Reaction Steps
Methyl (1S,2S,3R,4R)-3-[(4-fluorobenzyl)amino]bicyclo[2.2.1]heptane-2-carboxylate (0.087 g, 0.3 mmol) was dissolved in anhydrous N,N-dimethylformamide (2.8 mL). (7-Methanesulfonylamino-1,1-dioxo-1,4-dihydro-1λ6-benzo[1,2,4]thiadiazin-3-yl)-acetic acid (prepared as described in Example 1g, 0.1 g, 0.3 mmol) was added followed by N-methylmorpholine (0.07 mL, 0.63 mmol). The mixture was stirred until everything dissolved, approximately 5 min. 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.061 g, 0.315 mmol) was added and the mixture was stirred at 25° C. for 4 h. Triethylamine (0.126 mL, 0.9 mmol) was added and the mixture was stirred at 50° C. for 16 h. Upon cooling to 25° C., the solution was diluted with ethyl acetate (25 mL) and washed with 1.0M aqueous hydrochloric acid solution (2×25 mL), saturated aqueous brine solution (10 mL), dried over magnesium sulfate, filtered, and concentrated in vacuo to afford a golden oil. The oil was dissolved in methanol (4 mL) and the product was precipitated by the addition of 1.0M aqueous hydrochloric acid solution (4 mL) while stirring. The solid was collected by vacuum filtration and further dried in vacuo to afford the desired product, N-{3-[(1R,2R,7S,8S)-3-(4-fluoro-benzyl)-6-hydroxy-4-oxo-3-aza-tricyclo[6.2.1.02,7]undec-5-en-5-yl]-1,1-dioxo-1,4-dihydro-1λ6-benzo[1,2,4]thiadiazin-7-yl}-methanesulfonamide (0.0781 g, 0.139 mmol, 46%), as a white powder. 1H NMR (400 MHz, DMSO-d6) δ: 1.23-1.48 (6H, m), 2.67-2.68 (2H, m), 3.06 (3H, s), 3.24 (1H, d, J=15.0 Hz), 3.72 (1H, d, J=11.9 Hz), 4.07 (1H, d, J=15.6 Hz), 5.12 (1H, d, J=15.7 Hz), 7.14 (2H, t, J=8.4 Hz), 7.39 (2H, dd, J1=8.2 Hz, J2=5.8 Hz), 7.51 (1H, dd, J1=8.4 Hz, J2=2.3 Hz), 7.57-7.60 (2H, m), 10.18 (1H, s). LC-MS (ESI) calcd for C25H25FN4O6S2 560.12, found 561.3 [M+H+]. ee=99% [HPLC-analysis: Chiralpak AS-RH 4.6×250 mm, 5 micron at r.t., Solvent A-Solvent B (see table for gradient), 0.8 mL/min, 310 nm, t1=7.58 min, t2=10.08 min (major)].
