T 0648/88 ((R,R,R)-Alpha-tocopherol) 23-11-1989
Download und weitere Informationen:
1. The same criteria which are generally decisive for determining whether the preparation of a new chemical substance is to be regarded as inventive should in prinicple also be applied when a substance in question is an intermediate. Here the sole determination factor is whether or not its preparation enhances the art in a non-obvious way.
2. An intermediate intended for the preparation of a known end product is deemed to be inventive if its preparation takes place in connection with inventive preparation or inventive further processing, or in the course of an inventive complete process (further to T 22/8, "Bis-epoxy-ethers/BASF", OJ EPO 1982,342.)
Inventive step (yes)
Intermediates in an inventive complete process
Further processing as such not inventive
Summary of Facts and Submissions
I. On 19 December 1984, European patent No. 76 448 was granted on European patent application No. 82 108 913.3 filed on 27 September 1982 claiming the priority of an earlier German application dated 2 October 1981. The claims of the granted patent were as follows (Claim 1 reproduced in abridged form): "1. A process for the preparation of (2R,6R)-1-chloro-2,6,10- trimethylundecane of the formula ... (i) wherein (a) the novel (r)-(+)-ß-chloro-isobutyric acid of the formula ... (II) is used as the optically active starting material, (b) this starting material is reduced ... to give (r)-(-)-3- chloro-2-methyl-propanol of the formula ... (III), (c) this compound is brominated ... to give the novel (s)-(+)-1- bromo-3-chloro-2-methyl-propane of the formula ... (IV), (d) this compound is converted into the novel (2R)-(+)-1-chloro- 2,6-dimethylheptane of the formula ... (v), (e) the product in (d) is converted into (3R)-3,7-dimethyl-octan- 1-ol of the formula VI ..., (f) the product in E is brominated ... to give (3R)-1-bromo- 3,7-dimethyloctane of the formula ... (VII) and (g) this compound is converted ... into the corresponding Grignard compound, which can be reacted ... to give (i).
2. (r)-(+)-ß-chloro-isobutyric acid (II).
3. (s)-(+)-1-bromo-3-chloro-2-methylpropane (IV).
4. (2R)-(+)-1-chloro-2,6-dimethylheptane (v).
5. Use of the compounds claimed in Claims 2 to 4 as optically active units for synthesising the side chains of (R,R,R)-|- tocopherol."
II. On 13 September 1985 the present respondents filed notice of opposition to grant of the patent, requesting that Claims 4 and 5 be revoked for lack of inventive step. Their opposition was based on two documents already cited in the contested patent specification, from which analogous bromine compounds and their preparation were known, so that the chlorine compounds, especially compound (v) claimed in Claim 4, were suggested. The documents in question were (1) DE-A-2 602 507 and (2) GB-A-1 456 830.
III. In an interim communication, the Opposition Division had expressed the opinion that Claim 4 should be deleted and Claim 5 amended accordingly. The present appellants thereupon contested this view and continued to defend the patent. The Opposition Division then revoked the patent in its entirety by its decision of 3 November 1988. In the Reasons for that latter decision it was accordingly stated that inventive step could generally be recognised for chemical substances only if their use was associated with unexpected effects. The fact that a production process for substances displayed inventiveness did not automatically mean that the substances themselves involved inventive step; this was the case only where there was prejudice in this regard or where particular difficulties were to be expected with their preparation. These considerations also applied to chemical substances when these were intermediate products: in this case an unexpected effect qualified as suitable for substantiating inventive step only if it arose in the course of further processing to arrive at an end product. In the absence of such an effect, preparation of the intermediate product had to be affected by a prejudice or entail almost insuperable difficulties. In this connection, reference was made to Board of Appeal decision T 163/84, "Acetophenone derivatives/Bayer" (OJ EPO 1987, 301), especially point 10 [of the Reasons]. In the present case the following conclusions were drawn from this: the racemate corresponding to compound (v) was known as a result of the contested patent specification, and though breaking it down might be difficult it was not to be regarded as ruled out; furthermore, (v) was recognisably obtainable in an analogous way to the bromine compound whose preparation was described in (1). On the other hand, there was nothing to indicate that further processing of (v) would be inventive. From these two points taken together it followed that Claim 4 did not contain any inventive step. As it had been the patent as granted which had been defended, the latter had had to be revoked in its entirety.
