Benzoyl isothiocyanate → (S)-Methyl 3-(3-benzoylthioureido)-2-(tert-butoxycarbonylamino)propanoate

Participants

Reaction Steps

To an ice cold solution of (S)-methyl 3-amino-2-((tert-butoxycarbonyl)amino)propanoate (see US2007/93414A1, 10.3 g, 47.2 mmol) in anhydrous dichloromethane (170 mL) is slowly added benzoyl isothiocyanate (6.35 mL, 47.2 mmol). The reaction is stirred for 2.5 h while slowly warming to room temp. The solvent is removed in vacuo and the residue is purified by BIOTAGE® Silica gel chromatography on a 300 g Thompson Single Step silica cartridge using a linear gradient from 100% hexanes to 100% EtOAc over 10 column volumes to give 4.7 g (26.1%) of the title compound as a pale yellow solid. LC/MS (Condition A): ret. T=3.48 min, (M+Na) 404.

Provenance & Evidence