2,6-Diiodopyrazine → 2-(6-Iodo-pyrazin-2-yl)-4-methyl-thiazole-5-carboxylic acid 4-fluoro benzylamide

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Part B. An oven-dried sealed tube was charged with 2-bromo-4-methyl-thiazole-5-carboxylic acid 4-fluoro-benzylamide (1.0 g, 3.03 mmol, 1.0 equiv). The sealed tube was purged with nitrogen and Rieke zinc (10 mL, 10 g of zinc in 100 mL of tetrahydrofuran) was added. The reaction was heated in the microwave oven for 15 min at 100° C. Stirring was stopped and the remaining zinc was allowed to settle. The supernatant containing the zinc reagent was transferred via syringe to a solution of 2,6-diiodopyrazine (704 mg, 2.1 mmol, 0.7 equiv), Pd(PPh3)4 (175 mg, 0.2 mmol, 5 mol %) in tetrahydrofuran (2 mL) and dimethyl formamide (0.1 mL). The reaction mixture was purged with nitrogen for 10 min, then stirred at 140° C. for 20 hr. After cooling, the solvent was removed in vacuo and the crude product was purified by column chromatography [SiO2, ethyl acetate/heptane, 10:90 to 40:60, v/v] to afford 2-(6-iodo-pyrazin-2-yl)-4-methyl-thiazole-5-carboxylic acid 4-fluoro-benzylamide (100 mg, 7%). MS (M+H)+=455.1, Rt=1.53 min.

Herkunft & Nachweise