Potassium Carbonate → 3-(2,2-Difluoro-benzo[1,3]dioxol-5-ylmethyl)-piperidine-1-carboxylic acid tert-butyl ester

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Reaction Steps

1-Boc-3-methylene piperidine (842 mg, 4.27 mmol) was degassed (neat) for 15 minutes and then treated with a THF solution of 9-BBN (0.5 M in THF, 8.6 mL, 4.3 mmol). The reaction mixture was refluxed for 2 h, then cooled to rt. The reaction mixture was then added, via cannula, to a preformed solution of 5-bromo-2,2-difluoro-1,3-benzodioxole (1.00 g, 4.22 mmol), Pd(dppf)Cl2—CH2Cl2 (94 mg, 0.128 mmol), and potassium carbonate (746 mg, 5.40 mmol) in DMF/H2O (10 mL/1 mL). The resultant mixture was heated at 60° C. for 18 h, cooled to rt, poured into water, basified to pH 11 with 1 N NaOH, and extracted with EtOAc (3×). The organic layers were combined, dried (Na2SO4), and concentrated. The crude residue was purified (FCC) to give 3-(2,2-difluoro-benzo[1,3]dioxol-5-ylmethyl)-piperidine-1-carboxylic acid tert-butyl ester (1.00 g, 67%).

Provenance & Evidence