N-bromobutanimide → Methyl 2-(5-bromothiophen-2-yl)acetate

関与物質

反応手順

Referring once again to FIG. 3, a solution of methyl 2-(thiophen-2-yl)acetate (27.44 g, 175.7 mmol) was dissolved in DMF (500 mL) and stirred in the dark as NBS (37.52 g, 210.8 mmol) was added portion wise. The reaction was stirred for three hours at which TLC indicated completion of the reaction. The reaction was diluted with ether and the organic phase was washed with ammonium chloride and water, then dried with magnesium sulfate and concentrated by rotovap. The resulting crude oil was purified by triturating with hexanes, decanting off the organic phase above the oil, then subjecting the oil to chromatography on a gradient plug of silica gel (hexanes to 10% EtOAc in hexanes) to yield the product as a yellow oil (33.90 g, 144.2 mmol, 82%). The product matches literature data. Kranich, R., et al., “Rational Design of Novel, Potent Small Molecule Pan-Selectin Antagonists,”J. Med. Chem. 50:1101-1115 (2007). 1H NMR (CDCl3) δ: 6.89 (d, J=4.0 Hz, 1H), 6.69 (dt, J=4.0 Hz, 1H), 3.76 (s, 2H), 3.72 (s, 3H).

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