halogenating agent such as thionyl chloride or phosphorus pentachloride and condensing it in the presence of an appropriate base; or a process wherein a carboxylic acid of formula (III) is converted into an acid anhydride with p-toluenesulfonyl chloride, ethyl chlorocarbonate, pivaloyl chloride or the like and then the acid anhydride is condensed in the presence of an appropriate base. [0034] In c