Recently the LATL has undertaken the development of a multilingual translation system based on a symbolic parsing technology and on a transfer-based translation model. A crucial component of the system is the lexical database, notably the bilingual dictionaries containing the information for the lexical transfer from one language to another. As the number of necessary bilingual dictionaries is a quadratic function of the number of languages considered, we will face the problem of getting a large number of dictionaries. In this paper we discuss a solution to derive a bilingual dictionary by transitivity using existing ones and to check the generated translations in a parallel corpus. Our first experiments concerns the generation of two bilingual dictionaries and the quality of the entries are very promising. The number of generated entries could however be improved and we conclude the paper with the possible ways we plan to explore.