| 摘要 |
Enol halides corresponding to the skeletal formula <FORM:0981522/C2/1> or <FORM:0981522/C2/2> may be prepared by reacting with a halogenating agent serving to convert a carboxyl group into an acid halide group, in the presence of an alkali metal or alkaline earth metal halide, a compound corresponding to the skeletal formula <FORM:0981522/C2/3> or <FORM:0981522/C2/4> respectively where R represents a halogen atom, R1 and R3 represent an alkoxy, aralkoxy, aryloxy, alkylthio, aralkylthio or arylthio group or a primary, secondary, tertiary or heterocyclic amino group, R1 represents a hydrogen atom or an alkyl or aralkyl group or, optionally, a halogen atom where R1 represents a primary, secondary, tertiary or heterocyclic amino group, and R4 represents a hydrogen or halogen atom or an alkyl or aralkyl group. The halogenating agent may be phosphorus oxychloride and the metal halide may be lithium or magnesium chloride. Specifications 981,521 and 981,523 are referred to. |
