To a solution of 7-chloro-4-iodo-3-methyl-pyrrolo[2,3-c]pyridine-1-carboxylic acid tert-butyl ester (2 g) in dry tetrahydrofuran (40 ml) was added 4 A molecular sieves. The solution was stirred at room temperature for 15 minutes then cooled to 40° C. Under an atmosphere of nitrogen was added dropwise, a solution of isopropylmagnesium chloride (2M in tetrahydrofuran, 5.4 ml) and the solution stirred at −40° C. for 10 minutes. The solution was saturated with a stream of carbon dioxide gas which had been passed through a column of Drierite and then diluted with ethyl acetate. The organic was extracted with 1N sodium hydroxide solution until complete extraction and the combined aqueous was then acidified to pH1 with concentrated hydrochloric acid. The acidified aqueous was extracted twice with ethyl acetate which was combined and washed with water until neutral. The ethyl acetate layer was then dried (MgSO4) and evaporated to give a solid. The solid was triturated with isohexane, filtered off and washed with isohexane. The solid was sucked dry then dried at 50° C. under vacuum to afford the title compound (1.22 g).
