N-bromobutanimide → 6-Bromo-4H-furo[3,2-b]pyrrole-5-carboxylic acid methyl ester

To a cold solution (ice-water bath) of methyl 4H-furo[3,2-b]pyrrole-5-carboxylate (1.0 g, 6.05 mmol) in DCM (10 mL) was added TBAF (1.0 M in THF, 9.0 mL, 9.0 mmol) and NBS (1.5 g, 7.9 mmol). The resulting dark colored solution was stirred from 0° C. to rt overnight. The reaction mixture was diluted with 50 mL of CH2Cl2 and washed with water (100 mL) and brine (100 mL) and dried (Na2SO4). After filtration, the filtrate was concentrated by evaporation and the crude product was purified by silica gel chromatography (0-5% EtOAc/hexane) to afford a white solid. 1H NMR (400 MHz, CDCl3) δ (ppm) 8.84 (broad, 1H, NH), 7.54 (d, J=2.2 Hz, 1H), 6.48 (d, J=1.83 Hz, 1H), 3.92 (s, 3H) ppm; m+/z 244 (100%), 246 (100%).

1. washwashed with water (100 mL) and brine (100 mL)
2. dry with materialdried (Na2SO4)
3. filtrationAfter filtration
4. concentrationthe filtrate was concentrated by evaporation
5. customthe crude product was purified by silica gel chromatography (0-5% EtOAc/hexane)
6. customto afford a white solid

ORD 기록

ord-05c46f1a29ae460fbb5ba364793e2caf

출처 데이터셋

uspto-grants-2011_02

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US07884124B2