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

Participants

Reaction Conditions

Reaction Steps

A 5-mL glass microwave reaction vessel was charged with 4-(2-chloro-4-(trifluoromethyl)phenyl)-N-(pyrimidin-4-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine-7-sulfonamide (0.075 g, 0.159 mmol), (N-tert-butoxycarbonyl)-1,2,3,6-tetrahydropyridine-4-boronic acid pinacol ester (0.123 mL, 0.398 mmol), 1,1-bis[(di-t-butyl-p-methylaminophenyl]palladium(II) chloride (0.017 g, 0.024 mmol), potassium phosphate (0.053 mL, 0.637 mmol) and sealed with a septa cap. The reaction head space was flushed with nitrogen and dioxane (0.6 mL) and water (0.2 mL) were added. The mixture was sparged with nitrogen for 5 min. The reaction mixture was stirred and heated in a microwave reactor at 115° C. for 3 h. The reaction mixture was diluted with EtOAc and the organic layer was decanted from the aqueous layer at the bottom of the vial by pipet. 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 70% EtOAc in Heptanes to provide tert-butyl 4-(2-(7-(N-(pyrimidin-4-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 taken up in 0.5 mL DCM and 0.5 mL of trifluoroacetic acid was added and the solution was maintained at rt for 10 min. The solution was concentrated to dryness and then triturated with ether and IPA to give N-(pyrimidin-4-yl)-4-(2-(1,2,3,6-tetrahydropyridin-4-yl)-4-(trifluoromethyl)phenyl)-3,4-dihydro-2H-benzo[b][1,4]oxazine-7-sulfonamide 2,2,2-trifluoroacetate (0.005 g, 7.92 μmol) as a white solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 3.13-3.25 (m, 3 H) 3.57-3.64 (m, 3 H) 3.65-3.72 (m, 3 H) 4.24-4.40 (m, 2 H) 5.82-5.94 (m, 1 H) 6.42-6.55 (m, 1 H) 7.01-7.14 (m, 1 H) 7.24-7.38 (m, 2 H) 7.53-7.67 (m, 2 H) 7.72-7.82 (m, 1 H) 8.32-8.47 (m, 1 H) 8.63-8.72 (m, 1 H) 8.73-8.86 (m, 2 H).

Provenance & Evidence