T 0065/82 (Cyclopropane) 20-04-1983

1. The appeal complies with Articles 106 to 108 and Rule 64 EPC and is, therefre, admissible.

2. The new end products and their preparation according to Claims 1 and 2, as well as the appropriate formulation against insects and spiders and the preparation thereof (Claims 7 to 10) were already recognised as patentable by the Examining Division (cf. Communication of 10 April 1981). The chemical compounds according to formula I represent a selection from a large calss of esters (DE-A-2 738 150 (page 2)). As far as there is any overlap, the new products of Claim 1 are differentiated from those in the state of the art not only by the limited possibilities of substitution on the acid and alcohol parts of the molecule, but also by having a bromo-atom in a certain position. Evidence was submitted to substantiate that these agents exhibit a surprisingly better effect in comparison with structurally close compounds.

3. Claim 3 (formula II) defines, on the other hand, a corresponding class of bromostyril-cyclocarbonic acids, which can, as intermediates, be transformed into acid derivatives (e.g. acid chlorides which according to page 10 of the application are likewise new) which can then be directly converted through esterification into the end products according to formula I. The claimed acids also represent a selection from a known class (cf. DE-A-2 738 150, page 4; hydrolysed products of compounds according to formula I-a) without specifically including known variants. The selected sub-class is not a mere sample of the whole taken purely at random from the field of possibilities, without further technical significance. On the contrary, all members of the sub-class show a property, which is not represented by the class of compounds according to the original fomula I-a of the citation, namely the assured capability of being convertible into the advantageous end products according to formula I. Claim 3 presents, therefore, a distinctive class with a peculiarity indicating the absence of identity with the original class and thereby confirming its novelty as a class.

4. The selected intermediates must themselves be based on an inventive step in order to be patentable. The prior art closeto these intermediates (e.g. DE-A-2 738 150) discloses no specific compounds which would be suitable to deliver the same desired products according to formula I by means of the same processes, in the same manner as the compounds specified in formula II. There is nothing in the previously-published citations raised in the search report which could direct the skilled man towards the structures according to formula II which are necessary for the purpose of preparing the products according to formula I. It is clear, therefore, that the intermediates according to Claim 3 are not derivable from such "close-to-the-intermediate" state of the art.

5. It is also recognisable that the specifically modified intermediates of the application under appeal are unsuitable for the preparation of the structurally close subsequent products disclosed in the prior art through any kind of analogy processes. Conversely, it can be concluded that the claimed intermediates cannot be derived in an obvious manner from the "close-to-the- product" state of the art. In particular, compounds according to formula II carry substituents of the 2-bromo-atom and the selected substituents on the phenyl group which are incorporated in the subsequent products according to formula I and contribute to the set of features which differentiate the latter from the compounds described in any of the cited documents.

6. Intermediates which are suitable for the preparation of patentable subsequent products normally contain two essential parts. The first is a collection of those structural elements which are directly incorporated in the product ("structural contribution"). The second part represents those features, e.g. radicals, atoms or bonds which are removed or disappear in the reaction ("split-off-parts"). In the case of analogy processes, i.e. processes which are in themselves obvious, the manner of incorporation is completely forseeable and, therefore, predetermined. The suitability for conversion in the analogy process is deducible from general knowledge in the field on the basis of the structure and particularly of the nature of the split-off parts. In one respect or another, all compounds are "known" potential intermediates for certain analogy processes. The skilled person can also deduce the equivalents of a known compound as an alternative intermediate in this respect by notionally replacing one split-off part with another performing the same function. Whilst such novel alternative variants may also be suitable for making a large number of derivatives by means of particular analogy processes, each result is predictably identical with that obtainable by the use of the known intermediate. The issue is solely whether or not one can obtain a particular product in such a way. If so, the same property, i.e. capability, takes effect in both cases. It is very relevant in this respect that, whenever a known compound possesses an already recognised capability, the patentability of new close structural analogues which take advantage of that capability must be established by comparison. This should show that the structural modifications represented by the new variants had a technical relevance by bringing about a surprising difference in the effect. This is in contrast to the case where a new type of use is discovered, i.e. new properties for the new variants, which use has been completely unforseeable beforehand. No comparison with the prior art is therefore necessary. Similarly, novel intermediates which are recognisably suitable for certain conversion reactions, should also exhibit a surprising comparative advantage over any known compound which can also deliver the same subsequent products by the same analogy processes. This may, for example, come from unexpected reactivity or surprisingly better yield ("process effect"), but not, in this instance, from the mere fact that certain new subsequent products could be equally well prepared from the new intermediates.

