4-Methylmorpholine → (2R)-2-(tert-Butoxycarbonylamino)-3-(4-methylbenzylthio)propionic acid methylamide

Participants

Reaction Steps

A solution of N-methylmorpholine (0.217 ml) and isobutyl chloroformate (0.256 ml) in tetrahydrofuran (5 ml) is added to a solution of (2R)-2-(tert-butoxycarbonylamino)-3-(4-methylbenzylthio)propionic acid (reference compound No. 3-1, 700 mg) in tetrahydrofuran (15 ml) under a nitrogen atmosphere and freezing medium (ice-sodium chloride) cooling, and the mixture is stirred for 15 minutes. Then, a 40% aqueous N-methylamlne solution (0.756 ml) is added thereto under a freezing medium (ice-sodium chloride) cooling, and the mixture is further stirred for two hours. A 5% aqueous sodium hydrogencarbonate solution is added to the system of reaction, and the whole is extracted with ethyl acetate. The organic layer is washed with a saturated sodium chloride solution, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The obtained residue is purified by silica gel column chromatography to give the titled compound.

Provenance & Evidence