| 主权项 |
1. A process for preparing a compound of structure (VI): or a stereoisomer or pharmaceutically acceptable salt thereof, wherein:
R1a, R1b and R1c are the same or different and independently hydrogen, halogen, C1-4alkyl, hydroxy or alkoxy;R2a and R2b are the same or different and independently hydrogen, halogen, trifluoromethyl, cyano or —SO2CH3;R3 is hydrogen or methyl; andR4 is H, —C1-6alkanediyl-COOH, or —C(═O)O-(t-butyl);comprising as an intermediate synthesis step:reacting a compound of structure (VII): wherein R2a, R2b and R3 are as defined above;with a compound of structure (VIII): wherein R is H or C1-4-alkyl, R′ is H or C1-4-alkyl or R and R′ taken together form C1-6alkanediyl; andR1a, R1b, and R1c are as defined above; and reacting methanesulfonic acid-(S)-3-tert-butoxycarbonyl-amino-3-phenyl-propyl ester with the compound formed by reacting compound (VII) with compound (VIII), which compound has the structure: in the presence of a base. |