IV. On 20 December 1988 the appellants (patent proprietors) filed an appeal against the Opposition Division's decision, at the same time paying the prescribed fee. In their Statement of Grounds filed on 4 March 1989 they objected to the "discrimination" against intermediate products. In the case in question the inventive feature of (v) lay in the fact that its preparation opened the way to a more advantageous method of producing a desired end product. The cited decision T 163/84 had been interpreted incorrectly by the Opposition Division. The issue involved therein (inventive further processing of the intermediate to be protected) differed from the case in question, and other circumstances in which new intermediates were capable of protection were referred to merely by way of example and not in a definite form. Decision T 22/82, "Bis-epoxy ethers/BASF" (OJ EPO 1982, 341) had to continue to apply, and Decision T 163/84 was to be regarded as the follow-up because it was described as having been issued "further to" Decision T 22/82.
V. In the appeal proceedings the respondents neither made a submission nor commented on the matter.
VI. The appellants requested that the Opposition Division's decision be set aside and the patent maintained as granted, or alternatively that granted Claim 4 be deleted and granted Claim 5 amended accordingly. ...
Reasons for the Decision
1. The appeal complies with Articles 106 to 108 and Rule 64 EPC and is therefore admissible. ...
4. The Board agrees with the appellants regarding the principle that intermediate products in the patent law sense - i.e. chemical substances whose industrial applicability arises solely from their suitability for preparing other products having a "direct" industrial application - should not be "discriminated against", i.e. their patentability should not be measured by a different (more stringent) yardstick than that used for the actual products susceptible of "direct" industrial application. Neither the EPC nor the Implementing Regulations thereto offer any grounds for doing this because, insofar as the provisions refer to substances, no distinction is made between these two categories. It is true that in the nature of things the circumstances justifying non-obviousness in the case of intermediates are not on the same level as for end products: a chemical intermediate which becomes commercially usable only when converted into a particular end product does not exhibit an effect directly susceptible of industrial application as does the end product. However, in view of the conditions for patentability set out in Article 52(1) EPC this does not justify any fundamentally different way of assessing the inventive step of both categories of substances.
5. Board of Appeal case law took account of the foregoing by opening up the way to recognising the inventive step of an intermediate on the grounds of a "process effect". Thus, for example, in Decision T 22/82 (loc. cit.) the preparation of new intermediates for a surprisingly advantageous complete process for the preparation of known and desired end products was considered to be inventive. Decision T 163/84 (loc. cit.) given by a different Board of Appeal also acknowledged that such intermediates were patentable because their further processing to the known end products was judged to be inventive (see Reasons, points 3-6).
6. Decision T 163/84 did, however, express the opinion - in the form of an obiter dictum without giving detailed reasons - that a new chemical intermediate did not become inventive merely because it was prepared in the course of an inventive multi-stage process and was further processed to a known end product (cf. Reasons, point 10); there also had to be "other factors, such as that the process for preparing the new intermediate enabled it to be prepared for the first time and did so inventively, and other methods of preparing it appeared to be ruled out".
7. The Board giving the earlier Decision T 61/86 dated 2 December 1988 (unpublished) stated therein that it did not share this view but adhered to the line of argument marked out in Decision T 22/82 (cf. Reasons, points 5.5 and 5.6). The department of first instance has adopted the opinion expressed in Decision T 163/84 merely as an obiter dictum and - without giving any further reasons - has revoked the patent in essence because not even "at least one of the following essential patenting requirements" was fulfilled: either (a) the manner of preparation of the new intermediate had to make it available for the first time and do so inventively, and other methods of preparing it had to appear to be ruled out; or (b) the further processing of the intermediates had to be inventive.
