Triethylamine → (S)-tert-Butyl 4-(4-(methoxycarbonyl)piperidin-1-yl)azepane-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

Methyl cyclopent-3-ene-1-carboxylate (4.42 g, 35 mmol) was dissolved in DCM/MeOH (160 mL, 3:1) and cooled to −78° C. Ozone was passed through the solution until a blue colour persisted. Excess ozone was purged from the reaction mixture with dry N2. Dimethylsulfide (10 mL) was added and the reaction mixture was warmed to rt, the solvent was removed in vacuo. The residue was added to a solution of tert-butyl (4S)-4-aminoazepane-1-carboxylate (7.5 g, 35 mmol), STAB (18.57 g, 87.6 mmol), NEt3 (4.26 g, 42.1 mmol) and acetic acid (1.8 mL) in DCE (200 mL). The mixture was stirred for 3 hours at rt and was then poured into aqueous Na2CO3 solution. The mixture was extracted with EtOAc (3×200 mL), the organic phase were washed with water (100 mL) and brine (100 mL), dried over Na2SO4. The solvent was removed in vacuo, and the residue was purified by column chromatography (gradient 0% to 25% EtOAc in Petroleum ether) to give tert-butyl (4S)-4-[4-(methoxycarbonyl)piperidin-1-yl]azepane-1-carboxylate (7.7 g, 64.6% yield) as a yellow oil.

Provenance & Evidence