Propanoic acid, 2-bromo-2-methyl-, ethyl ester → HCID 59253182, compound

Participants

Reaction Steps

A solution of 5.41 g (0.02 mmol) of 4-acetylsulfanyl-piperidine-1-carboxylic acid tert-butyl ester in ethanol (50 mL) is degassed with nitrogen over 0.5 h and 2.34 g (0.04 mol) of KOH are added, followed by 8.14 g (0.04 mol) of ethyl α-bromoisobutyrate. The reaction is stirred for 18 h at room temperature under a nitrogen atmosphere. The reaction mixture is concentrated under reduced pressure. The residue is partitioned between DCM (100 mL) and water (100 mL). The organic layer is washed with water (50 mL), brine (250 mL), dried over Na2SO4 and filtered. The filtrate is concentrated under reduced pressure and purified by column chromatography (silica, eluent heptanes, 50% ethyl acetate) to afford 6.05 g of 4-(1-ethoxycarbonyl-1-methyl-ethylsulfanyl)-piperidine-1-carboxylic acid tert-butyl ester as a brown oil. Yield: 87%; ES-MS: m/z 354 [M+Na], 232 [[M+H—C5H9O2]; 1H NMR (500 MHz, CHLOROFORM-d) δ ppm 1.25-1.35 (3H, m), 1.46 (9H, s), 1.48-1.53 (2H, m), 1.55 (6H, s), 1.88 (2H, dd, J=13.31, 3.47 Hz), 2.94-3.04 (3H, m), 3.81-3.92 (2H, m), 4.19 (2H, q, J=7.10 Hz)

Provenance & Evidence