反应 #465963

反应方程式

methyl 4-amino-3,6-dichloropyridine-2-carboxylate

bromine

→

4-amino-3,6-dichloro-5-bromopyridine-2-carboxylic acid

收率 91.0%

溶剂

sulfuric acid

反应条件

后处理

1. 1
   温度to cool to room temperature
2. 2
   萃取extracted with EtOAc (4×500 mL)
3. 3
   干燥The combined organic extracts were dried (MgSO4)
4. 4
   过滤filtered
5. 5
   浓缩concentrated
6. 6
   其他to yield a brown solid
7. 7
   其他The crude product was purified via reverse phase HPLC (50% acetonitrile/water)

实验过程

To a solution of methyl 4-amino-3,6-dichloropyridine-2-carboxylate (18 g, 81 mmol) in 100 mL fuming sulfuric acid was added bromine (15 mL, excess). The resulting mixture was heated to 70° C. for 30 min, then allowed to cool to room temperature. This material was poured into ice water (1000 mL) and extracted with EtOAc (4×500 mL). The combined organic extracts were dried (MgSO4), filtered and concentrated to yield a brown solid. The crude product was purified via reverse phase HPLC (50% acetonitrile/water) to give 21 g of 4-amino-3,6-dichloro-5-bromopyridine-2-carboxylic acid as a white solid (91% yield); mp 201-202° C.

来源