In T 288/92 the board held that it was not permissible to amend a generic formula defining a class of chemical compounds by restricting an originally disclosed generic definition of a substituent to a specific (individual) one which was arbitrarily selected from chemical entities, such as in the examples, without some support for such restriction in the general part of the description (see also T 1537/14).
Source: http://www.epo.org/law-practice/legal-texts/html/caselaw/2019/e/clr_ii_e_1_10_3.htm
Date retrieved: 17 May 2021