Diisopropylethylamine → [(2S)-2-isocyanato-2-phenylethyl]dimethylamine hydrochloride

Participants

Reaction Conditions

Reaction Steps

To a cooled (0° C.) and stirred solution of triphosgene (27.1 g, 91.32 mmol) in DCM (250 mL) was drop wise added a solution of diisopropylethyl amine (23.6 g, 182.26 mmol) in DCM (50 mL) over a period of 20 min. A solution of N-[(2S)-2-amino-2-phenylethyl]-N,N-dimethylamine (54e, 15.0 g, 91.32 mmol) in DCM (100 mL) was drop wise added to the brown reaction mixture while maintaining the temperature below 10° C. The resulting reaction mixture was removed from cooling and stirred for 2 h at room temperature. The reaction mixture was concentrated under vacuum to a residue and stirred with 10% DCM in hexane (50 mL). The solid N-[(2S)-2-isocyanato-2-phenylethyl]-N,N-dimethylamine hydrochloride compound 54f was separated by filtration and used for the next reaction without further purification. (Note: The obtained solid product was stored under nitrogen). 1H NMR (300 MHz, dmso-d6): δ 3.29 (s, 3H), 3.38 (s, 3H), 3.68 (t, J=10.1 Hz, 1H), 4.42 (dd, J=11.5, 6.5 Hz, 1H), 5.35 (dd, J=9.6, 6.2 Hz, 1H), 7.4-7.6 (m, 5H).

Provenance & Evidence