5-iso-Butyl-2-(N-tert-butylaminosulfonyl)thiophene-3-boronic acid (0.479 g, 1.5 mmol, see Example 1(c) above), 1-(4-bromobenzyl)-1H-[1,2,4]triazole (0.238 g, 1 mmol, see step (a) above), Pd(OAc)2 (15.7 mg, 0.03 mmol), triphenyl phosphine (15.7 mg, 0.06 mmol) and NaOH (0.16 g, 4 mmol) were dissolved in 4 mL of toluene/ethanol (4:1) in a thick walled glass tube, and were then heated to 80° C. for 1 h. The reaction mixture was cooled to rt, extracted with ethyl acetate and water and subsequently dried over K2CO3. The solvent was evaporated and the reaction mixture was separated on a silica column (dichloromethane+1% methanol to dichloromethane+4% methanol) to yield 0.288 g of the sub-title compound (65% yield).
