Triethylamine → perfluorophenyl 4-(2-chloro-4-(trifluoromethyl)phenyl)-3,4-dihydro-2H-benzo[b][1,4]oxazine-7-sulfonate

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Reaktionsschritte

INTERMEDIATE F was prepared from 4-(2-chloro-4-(trifluoromethyl)phenyl)-3,4-dihydro-2H-benzo[b][1,4]oxazine-7-sulfonyl chloride (INTERMEDIATE E), which was prepared in an analogous fashion to INTERMEDIATE C, except using 2-chloro-1-fluoro-4-(trifluoromethyl)benzene instead of 2-bromo-1-fluoro-4-(trifluoromethyl)benzene in STEP 1. A 25 mL septa/cap vial under Argon was charged with INTERMEDIATE E (0.400 g, 0.970 mmol), and dissolved in DCM (3.6 mL). 2,3,4,5,6-Pentafluorophenol (PFP) (0.268 g, 1.456 mmol) was added, followed by dropwise addition of triethylamine (0.202 mL, 1.46 mmol). The reaction was stirred for 1 hour at room temperature. The resulting material was concentrated, dissolved in minimal DCM and purified via column chromatography (silica gel 40 g, gradient elution 0 to 40% EtOAc:Heptane; product eluted at 30%) to afford perfluorophenyl 4-(2-chloro-4-(trifluoromethyl)phenyl)-3,4-dihydro-2H-benzo[b][1,4]oxazine-7-sulfonate (0.543 g, 0.970 mmol) as a clear colorless oil. m/z (ESI) 391.8 (M-PFP)−.

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