Appeal decision T0728-98



Main request : “1. A substantially pure piperidine derivative compound of the formulae:
R1 is hydrogen or hydroxy;
R2 is hydrogen;
or R1 and R2 taken together form a second bond between the carbon atoms bearing R1 and R2;
R3 is -COOH or -COOR4;
R4 is an alkyl with 1 to 6 carbon atoms;
A, B and D can be one or more different substituents of their rings and are individually hydrogen, halogens, alkyl, hydroxy, alkoxy, or other substituents or a salt thereof.”

Article 84 EPC
There does not exist any unequivocal generally accepted meaning in the relevant art for the feature "substantially pure", with the consequence that this feature casts doubts as to the actual subject-matter covered by the claim. Yet, this unclear feature is the sole feature designed for distinguishing the subject-matter claimed from the prior art document (1). On the ground of that lack of legal certainty, in the Board's judgment, claim 1 according to the main request is not clear.

Article 123(2) EPC
In several auxiliary requests, the feature “substantially pure” has been deleted. The application as filed presents the feature "substantially pure" defining the piperidine compounds as being the sole essential feature of the invention. Thus, the omission of that essential feature in independent claim 1 as amended according to auxiliary requests amounts to an undue generalisation by extending thereby the purity of the piperidine compounds to any level.
Therefore, the skilled man is presented with information which is not directly and unambiguously derivable from the application as filed. The Board concludes that claim 1 according to auxiliary requests extends the subject-matter claimed beyond the content of the application as filed, thus contravening Article 123(2) EPC.

In another auxiliary request, claim 1 is restricted with 4-[4-[4-(hydroxydiphenylmethyl)-1-piperidinyl] -1-hydroxybutyl]-Alpha, Alpha-dimethylbenzeneacetic acid being the piperidine compound and with the individual piperidine being obtainable by a particular multi step preparation process.
A claim for a chemical product defined in terms of a process for its preparation is patentable only if the product itself fulfils the requirements for patentability, i.e. in particular if it is new and involves an inventive step.
Thus, it has to be examined whether or not a different level of chemical purity imparts novelty to the claimed subject-matter over document (1).
According to the jurisprudence of the Boards of Appeal, the level of purity of a low molecular chemical compound, as a general rule, cannot entail novelty since conventional methods for its purification are within the common general knowledge of the skilled person. The appellant alleged that this general rule would not apply in the present case since this case is an exceptional situation wherein all attempts failed to achieve a particular level of purity by conventional purification methods.
According to the appellant, the result of the preparation process known from document (1) was a mixture of meta/para-regioisomers being inseparable by standard techniques; thus, it was not possible to obtain that individual piperidine compound, which was the para-regioisomer, in the highly pure form as claimed using a conventional purification method.
The application as filed (page 6, first paragraph) and document (E4) (section 9), reveal that it is in fact possible by means of HPLC to separate that mixture of meta/para-regioisomers known from document (1) into the different pure regioisomers and to obtain significant, even if small, quantities of the substantially pure para-regioisomer which is the individual piperidine compound as defined in present claim 1. HPLC is a standard technique for purifying low molecular chemical compounds belonging to common general knowledge.
No novelty.

Decision here


This website uses cookies

This website uses cookies to improve user experience. By using our website you consent to all cookies in accordance with our Cookie Policy.