Sodium cyanoborohydride → Tert-butyl 2-(1-benzhydrylazetidin-3-yl)hydrazinecarboxylate

Participants

Reaction Steps

The title compound was prepared as described in WO2010079443A1. To a solution of tert-butyl 2-(1-benzhydrylazetidin-3-ylidene)hydrazinecarboxylate (16.9 g, 48.1 mmol) in acetic acid (150 mL), sodium cyanoborohydride (3 g, 48.1 mmol) was added portionwise at 25° C. and stirred at the same temperature for 4 h under a nitrogen atmosphere. The solvent was completely evaporated off. The pH was adjusted to 8 to 10 with 1 M aqueous sodium hydroxide solution. The whole was extracted with dichloromethane (2×500 mL). Organic part was dried over sodium sulfate, filtered and concentrated in vacuum to give the crude tert-butyl 2-(1-benzhydrylazetidin-3-yl)hydrazinecarboxylate (16 g, 94%) as a white solid. This material was used as is for the next reaction. MS (ESI, positive ion) m/z (M+1): 354.4. 1H NMR (400 MHz, DMSO) δ 8.26 (s, 1H), 7.40 (d, J=7.5 Hz, 4H), 7.26 (t, J=7.5 Hz, 4H), 7.16 (t, J=7.2 Hz, 2H), 4.68 (t, J=4.6 Hz, 1H), 4.33 (s, 1H), 3.50 (dd, J=12.5, 6.2 Hz, 1H), 3.16 (t, J=7.0 Hz, 2H), 2.78 (t, J=6.9 Hz, 2H), 1.36 (s, 9H).

Provenance & Evidence