyl, aryl or â€”N(R 6 )R 7 ; and R 6 , R 7 , R 8 , and R 9 are each independently selected from hydrogen, acetyl, methanesulfonyl or C 1 -C 6 alkyl; which method comprises: a) a nucleophilic displacement step comprising treating a compound of formula (16): wherein â€”ORâ€² is an activated leaving group and R 3 , R 4 and R 5 are as defined above, with an azide under suitable nucleophilic displacement conditions and subsequent reduction conditions to form a compound of formula (17): wherein R 3 , R 4 and R 5 are as defined above; b) reacting the compound of formula (17): wherein R 3 , R 4 and R 5 are as defined above, with a compound of formula (2a2): wherein R is H, C 2 -C 5 acyl or an oxygen-protecting group, under suitable condensation conditions to form a compound of formula (6b): wherein R is H, C 2 -C 5 acyl or an oxygen-protecting group and R 3 , R 4 and R 5 are as defined above; and c) reducing the compound of formula (6b) under suitable conditions to form a compound of formula (I), as set forth above; and d) optionally forming the pharmaceutically acceptable salt of the compound of formula (I) under suitable conditions.