反应详情

温度

70 °C

A solution of methyl 5-methyl-4-(1-methyl-1H-pyrazol-5-yl)-2-furancarboxylate (600 mg, 2.72 mmol) [prepared in Example 116] and n-bromosuccinimide (485 mg, 2.72 mmol) in tetrahydrofuran (13.6 ml) was stirred in a sealed tube for 1 h at 70° C. The reaction mixture was divided and half of the solution was treated with 6N sodium hydroxide (4.54 ml, 27.2 mmol) which stirred at 70° C. in a sealed tube for 4 h. The solution was partitioned between H2O-DCM and the pH of the aqueous phase was adjusted to ˜4 and washed several times with DCM. The combined organic fractions were dried over Na2SO4, concentrated and used directly affording 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)-5-methyl-2-furancarboxylic acid (369 mg, 1.29 mmol, 48% yield) as an orange oil: LCMS (ES) m/e 285, 287 (M, M+2)+.

1. customThe solution was partitioned between H2O-DCM
2. washwashed several times with DCM
3. dry with materialThe combined organic fractions were dried over Na2SO4
4. concentrationconcentrated