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Abstract

The present invention relates to a process for the synthesis of monohaloalkanoylferrocenes of general formula (I) ##STR1## in which X=Cl, Br, n is an integer such that 2.ltoreq.n.ltoreq.7, R.sub.1 and R.sub.2 =H, C.sub.1 -C.sub.8 alkyl chain. A ferrocene derivative of general formula (II) ##STR2## in which R.sub.1 and R.sub.2 have the abovementioned meaning, is reacted at a temperature -5.degree. C.<.theta..sub.r <+15.degree. C., in the presence of AlCl.sub.3 with a halide or the anhydride of an acid of general formula (III) HOOC--(CH.sub.2).sub.n --X, X and n having the abovementioned meaning. An acylating solution obtained by mixing AlCl.sub.2 and the acid halide or anhydride in CH.sub.2 Cl.sub.2, whose temperature .theta..sub.a is such that 5.degree. C..ltoreq..theta..sub.r -.theta..sub.a .ltoreq.15.degree. C., is progressively added to a solution of the ferrocene derivative (II) in CH.sub.2 Cl.sub.2. The molar ratio of the acid halide or anhydride to the ferrocene derivative is between 0.99 and 1.01 and that of AlCl.sub.3 to the ferrocene derivative between 1.05 and 1.11. The mixture is then hydrolyzed and the crude product (I) is recovered by filtration followed by evaporation of CH.sub.2 Cl.sub.2. This process enables a crude synthetic product to be obtained in a yield and with a purity which are high. The monohaloalkanoylferrocenes (I) are synthesis intermediates in pharmacy and in self-propulsion.

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First Claim