反应详情

To a stirred solution of [2,3-dichloro-4-(6-ethyl-3-oxo-1-cyclohexen-1-yl)phenoxy]acetic acid (2.06 g, 0.006 mole) under nitrogen in tetrahydrofuran (THF) (50 ml) was added 1,1'-carbonyldiimidazole (0.97 g, 0.006 mole). The solution was stirred for 1 hour then 2-hydroxy-2-methylpropanoic acid (0.62 g, 0.006 mole) in THF (25 ml) was added and stirring was continued overnight. The THF was evaporated in vacuo and the residue chromatographed on silica (300 g) eluting with CH2Cl2 -THF-AcOH (100:2:1). Evaporation of the pertinent fractions gave 1-carboxy-1-methylethyl [2,3-dichloro-4-(6-ethyl-3-oxo-1-cyclohexen-1-yl)phenoxy]acetate which melted at 167°-168° C.

1. stirringstirring
2. waitwas continued overnight
3. customThe THF was evaporated in vacuo
4. customthe residue chromatographed on silica (300 g)
5. washeluting with CH2Cl2 -THF-AcOH (100:2:1)
6. customEvaporation of the pertinent fractions