N-bromobutanimide → 2-methoxyethyl 4-(7-(bis((2-(trimethylsilyl)ethoxy)methyl)amino)-6-bromo-3-(1-phenyl-1H-pyrazol-4-yl)pyrazolo[1,5-a]pyrimidin-5-yl)-1-(2-methoxyethoxy)cyclohexanecarboxylate

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Reaction Steps

To a solution of 2-methoxyethyl 4-(7-(bis((2-(trimethylsilyl)ethoxy)methyl)amino)-3-(1-phenyl-1H-pyrazol-4-yl)pyrazolo[1,5-a]pyrimidin-5-yl)-1-(2-methoxyethoxy)cyclohexanecarboxylate (2.28 g, 2.87 mmol) in CH3CN (50 mL) was added NBS (511 mg, 2.87 mmol) and stirred at room temperature for 30 min. Both TLC and LCMS showed complete conversion. All the volatiles were removed under reduced pressure and the residue was purified by a SiO2 column (0-30%, EtOAc/Hexanes, Rf=0.65 in 50% EtOAc) to afford 2-methoxyethyl 4-(7-(bis((2-(trimethylsilyl)ethoxy)methyl)amino)-6-bromo-3-(1-phenyl-1H-pyrazol-4-yl)pyrazolo[1,5-a]pyrimidin-5-yl)-1-(2-methoxyethoxy)cyclohexanecarboxylate as a yellow oil (2.50 g, 99%).

Provenance & Evidence