Patent ID: 6914158

Claim:
A method for the preparation of a compound or a pharmaceutically acceptable salt thereof, the compound having a structure corresponding to Formula 21: or a salt thereof, wherein: X is selected from the group consisting of —S—, —S(O)—, and —S(O) 2 —; R 2 is selected from the group consisting of C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 5 alkoxy-C 1 alkyl, and C 1 -C 5 alkylthio-C 1 alkyl; R 30 is selected from the group consisting of —H, —OH, —C(O)—R 17 , —C(O)—O—R 18 , and —C(O)—S—R 19 ; R 1 , R 5 , R 6 , and R 7 independently are selected from the group consisting of —H, halogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, and C 1 -C 5 alkoxy-C 1 alkyl; R 9 and R 10 independently are selected from the group consisting of —H, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, and C 1 -C 5 alkoxy-C 1 alkyl; with respect to R 11 and R 12 : R 11 is selected from the group consisting of —H, —OH, —C(O)—O—R 24 , and —C(O)—S—R 25 ; and R 12 is selected from the group consisting of —H, —OH, —C(O)—O—R 26 , and —C(O)—S—R 27 ; or R 11 is —O—, and R 12 is —C(O)—, wherein R 11 and R 12 together with the atoms to which they are attached form a ring; or R 11 is —C(O)—, and R 12 is —O—, wherein R 11 and R 12 together with the atoms to which they are attached form a ring; and R 13 is C 1 alkyl; R 17 , R 18 , R 19 , R 24 , R 25 , R 26 , R 27 and R 27a independently are selected from the group consisting of —H and alkyl, which is optionally substituted by one or more moieties selected from the group consisting of cycloalkyl, heterocyclyl, aryl, and heteroaryl; and when any of R 1 , R 2 , R 4 , R 5 , R 6 , R 7 , R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 , R 24 , R 25 , R 25 R 26 , R 27 and R 27a independently is a moiety selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, alkylthio, cycloalkyl, heterocyclyl, aryl, and heteroaryl, then the moiety is optionally substituted by one or more substituent selected from the group consisting of —OH, alkoxy, and halogen; wherein the method comprises treating a diamine compound having a structure corresponding to Formula 22: or a pharmaceutically acceptable salt thereof, with an alkyl acetimidate having a structure corresponding to Formula 23: or a salt thereof, wherein R 31 is C 1 -C 6 alkyl, to produce the compound corresponding to Formula 21.