p-Toluenesulfonic acid → (S)-cyclopentyl 2-amino-4-methylpentanoate

Participants

Reaction Steps

TsOH salt (7.98 g, 21.51 mmol) was dissolved in THF (40 ml) and triethylamine (6 ml, 21.5 mmol) added. 4-Nitrobenzoyl chloride (4 g, 21.5 mmol) was added portionwise with cooling, ice bath. The reaction was stirred at room temperature for 16 h before evaporation to dryness. The residue was dissolved in DCM (100 ml) and washed with saturated sodium hydrogen carbonate (3×100 ml), 1 M HCl (3×100 ml) and brine, dried (Na2SO4), and the solvent removed in vacuo. to give the required product 5.25 g (70% yield) which was used in the next step without further purification, LCMS purity 100%, m/z 349 [M++H]+

Provenance & Evidence