(1R,3S)-3-[(tert-butoxycarbonyl)amino]cyclopentyl methanesulfonate → methyl 4-[4-([[(1S,3S)-3-[[(tert-butoxy)carbonyl]amino]cyclopentyl]sulfanyl]methyl)-5-methyl-1,3-oxazol-2-yl]benzoate

Participants

Reaction Steps

To a solution of methyl 4-[5-methyl-4-(sulfanylmethyl)-1,3-oxazol-2-yl]benzoate (920 mg, 3.49 mmol, 1.00 equiv) in N,N-dimethylformamide (20 mL) maintained under an inert atmosphere of nitrogen was added cescium camonate (2.3 g). The mixture was stirred for 20 min then tert-butyl N-[(1S,3R)-3-(methanesulfonyloxy)cyclopentyl]carbamate (1.0 g, 3.58 mmol, 1.02 equiv) was added. The resulting solution was stirred at 35° C. for 50 min then the product was precipitated by the addition of 50 mL water. The precipitate was collected by filtration, washed with water and then dried under vacuum to give 1.37 g (88%) of methyl 4-[4-([[(1S,3S)-3-[[(tert-butoxy)carbonyl]amino]cyclopentyl]sulfanyl]methyl)-5-methyl-1,3-oxazol-2-yl]benzoate as a white solid. LC-MS: (ES, m/z): 447 [M+H]+, 391, 271, 230, 115.

Provenance & Evidence