반응 #631978

반응 방정식

NaNO2

3-Amino-2-methylbenzoic acid

HBr

HBr

→

3-bromo-2-methylbenzoic acid

용매

H2O

반응 조건

후처리

1. 1
   workup.ADDITIONAfter the addition
2. 2
   여과filtered
3. 3
   여과The recovered filter cake
4. 4
   세척was washed first with water
5. 5
   건조with 10% HCl, and dried in air

실험 절차

3-Amino-2-methylbenzoic acid (6.16 g) was heated at reflux for 30 minutes in concentrated HBr. The mixture was cooled to 0° C. and treated with a solution of NaNO2 at 0° C. (2.8 g in 5.6 mL H2O). The resultant diazonium salt solution was slowly added to a preheated (60-70° C.) solution of CuBr (3.8 g) in 3.2 mL concentrated HBr. After the addition, the mixture was stirred overnight at room temperature and filtered. The recovered filter cake was washed first with water and then with 10% HCl, and dried in air to yield 6.93 g of 3-bromo-2-methylbenzoic acid as a light purple powdery solid. This material was dissolved in ethyl acetate, washed twice with 5% HCl dried over Na2SO4, and recrystallized from 4:1 hexanes:ethyl acetate first at room temperature and then under refrigeration. 1H NMR (DMSO, 200 MHz), δ (ppm): 7.72 (dd, 2H), 7.2 (t, 1H), 2.5 (s, 3H).

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