Hydrogen Bromide → 4,5-Dinitrobenzene-1,2-diol

8B, FIG. 8. In a dry 500 mL round bottom flask, 1,2-dimethoxy-4,5-dinitrobenzene (3.2 g, 0.12 mmol) 8A was stirred vigorously in 40 mL of glacial acetic acid at 30° C. Once a homogeneous solution 200 mL of 48% HBr was added to the flask and the reaction was slowly heated to reflux. The reaction was complete as indicated by TLC after 4 hours. The work up involved pouring the cooled solution into 800 mL of ice water and then extracting the aqueous phase with CHCl3 (3×150 mL) in order to remove any organic impurities. The dinitro catechol was extracted out of the aqueous layer with ethyl acetate (3×150 mL). The combined ethyl acetate extracts were washed with water and brine (3×100 mL), then dried over MgSO4 and concentrated to an orange residue. Approximately 100 mL of dichloromethane was added to the residue and then placed in the freezer for several hours. The light yellow needles that formed were filtered and washed with dichloromethane to yield 2.37 g of product (84%). 1H NMR (d6 -acetone): δ3.45 (OH), 7.42 (Ar--H); 13C NMR (d6 -acetone): δ112.44, 137.00, 149.97, EI MS M+, 200.

1. temperaturethe reaction was slowly heated to reflux
2. extractionextracting the aqueous phase with CHCl3 (3×150 mL) in order
3. customto remove any organic impurities
4. extractionThe dinitro catechol was extracted out of the aqueous layer with ethyl acetate (3×150 mL)
5. washThe combined ethyl acetate extracts were washed with water and brine (3×100 mL)
6. dry with materialdried over MgSO4
7. concentrationconcentrated to an orange residue
8. additionApproximately 100 mL of dichloromethane was added to the residue
9. waitplaced in the freezer for several hours
10. customThe light yellow needles that formed
11. filtrationwere filtered
12. washwashed with dichloromethane

ORD 기록

ord-61d7db87905c47f9b370b8d2340da826

출처 데이터셋

uspto-grants-1998_03

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US05733903