2-Bromo-5-iodopyrazine → 2-(5-Bromo-pyrazin-2-yl)-4-methyl-thiazole-5-carboxylic acid benzylamide

Participants

Reaction Conditions

Reaction Steps

Part B. An oven-dried sealed tube was charged with 2-bromo-4-methyl-thiazole-5-carboxylic acid benzylamide (400 mg, 1.28 mmol, 1.0 equiv). The sealed tube was purged with nitrogen and Rieke zinc (4 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-bromo-5-iodo-pyrazine (292 mg, 1.0 mmol, 0.8 equiv), Pd(PPh3)4 (59 mg, 0.05 mmol, 4 mol %) in tetrahydrofuran (3 mL). The reaction mixture was purged with nitrogen for 10 min, then stirred at 160° C. for 20 hr. After cooling, the solvent was removed in vacuo and the crude product was purified by preparative HPLC (acetonitrile/water, 0.1% trifluoroacetic acid) to afford 2-(5-bromo-pyrazin-2-yl)-4-methyl-thiazole-5-carboxylic acid benzylamide (35 mg, 7%). 1H NMR (400 MHz, CD2Cl2) δ 9.12 (s, 1H), 8.63 (s, 1H), 7.28-7.36 (m, 5H), 6.22 (bs, 1H), 4.59 (d, J=8.0 Hz, 2H), 2.72 (s, 3H); HRMS (M+H)+=389.01.

Provenance & Evidence