Acetonitrile → (2R,5R)-4-Benzyloxycarbonylmethyl-5-methoxymethyl-2-methyl-piperazine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a stirred suspension of (2R,5R)-5-methoxymethyl-2-methyl-piperazine-1-carboxylic acid tert-butyl ester (11 g, 45 mmol), potassium carbonate (6.79 g, 49.14 mmol) and acetonitrile (48 mL) was added benzyl bromoacetate (7.08 mL, 44.67 mmol) dropwise at ambient temperature. The reaction was stirred for 18 h at ambient temperature, then diluted with chloroform (150 mL), filtered and the filtrate concentrated. The crude oil was purified by column chromatography on silica gel (gradient elution, 0-70%, EtOAc/petrol), to give the title compound (16 g, 92%) as a pale yellow oil. 1H NMR (Me-d3-OD): 7.45-7.22 (5H, m), 5.21-5.12 (2H, m), 4.84 (2H, s), 4.16-4.03 (1H, m), 3.91 (1H, d), 3.62 (1H, d), 3.56-3.40 (2H, m), 3.31-3.19 (3H, m), 3.04-2.92 (1H, m), 2.80 (1H, dd), 2.68 (1H, dd), 1.48 (9H, s), 1.19 (3H, d).

Provenance & Evidence