反应 #3248323
相关文献 (1)
openreactiondata ↗doi:10.6084/m9.figshare.5104873.v1; patent:US08969359B2
反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.
实验步骤: To a stirring solution of 3-fluoro-2-tetrahydrofuran-2-yl-aniline (16) (131.9 g, 92%, 669.7 mmol) in methyl tert-butyl ether (1.456 L) and acetonitrile (485 mL) cooled to −20° C. was added N-bromosuccinimide (120.4 g, 99%, 669.7 mmol, Aldrich B81255) in 3 portions maintaining a reaction temperature below about −15° C. After complete addition stirring was continued at −15 to −10° C. for 30 minutes. 1H NMR of a worked-up aliquot showed 96% consumption of starting aniline so added another 4.82 g NBS and stirred at −10° C. for another 30 minutes. Aqueous 1 N Na2S2O3 (670 mL) was added to the reaction mixture. The cold bath was removed, the mixture stirred for 20 minutes, then diluted with EtOAc. The layers were separated and the organic phase was washed with saturated aqueous NaHCO3 (2×), water, brine, dried over Na2SO4, decanted, and concentrated under reduced pressure giving a dark amber oil. The residue was diluted with hexane and eluted through a short plug of silica eluting with 25% EtOAc/hexane to 50% EtOAc/hexane. The desired filtrate was concentrated in vacuo giving 17 as a dark amber oil (182.9 g, 90% yield; 86% NMR purity). LCMS (C18 column eluting with 10-90% CH3CN/water gradient over 5 minutes with formic acid modifier) M+1: 260.12 (3.20 min). 1H NMR (300 MHz, CDCl3) δ 7.15 (dd, J=8.6, 7.6 Hz, 1H), 6.30 (dd, J=8.7, 1.3 Hz, 1H), 5.19-5.12 (m, 1H), 4.58 (s, 2H), 4.16-4.07 (m, 1H), 3.90-3.81 (m, 1H), 2.23-1.99 (m, 4H) ppm. maintaining a reaction temperature below about −15° C After complete addition 96% consumption of starting aniline so added another 4.82 g NBS stirred at −10° C. for another 30 minutes Aqueous 1 N Na2S2O3 (670 mL) was added to the reaction mixture The cold bath was removed the mixture stirred for 20 minutes diluted with EtOAc The layers were separated the organic phase was washed with saturated aqueous NaHCO3 (2×), water, brine dried over Na2SO4 decanted concentrated under reduced pressure giving a dark amber oil eluted through a short plug of silica eluting with 25% EtOAc/hexane to 50% EtOAc/hexane The desired filtrate was concentrated in vacuo
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