Ethanol → Rac-n-{3-[6-cyclobutyl-1-(4-fluoro-benzyl)-4-hydroxy-2-oxo-1,2,5,6-tetrahydro-pyridin-3-yl]-1,1-dioxo-1,4-dihydro-1lambda6-thieno[2,3-e][1,2,4]thiadiazin-7-ylmethyl}-methanesulfonamide

Participants

Reaction Conditions

Reaction Steps

[7-(Methanesulfonylamino-methyl)-1,1-dioxo-1,4-dihydro-1λ6-thieno[2,3-e][1,2,4]thiadiazin-3-yl]-acetic acid (prepared as described in Example 2c; 0.119 g, 0.337 mmol), O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (0.140 g, 0.368 mmol) and 4-methylmorpholine (0.074 mL, 0.673 mmol) were added sequentially to a solution of rac-3-cyclobutyl-3-(4-fluoro-benzylamino)-propionic acid methyl ester (0.089 g, 0.335 mmol) in N,N-dimethylformamide (5 mL) at 25° C. The reaction mixture was stirred at 25° C. for 22 h, and then was concentrated in vacuo. The residue was partitioned between 1.0 M aqueous hydrochloric acid solution (100 mL) and ethyl acetate (2×100 mL). The organic layers were dried over sodium sulfate and were concentrated in vacuo. The residue was dissolved in ethanol (5 mL) at 25° C. A 21 wt. % solution of sodium ethoxide in ethanol (0.46 mL, 1.42 mmol) was added and the reaction mixture was heated to 60° C. for 4 h. After cooling to 25° C., the reaction mixture was partitioned between 1.0 M aqueous hydrochloric acid solution (100 mL) and ethyl acetate (2×100 mL). The organic layers were dried over sodium sulfate and were concentrated in vacuo. The residue was purified by flash chromatography (Teledyne Isco RediSep column; 60-100% ethyl acetate in hexanes) to afford (after trituration with diethylether) rac-N-{3-[6-cyclobutyl-1-(4-fluoro-benzyl)-4-hydroxy-2-oxo-1,2,5,6-tetrahydro-pyridin-3-yl]-1,1-dioxo-1,4-dihydro-1λ6-thieno[2,3-e][1,2,4]thiadiazin-7-ylmethyl}-methanesulfonamide (0.063 g, 0.111 mmol, 31%) as a tan solid. 1H NMR (400 MHz, DMSO-d6) δ: 1.64-1.94 (4H, m), 2.36 (1H, d, J=17.2 Hz), 2.64-2.71 (1H, m), 2.95 (3H, s), 3.03 (1H, dd, J1=6.5 Hz, J2=17.7 Hz), 3.53-3.57 (1H, m), 4.15 (1H, d, J=14.8 Hz), 4.24 (2H, d, J=6.2 Hz), 5.10 (1H, d, J=15.1 Hz), 7.12-7.16 (2H, m), 7.24 (1H, s), 7.34-7.38 (2H, m), 7.64 (1H, t, J=6.2 Hz). LC-MS (ESI) calculated for C23H25FN4O6S3 568.09. found 569.2 [M+H+].

Provenance & Evidence