To a solution of compound 2-iodo-4-(1-methyl piperidin-4-yloxy)-9,10-dihydro-4H-3,10a-diaza-benzo[f]azulene (example 2A) (50 mg, 0.12 mmoles) in 1,4-dioxane (0.5 mL) in a screw-capped vial under argon are added DIEA (31 μL, 0.18 mmole), benzylmercaptan (21 μL, 0.18 mmole), bis(dibenzilideneacetone)Palladium(0) (3.5 mg, 6 μmole), Xantphos (3.5 mg, 6 μmole). The reaction mixture is heated at 120° C. overnight. As the reaction is not complete, bis(dibenzilideneacetone)Palladium(0) (3.5 mg, 6 μmole), Xantphos (3.5 mg, 6 μmole) are added to the reaction mixture. After one overnight at 120° C., water is added to the reaction mixture and pH adjusted to 9-10 by adding concentrated ammonia solution. The aqueous phase is extracted three times with CH2Cl2. The organic phase is dried over magnesium sulphate, filtered and the solvent is removed under reduced pressure. The residue is purified by silica gel chromatography using (CH2Cl2:MeOH:NH4OH) as eluent with a gradient from (98:2:0.1) to (96.5:3.5:0.35) to afford 2-benzylsulfanyl-4-(1-methylpiperidin-4-yloxy)-9,10-dihydro-4H-3,10a-diaza-benzo[f]azulene.
