| 摘要 |
PURPOSE:The dehalogenation of a propionic acid ester is carried out using a specific amount of aqueous solution of an alkali metal oxide for a certain time to enable easy and high-yield production of the titled compound with industrial advantage. CONSTITUTION:25-55wt% aqueous solution of an alkali oxide such as sodium hydroxide is added to a propionate of formula I (X1, X4 are halogen; X2, X3 are H, X1, X4; R is alkyl, aryl) at a molar ratio of 1:(0.9-2.0) at 0-80 deg.C over 0.5-5.0hr continuously or intermittently to effect dehydrohalogenation to give the objective compound of formula II. EFFECT:The reaction process is easily controlled to inhibit side-reactions such as hydrolysis and saponification. Further, the hydrogen halide removed immediately reacts with the alkali metal hydroxide to form a halide and the halide dissolves in the reaction medium. Thus, troublesome operations are not needed, after reaction. USE:A starting material of agricultural chemicals and medicines, a starting material of a polymer for UV photoresist.
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