T 0065/82 (Cyclopropane) of 20.04.1983

I. New intermediates which take part in (non-inventive) analogy processes for the preparation of patentable subsequent products (i.e. end products or intermediates of various kinds), must - in order to qualify as intermediates - provide a structural contribution to the subsequent products. Even where this condition is met, such intermediates are not thereby unconditionally inventive, i.e. not without taking the state of the art into consideration.

II. As state of the art in relation to intermediates there are two different areas (see III and IV below) to be taken into account. One is (see III below) the "close-to-the-intermediate" state of the art. These are all compounds identified from their chemical composition as lying close to the intermediates. On the other hand (see IV below) the "close-to-the-product" state of the art must also be taken into account, i.e. those compounds identified from their chemical composition as lying close to the subsequent products.

III. 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 a specific 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.

IV. With respect to the "close-to-the product" state of the art, a further question then is whether or not the skilled man could have derived from it the claimed intermediate in an obvious fashion. If the answer is again in the negative, this implies that the intermediate makes a contribution to the structural differentiation of the subsequent product from that prior art. V.It is therefore (according to I) by definition a condition for the recognition of a product as an intermediate that it makes a structural contribution to the subsequent products. For inventive step to be recognised, a further requirement (according to III) is that no compound was available to the skilled man out of the "close-to-the-intermediate" prior art which could have fulfilled the same purpose equally well. Furthermore the intermediate must not (according to IV) be derivable in an obvious fashion from "close-to- the-product" compounds. The structural contribution provided by the intermediate must display at least one of those features which differentiate the subsequent products from the known compounds in the "close-to-the-product" prior art. The contribution must therefore be a "contribution to the structural differentiation".