Benzyl 1-methyl-1H-indole-6-carboxylate (from (b), 9.8 g) and 2-(1,3-benzodioxol-5-yl)-2-bromoacetic acid (from Preparation 1, 10.5 g) were stirred together in dimethylformamide (100 ml) and a steady stream of nitrogen was passed through the solution which was warmed to 90° C. After 4 h the reaction mixture was cooled to room temperature and the dimethylformamide removed in vacuo. The oily residue was partitioned between ethyl acetate (300 ml) and 2M hydrochloric acid and the organic phase was washed with more 2M hydrochloric acid (3×50 ml) and brine (50 ml). The organic phase was dried (MgSO4) and decolourising charcoal was added. The slurry was filtered and concentrated to give an orange oil. Flash column chromatography (gradient elution from 100% CH2Cl2 to 95% CH2Cl2/5% MeOH) gave 9.97 g of the subtitle compound.
