3-Bromo-2-methyl-1-propene → 1-tert-Butyl 4-methyl 4-(2-methylallyl)piperidine-1,4-dicarboxylate

Participants

Reaction Steps

A solution of N-Boc-piperidine-4-carboxylic acid methyl ester (2.00 g, 8.22 mmol) in THF (40 mL) was cooled to −78° C. Under nitrogen, a 2.0 M THF solution of LDA (6.17 mL, 12.3 mmol) was added dropwise. The reaction mixture was stirred at −78° C. for 30 minutes before a solution of 3-bromo-2-methylpropene (1.60 g, 11.9 mmol) in THF (2 mL) was added. After the reaction was stirred for 1 hour at this temperature, a sample was taken for LC-MS analysis and it showed that the reaction was completed. The reaction was quenched by adding saturated ammonium chloride solution (5 mL) and the mixture was allowed to warm up to room temperature. The mixture was then extracted with EtOAc (50 mL twice). The combined organic layers were washed with brine (30 mL), dried over anhydrous sodium sulfate and filtered. The filtrates were concentrated and the crude product was purified by column chromatography eluting with 0-30% ethyl acetate/hexane to give the title compound. LC-MS (IE, m/z): 242.21 [M−56+1]+.

Provenance & Evidence