To methanesulfonic acid (8 ml) in a flask under N2 was added P2O5 (0.56 g), the resulting suspension was heated to 60° C. until a clear solution formed. The mixture was cooled to room temperature prior to addition of 4-methoxy-3-methyl-phenylacetic acid (0.3549) and 4-methyl-2-[4-(trifluoromethyl)phenyl]thiophene (intermediate 102, 0.4 g). The mixture was then heated to 60° C. for 90 minutes. The reaction mixture was cooled to room temperature and then poured into iced water. The suspension was made basic by cautious addition of NaHCO3 and the products extracted into ethyl acetate. The combined organic extracts were dried (MgSO4), filtered and evaporated to yield a brown oil. Purification by flash column chromatography eluting with 5% EtOAc/cyclohexane yielded the title compound as a brown gum.
