Dimethylformamide → 3-(3-Bromo-5-iodo-2-thienyl)-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-1,2,4-triazole

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Reaction Steps

Into a solution of 3-(3-bromo-5-iodo-2-thienyl)-4H-1,2,4-triazole (500.0 mg, 1.40 mmol), N,N-dimethylaminopyridine (17.2 mg, 0.140 mmol) and N,N-diisopropylethylamine (0.32 mL, 1.83 mmol) in N,N-dimethylformamide (17.0 mL, 220 mmol) was added [β-(Trimethylsilyl)ethoxy]methyl chloride (0.270 mL, 1.55 mmol) was added and the solution was stirred for 2 h at rt. Water (5.0 mL) and EtOAc (5 mL) were added, the organic layer was separated, washed with brine, dried over MgSO4, filtered, concentrated and the obtained residue was purified by column chromatography (SiO2, elution with 0-30% EtOAc in hexane) to give the title compound as a yellowish oil (653 mg, (87% major isomer, 13% minor isomer) LCMS: (FA) ES+, 486, 488. (major isomer)1H NMR (400 MHz, d6-DMSO) δ: 8.81 (s, 1H), 7.45 (s, 1H), 5.540-5.545 (s, br, 2H), 3.62-3.66 (m, 2H), 0.840-0.880 (m, 2H), −0.05 (s, 9H). LCMS: (FA) ES+, 486, 488. (minor isomer) 1H NMR (400 MHz, d6-DMSO) δ: 8.215 (s, 1H), 7.615 (s, 1H), 5.48 (s, br, 2H), 3.44-3.50 (m, 2H), 0.75-0.80 (m, 2H), −0.08 (s, 9H).

Provenance & Evidence