反应详情

A solution of methyl 5-ethyl-4-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (980 mg, 3.92 mmol) [prepared in Example 98] and N-bromosuccinimide (697 mg, 3.92 mmol) in tetrahydrofuran (19.6 ml) was stirred in a sealed tube for 1 h at 70° C. The reaction mixture was then partitioned between H2O-DCM and the aqueous phase was washed several times with DCM. The combined organic fractions were dried over Na2SO4, concentrated then purified via column chromatography (silica, 10-40% EtOAC in hexanes) yielding methyl 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)-5-ethyl-2-thiophenecarboxylate (1.1 g, 3.34 mmol, 85% yield) as a yellow oil: LCMS (ES) m/e 329, 331 (M, M+2)+.

1. customThe reaction mixture was then partitioned between H2O-DCM
2. washthe aqueous phase was washed several times with DCM
3. dry with materialThe combined organic fractions were dried over Na2SO4
4. concentrationconcentrated
5. customthen purified via column chromatography (silica, 10-40% EtOAC in hexanes)