N-bromobutanimide → methyl 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)-5-ethyl-2-thiophenecarboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of methyl 5-ethyl-4-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (600 mg, 2.40 mmol) [prepared according to Example 98] in Tetrahydrofuran (THF) (10 ml) was added N-bromosuccinimide (512 mg, 2.88 mmol). The mixture stirred in a sealed tube at 70° C. for 2 h. The reaction mixture was then concentrated and purified with silica gel using a 0-5% gradient (ethyl acetate/hexane) to afford the title compound as an off-white solid: LC-MS (ES) m/z 330 (M+H)+.

Provenance & Evidence