反应 #3193

反应方程式

HBr

1,2-dimethoxy-4,5-dinitrobenzene

→

product

1,2-Dihydroxy-4,5-dinitrobenzene

溶剂

acetic acid

反应条件

后处理

1. 1
   温度the reaction was slowly heated to reflux
2. 2
   萃取extracting the aqueous phase with CHCl3 (3×150 mL) in order
3. 3
   其他to remove any organic impurities
4. 4
   萃取The dinitro catechol was extracted out of the aqueous layer with ethyl acetate (3×150 mL)
5. 5
   洗涤The combined ethyl acetate extracts were washed with water and brine (3×100 mL)
6. 6
   干燥dried over MgSO4
7. 7
   浓缩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
    其他The light yellow needles that formed
11. 11
    过滤were filtered
12. 12
    洗涤washed with dichloromethane

实验过程

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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