除草剂炔草酯的合成研究

以5氯2,3二氟吡啶与(R)2(对羟基苯氧基)丙酸为原料,以二甲基甲酰胺(DMF)为溶剂,K2CO3为缚酸剂,在70℃下醚化反应4h,然后再加入氯丙炔,以甲苯为溶剂,反应温度70～75℃,降温后过滤除盐,DMF洗涤,脱溶,再用乙醇/水结晶,干燥得产品,含量98%,以(R)2(对羟基苯氧基)丙酸计总收率86%。

Synthesis of the herbcidal chodinafop-propargyl

Chodinafop-propargyl was synthesized from R-2-(p-hydroxyphenoxy)-propionic acid and 5-chloro 2,3-difluoropyridine and propargyl chloride. At first R-2-(p-hydroxyphenoxy)-propionic acid was converted into the corresonding potassium with potassium carbonate powder and tetrabutyl ammonium bromide in DMF at 70℃,then 5-chloro–2,3-difluoropyridine was added over course of 30 min ,after 4 hours, propargyl chloride was added over 2 hours to form the (R)(+)-2-4-(5-chloro-3-fluoropyridin-2-yloxy)-phenoxy]-propionic acid propinyl ester. Filtered,washed with DMF,evaporatored under vacuum ,recrystalled with ethanol/water,dried under vacuum at 30℃, Chodinafop-propargyl was obtained with a content 98%(HPLC) and the total yield 86% based on R-2-(p-hydroxyphenoxy)-propionic aci.