<p><em>The cashew nut shell liquid (CNSL) is an important source of phenolic compounds such as anacardic acids, cardols and cardanols. These compounds present many biological activities. The components of CNSL were isolated and purified by column chromatography. Cardanol was employed as starting material for a methathesis reaction making use of Grubbs 1<sup>st</sup> generation catalyst, under nitrogen atmosphere, in dichloromethane, heating at 50 <sup>o</sup>C and, magnetic stirring during 98 h. The product biscardanol is a key-intermediate for the synthesis of new bis thioxanthones.</em></p