(7-Methanesulfonylamino-1,1-dioxo-1,4-dihydro-1λ6-benzo[1,2,4]thiadiazin-3-yl)-acetic acid (prepared as described in Example 1j, 0.1 g, 0.3 mmol) was dissolved in anhydrous N,N-dimethylformamide (4 mL). (1R,2S)-2-(4-Fluoro-benzylamino)-cyclohexanecarboxylic acid methyl ester (0.79 g, 0.3 mmol) was added followed by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.06 g, 0.315 mmol). Then N-methylmorpholine (0.07 mL, 0.63 mmol) was added into the above reaction mixture. The mixture was stirred at 25° C. for 2 h. The solution was poured into 1.0 M aqueous hydrochloric acid solution (50 mL). The aqueous layer was extracted with ethyl acetate (2×50 mL). The organic layer was dried over sodium sulfate, filtered and concentrated in vacuo to afford the crude product, (1R,2S)-2-{(4-fluoro-benzyl)-[2-(7-methanesulfonylamino-1,1-dioxo-1,4-dihydro-1λ6-benzo[1,2,4]thiadiazin-3-yl)-acetyl]-amino}-cyclohexanecarboxylic acid methyl ester (0.3 mmol), as a yellow oil. LC-MS (ESI) calcd for C25H29FN4O7S2 580.15, found 581.3 [M+H+].