8. The Board does not share this view. Under Article 56 EPC an invention is to be regarded as involving an inventive step if, having regard to the state of the art, it is not obvious to a person skilled in the art. For an invention involving a chemical substance this means that the preparation of the substance must lead to non-obvious, which is to say unexpected, enhancement of the art. More than that cannot be demanded. It is therefore illegal to make the inventive step involved with a chemical substance dependent on further conditions, as the decision under appeal proposes. As already stated, non-obvious enhancement of the art by preparation of a substance as a criterion for inventive step applies to chemical end-products and intermediates alike, i.e. regardless of how - that is to say with what "effect" (direct application effect or process effect) - the non-obviousness is substantiated. However, if the requirement decisive to recognition of inventive step in the case of a chemical intermediate is only that its manner of preparation enhances the state of the art in a surprising way, it can no longer matter whether the preparation of the said intermediate resulting in that enhancement occurred in connection with its inventive manner of preparation, its inventive further processing, or within the scope of an inventive complete process for preparing the end product.
9. The facts on which the contested decision is based are examined in detail below.
9.1 The closest state of the art is (1), which is taken as the point of departure in the contested patent specification (page 2, lines 36 et seq.). Citation (1) describes the preparation - through the hydrolysis or hydrogenolysis of cleavable ethers - of 1-hydroxy-2,6,10-trimethylundecane, a key substance in the synthesis of natural, optically active |-tocopherol (page 3 loc. cit.), and also various intermediates for the key substance, including the bromine analogues of compound (v) described in the contested patent (cf. page 16, penultimate paragraph).
9.2 In contrast, the problem which the invention sets out to solve is that of finding a new, technically less complex method of synthesis and new intermediates with whose help it is possible to obtain a known optically active key product which can be converted using a chroman-2-carboxaldehyde to give (2R,4'R,6'R)- -tocopherol, the natural, optically active vitamin E (cf. page 4, lines 63 to 65, of the contested patent). (The expression "key product" was chosen to avoid misunderstandings surrounding the terms "intermediate product" and "end product" since substance (i) - which is to be prepared in accordance with Claim 1, and is thus specifically aimed at - is on the one hand the technological "end product" of a multi-stage (B to G) process passing via several new process "intermediates" (II, IV, V), while on the other hand also being an "intermediate product" in the patent law sense - cf. Reasons, point 4.)
9.3 According to the proposal made in the contested patent, this problem is to be solved by means of the six-stage process described in Claim 1 and the resulting new intermediates (II), (IV) and (v) in Claims 2, 3 and 4 respectively. That the said proposal actually does solve the problem appears convincing to judge from page 5, line 62, to page 6, line 11, of the contested patent specification, especially in the light of the reduction in the number of process steps required (brought down to six from 15 to 17) and is also undisputed, making any further comments on this point unnecessary. The same applies with respect to novelty.
9.4 For the process described in the uncontested Claim 1 and also for the intermediates specified in the uncontested Claims 2 and 3, the inventive step is undisputed. In the opposition proceedings the respondents deliberately confined their attack on the patent to the subject-matter of Claims 4 and 5, thus acknowledging that there were no obstacles to patenting the subject-matter of Claims 1 (process), and 2 and 3 (preceding intermediates). In the present case - since there is nothing in the evidence offered to indicate otherwise - the Board therefore applies the same set of criteria when assessing Claims 4 and 5. It is then not clear, however, why the presence of inventive step should not also apply to the intermediate product described in Claim 4, because - to paraphrase the last sentence of point 7 of Decision T 22/82 - if the effect substantiating the inventive nature of the six-stage complete process is achieved via new intermediates made available in the course of the complete process, the "process effect" will also support the inventive step for the intermediates themselves, without which the advantageous complete process is not conceivable. It is not a matter of how close the structure of claimed chlorine compound (v) comes to its bromine analogues known from (1), or of whether it is in principle obtainable from the corresponding racemate - which is likewise already known according to page 2, lines 27 to 28, of the contested patent specification. What is decisive - as already stated above - is the fact that preparation of the intermediate in Claim 4 leads to a non-obvious enhancement of the art; this is the case here, since neither (1) nor (2) gives even the remotest pointer in the direction of the indisputably inventive complete process.
10. Where Claim 5 - also contested - refers back to Claims 2 and 3 it can stand for the same reasons as they; where it refers to Claim 4 it is based on the same inventive idea as that claim and is therefore likewise patentable. ...
ORDER
For these reasons it is decided that:
1. ...
2. ... the decision under appeal ... is set aside.
3. The opposition is rejected.