4-iodo-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazole → 7-Chloro-2-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazol-4-yl)thieno[3,2-b]pyridine

Participants

Reaction Conditions

Reaction Steps

To a solution of 2 (9.4 g, 56.0 mmol) in THF (150 ml) at −78° C. was added n-BuLi (28 ml, 70.0 mmol, 2.5 M soln in hexanes) and the reaction mixture was stirred at −78° C. for 45 mins. A solution of ZnCl2 (140 ml, 70.0 mmol, 0.5M in THF) was added and the reaction mixture was warmed to room temperature. To the warmed mixture a solution of 4-iodo-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazole [Carl J. Lovey et al, Tetrahedron Lett., 2004, 45(28), 5529-5532] (9.0 g, 28.0 mmol) and Pd(PPh3)4 (2.5 g, 2.1 mmol) in THF added. The reaction mixture was heated to reflux for 3 hrs, cooled to room temperature, quenched with aqueous ammonium hydroxide and made neutral with aqueous HCl. The neutral solution was extracted with EtOAc, the organic phase was collected, dried over anhydrous sodium sulfate and filtered. The filtrate was evaporated under reduced pressure and the residue was purified by column chromatography (eluent MeOH-EtOAc, 1:20) to afford the title compound 91 (7.5 g, 73% yield) as a brown oil. MS (m/z) 366.0/368.0 (M+H).

Provenance & Evidence