반응 #322739

반응 방정식

hydrogen fluoride

methyl 2-[4-(3-amino-5-chloropyridin-2-yl-oxy)phenoxy]propionate

sodium nitrate

→

methyl 2-[4-(5-chloro-3-fluoropyridin-2-yloxy)phenoxy]propionate

수율 48.0%

반응 조건

후처리

1. 1
   workup.ADDITIONare added in portions at a temperature from -8° to 0° C
2. 2
   기타Excess hydrogen fluoride is removed by distillation
3. 3
   workup.ADDITIONthe residue is taken up in a mixture of 200 ml of methylene chloride and ice-water
4. 4
   추출The neutralised solution is extracted three times with methylene chloride
5. 5
   세척the organic extracts are washed with water
6. 6
   기타dried
7. 7
   농축concentrated by evaporation

실험 절차

A vessel is charged with 400 g (20 moles) of hydrogen fluoride and 167.4 g (0.518 mole) of methyl 2-[4-(3-amino-5-chloropyridin-2-yl-oxy)phenoxy]propionate are added in portions at a temperature from -8° to 0° C. 37.3 g (0.540 mole) of sodium nitrate are added over one hour and the mixture is stirred for two hours before it is slowly heated in an autoclave to 55° C. Excess hydrogen fluoride is removed by distillation and the residue is taken up in a mixture of 200 ml of methylene chloride and ice-water and the solution is neutralised with concentrated ammonia. The neutralised solution is extracted three times with methylene chloride and the organic extracts are washed with water, dried and concentrated by evaporation, affording 81.0 g (48% of theory) of methyl 2-[4-(5-chloro-3-fluoropyridin-2-yloxy)phenoxy]propionate with a melting point of 63°-64°.

출처