7. On the other hand, if there is no suitable intermediate available in the state of the art for the specific purpose, a compound already known in itself must first be appropriately modified to provide a "stepping-stone" for the desired analogy process. Typically, either the part contributing to the structure must be provided de novo, with any suitable reactive split-off parts, or where the contributory part is already known but is equipped with non-reactive parts, it must at least be equipped with reactive split-off parts. Neither of such purpose-directed modifications is foreseeable with regard to the "close-to-the- intermediate" state of the art without the knowledga of the problem of making the desired subsequent product. The intermediates according to Claim 3 represent, as already suggested, modifications, i.e. limitations of this kind.

8. Intermediates which are thus provided in a non-obvious manner as sole suitable means for the desired purpose, may nevertheless not necessarily be inventive in the light of citations from the state of the art relevant to the subsequent products of the intermediates in the case (i.e. the "close-to-the-product" state of the art). It would be anomalous if the skilled person could derive the same intermediates in an obvious manner from the very documents which serve as a basis for establishing the inventive character of the further products in relation to the "close-to- the-product" prior art. This would, for instance, be the case if the skilled man were able to envisage the claimed intermediates also as suitable intermediates in the preparation of the products disclosed in the citations and as capable of being directly prepared by analogy processes, even if this possibility was not expressly suggested. As explained, this is not the case with the intermediates according to Claim 3.

9. In terms of the technical process involved, such "close-to- the-product" prior art has particular relevance in the case of structurally similar compounds. The presentation of directly derivable intermediates, obviously also suitable to deliver the structural part of the closest analogues and homologues, which is unmodified and still identical with a structural part of the subsequent product in the case, can hardly be surprising in itself. From the above requirement that the intermediate must not be derivable from the "close-to-the-product" prior art it follows that the contribution to structure must carry at least one of the characteristics which differentiate the subsequent products from the compounds in the "close-to-the-product" prior art ("contribution to structural differentiation").

10. The basic problem underlying the invention according to Claim 1 is to produce an insecticidal or acaricidal effect. The solution to this kind of problem emerges directly from an interaction, i.e. a process which provides the desired result. If the agent used for that purpose is also novel, it could be regarded as an (indirect) answer to the problem. If so, the need for its preparation by an analogy process would constitute a further, as yet unrecognised problem. The solution to such a problem may take the form of a patentable intermediate, depending on the state of the art, as already suggested above. The problem solved by the provision of the intermediate lies exclusively in making possible the subsequent product itself, and not in the properties of the latter or in the outcome of its surprising effectiveness in use. A causality of this kind is sufficient to satisfy the general requirement that the patentable solution and its effect must have a causal relationship. The non-obvious cahracter of the effect of the intermediate can be maintained so long as the posing of an as yet not generally recognised problem is still valid. Hovewer, the task of providing a patentable subsequent product would necessarily disappear, if it turned out that the product is not novel or has no surprising effect, i.e. that there is no technical teaching involved. It follows from these considerations that there is no justifiable reason to distinguish between various kinds of patentable subsequent products on the basis of their use, i.e. whether or not they are end products or are themselves intermediates of one kind or another.

11. Since it furthermore follows from these considerations that the intermediate must also contribute to the characteristics of the subsequent product which differentiate the latter from the relevant state of the art, it could be interpreted as a precursor and thus as a true "condition sine qua non" for the latter. Whilst the use of a novel intermediate may have been an actual "condition" in the preparation of the subsequent product, this circumstance would not necessarily imply that there was a need for a "stepping-stone" on this specific route. The necessity for particular unforseeable structural modifications to any close art with a corresponding change in capabilities confirms the inventive character of the provision of such intermediates.

12. It follows from the above that novel intermediates which are suitable for conversion into patentable subsequent products and which contribute at least a part of their structure thereto through an analogy process, are not automatically patentable, i.e. irrespective of the state of the art. With respect to the "close-to-the-intermediate" state of the art, the question is whether or not the skilled man could have deduced from it the need to carry out certain purposive modifications to known compounds in order to obtain that intermediate which alone could enable him to solve the problem of making the subsequent products by means of an analogy process. Since the assumption is that this problem does not exist in the prior art, the answer must be in the negative, provided there is no compound already available which reacts in the same manner with substantially identical results. With respect to the "close-to-the-product" state of the art, the second question then is whether or not the skilled man could have derived the same intermediate from the disclosure of the cited art close to the further product in an obvious fashion. If the answer is again in the negative, this should normally imply also a "contribution to the structural differentiation" with regard to the subsequent product, and the intermediate can, as in the case of the present appeal, be recognised as representing an inventive step having regard to the state of the art.

13. The products according to the broadest independent Claims 1 and 3 are technically interrelated and therefore have unity within the meaning of Article 82 EPC. The solution to the problem underlying the first invention, the subsequent products according to Claim 1, leads directly to the further problem of their preparation by means of esterification with appropriate acids or acid derivatives. The overlap between the solutions to the problem and the effects of the two contiguous inventions forms the basis for the unity of the common general inventive concept.