反应 #162563

反应方程式

2,5-difluoronitrobenzene

2-aminobutanoic acid

potassium carbonate

dimethyl sulfoxide

→

desired product

2-((4-fluoro-2-nitrophenyl)amino)butanoic acid

溶剂

water

反应条件

后处理

1. 1
   workup.WAITThe internal temperature of the mixture went up to ˜110° C. for 1 h
2. 2
   其他went down to 80° C.
3. 3
   workup.WAITAfter 23 h
4. 4
   温度the reaction was cooled to rt
5. 5
   洗涤The aqueous mixture was washed with diethyl ether (1 L×2)
6. 6
   其他to remove organic impurities
7. 7
   过滤The yellow solid was collected by filtration
8. 8
   洗涤washed with water (3 L)
9. 9
   其他air-dried

实验过程

A mixture of 2,5-difluoronitrobenzene (119 ml, 1.10 mol), 2-aminobutanoic acid (114 g, 1.10 mol), and potassium carbonate (152.2 g, 1.10 mol) in dimethyl sulfoxide (410 ml, 1.10 mol) was stirred at 80° C. for 23 h. ([Note 1]: The mixture had a deep orange red color. The internal temperature of the mixture went up to ˜110° C. for 1 h and then went down to 80° C.). After 23 h, the reaction was cooled to rt and carefully poured into water (2 L+1 L). The aqueous mixture was washed with diethyl ether (1 L×2) to remove organic impurities. The aqueous layer was then acidified to ˜pH 1.5 with concentrated HCl (300 mL) to generate a yellow solid. The yellow solid was collected by filtration, washed with water (3 L), and air-dried to give the desired product, a wet orange solid. The wet orange solid was recrystallized from 3 L toluene and stood at rt overnight to afford the desired product as an orange crystalline solid. The orange crystalline solid was filtered, washed with toluene (2 L), and dried under high vacuum at 80° C. for 4 h and then on lyophilizer overnight to afford 2-(4-fluoro-2-nitrophenylamino)-butanoic acid (203.6 g, 76.4% yield) as an orange crystalline solid. The orange crystalline solid was carried on without further purification to the next step.

来源