Ethanol → Rac-n-{3-[5-tert-butyl-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; 0.164 g, 0.464 mmol), O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (0.195 g, 0.513 mmol) and 4-methylmorpholine (0.102 mL, 0.928 mmol) were added sequentially to a solution of rac-2-[(4-fluoro-benzylamino)-methyl]-3-methyl-butyric acid ethyl ester (0.131 g, 0.466 mmol) in N,N-dimethylformamide (5 mL) at 25° C. The reaction mixture was stirred at 25° C. for 16 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 (10 mL) at 25° C. A 21 wt. % solution of sodium ethoxide in ethanol (1.81 mL, 5.58 mmol) was added and the reaction mixture was heated to 70° C. for 84 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-[5-tert-butyl-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 (0.1111 g, 0.195 mmol, 42%) as a beige solid. 1H NMR (400 MHz, DMSO-d6) δ: 0.92 (9H, s), 2.36 (1H, bs), 2.96 (3H, s), 3.44 (1H, d, J=14.3 Hz), 3.59 (1H, dd, J=5.5 Hz, J2=14.2 Hz), 4.25 (2H, d, J=6.1 Hz), 4.44 (1H, d, J=14.6 Hz), 4.79 (1H, d, J=13.9 Hz), 7.14-7.18 (2H, m), 7.27 (1H, s), 7.39-7.42 (2H, m), 7.65 (1H, t, J=6.2 Hz). LC-MS (ESI) calculated for C23H27FN4O6S3 570.11. found 571.2 [M+H+].

Provenance & Evidence