Potassium Phosphate, Tribasic → tert-butyl 4-(2-(7-(N-(4-methoxybenzyl)-N-(thiazol-2-yl)sulfamoyl)-2H-benzo[b][1,4]oxazin-4(3 H)-yl)-5-(trifluoromethyl)phenyl)-5,6-dihydropyridine-1(2 H)-carboxylate

関与物質

反応条件

反応手順

A 5-mL glass microwave reaction vessel was charged with 4-(2-chloro-4-(trifluoromethyl)phenyl)-N-(4-methoxybenzyl)-N-(thiazol-2-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine-7-sulfonamide (INTERMEDIATE X, 0.150 g, 0.252 mmol), (n-tert-butoxycarbonyl)-1,2,3,6-tetrahydropyridine-4-boronic acid pinacol ester (0.195 mL, 0.629 mmol), 1,1-bis[(di-t-butyl-p-methylaminophenyl]palladium(II) chloride (0.027 g, 0.038 mmol), and potassium phosphate (0.083 mL, 1.007 mmol). The vessel was sealed and flushed with N2. Dioxane (1 mL) and water (0.32 mL) were added via syringe and the mixture was sparged with N2 for 5 min. The reaction mixture was stirred and heated in a microwave reactor at 112° C. for 3 h. After cooling to rt, the reaction was diluted with EtOAc and the organic layer was decanted from aqueous layer at the bottom of the vial. The organic layer was concentrated and absorbed onto a 5 g loading cartridge and passed through a silica gel column (12 g) using a gradient from 0% to 60% EtOAc in Heptanes to provide tert-butyl 4-(2-(7-(N-(4-methoxybenzyl)-N-(thiazol-2-yl)sulfamoyl)-2H-benzo[b][1,4]oxazin-4(3 H)-yl)-5-(trifluoromethyl)phenyl)-5,6-dihydropyridine-1(2 H)-carboxylate. This product was dissolved in DCM (5 mL) and the solution was cooled to 0° C. Trifluoroacetic acid (1 mL) was added dropwise to generate a bright pink solution. The cold bath was removed and the solution was stirred for 30 min. Additional trifluoroacetic acid (1 mL) was added dropwise and the solution was maintained at rt for 5 min. The solution was partitioned between ice/brine and DCM. The layers were separated and the aqueous layer was extracted with DCM (3×). The combined organic layers were dried (Na2SO4) and concentrated. The resulting residue was dissolved in MeOH/DMSO and purified by reverse-phase preparative HPLC using 0.1% TFA in CH3CN/H2O, gradient 10% to 80% over 15 min to provide 4-(2-(1,2,3,6-tetrahydropyridin-4-yl)-4-(trifluoromethyl)phenyl)-N-(thiazol-2-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine-7-sulfonamide 2,2,2-trifluoroacetate (0.075 g, 0.118 mmol) as a white solid. 1H NMR (500 MHz, DMSO-d6) δ ppm 3.20 (br. s., 4 H) 3.52-3.62 (m, 2 H) 3.69 (br. s., 2 H) 4.28 (br. s., 2 H) 5.89 (br. s., 1 H) 6.48 (d, J=8.55 Hz, 1 H) 6.79 (d, J=4.59 Hz, 1 H) 7.08-7.26 (m, 3 H) 7.53-7.66 (m, 2 H) 7.70-7.80 (m, 1 H) 8.67-8.87 (m, 2 H) 12.46-12.62 (m, 1 H).

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