(S)-2-({(3R,8S)-7-(2-acetylamino-4-methyl-thiazole-5-sulfonyl)-3-[4-(3,4-dichloro-benzyloxy)-phenyl]-2,3,6,7,8,9-hexahydro-[1,4]dioxino[2,3-g]isoquinoline-8-carbonyl}-amino)-3-(4'-cyano-biphenyl-4-yl)-propionic acid methyl ester   、                                                                                      
碘甲烷                                                                                                                                                                                                                                                                                                          以to obtain (S)-2-({(3R,8S)-7-[2-(acetyl-methyl-amino)-4-methyl-thiazole-5-sulfonyl]-3-[4-(3,4-dichloro-benzyloxy)-phenyl]-2,3,6,7,8,9-hexahydro-[1,4]dioxino[2,3-g]isoquinoline-8-carbonyl}-amino)-3-(4′-cyano-biphenyl-4-yl)-propionic acid methyl ester的产率得到(S)-2-({(3R,8S)-7-[2-(acetyl-methyl-amino)-4-methyl-thiazole-5-sulfonyl]-3-[4-(3,4-dichloro-benzyloxy)-phenyl]-2,3,6,7,8,9-hexahydro-[1,4]dioxino[2,3-g]isoquinoline-8-carbonyl}-amino)-3-(4'-cyano-biphenyl-4-yl)-propionic acid methyl ester