反応 #3193

反応方程式

HBr

1,2-dimethoxy-4,5-dinitrobenzene

→

product

1,2-Dihydroxy-4,5-dinitrobenzene

溶媒

acetic acid

反応条件

後処理

1. 1
   温度the reaction was slowly heated to reflux
2. 2
   抽出extracting the aqueous phase with CHCl3 (3×150 mL) in order
3. 3
   その他to remove any organic impurities
4. 4
   抽出The dinitro catechol was extracted out of the aqueous layer with ethyl acetate (3×150 mL)
5. 5
   洗浄The combined ethyl acetate extracts were washed with water and brine (3×100 mL)
6. 6
   乾燥dried over MgSO4
7. 7
   濃縮concentrated to an orange residue
8. 8
   workup.ADDITIONApproximately 100 mL of dichloromethane was added to the residue
9. 9
   workup.WAITplaced in the freezer for several hours
10. 10
    その他The light yellow needles that formed
11. 11
    ろ過were filtered
12. 12
    洗浄washed with dichloromethane

実験手順

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.

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