反应 #7064

反应方程式

2-amino-4-chlorobenzoic acid

hydrobromic acid

sodium nitrate

→

title compound

收率 59.0%

2-Bromo-4-chlorobenzoic acid

收率 59.0%

溶剂

water

water

water

反应条件

后处理

1. 1
   温度cooled
2. 2
   workup.ADDITIONUpon the completion of the addition
3. 3
   萃取After extraction with ethyl acetate/hexanes (3:1; 2×400 mL)
4. 4
   洗涤the combined organic layers are washed with brine (200 mL)
5. 5
   其他dried
6. 6
   浓缩concentrated
7. 7
   其他chromatographed on silica (1% methyl alcohol and 0.5% acetic acid in chloroform)

实验过程

An aqueous solution of sodium nitrate (2.21 g) in water (15 mL) is added dropwise to a stirred, ice-cooled mixture of 2-amino-4-chlorobenzoic acid (5.00 g, 29.1 mmol) and 48% hydrobromic acid (150 mL) in water (150 mL). The resultant mixture is stirred for 2 hr at 0° C. Then it is treated dropwise with an aqueous solution of copper bromide (7.81 g) in water (20 mL). Upon the completion of the addition, the reaction mixture is allowed to warm to ambient temperature where it is stirred overnight. After extraction with ethyl acetate/hexanes (3:1; 2×400 mL), the combined organic layers are washed with brine (200 mL), dried, concentrated, and chromatographed on silica (1% methyl alcohol and 0.5% acetic acid in chloroform) to give the title compound (4.04 g, 59% yield). mp 154–155° C.; ES(−)MS m/z 233, (M−H)− consistent with 1 Br an 1 Cl.

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