Aluminium lithium hydride → 1-(3,3-difluorocyclobutyl)-N,N-dimethylmethanamine

Participants

Reaction Steps

A solution of 3,3-difluoro-N,N-dimethylcyclobutanecarboxamide (24 g, 147 mmol) prepared in Part A in THF (500 mL) was added to a stirred suspension of lithium aluminum hydride (7.5 g, 198 mmol) in 500 mL THF at 0° C. The mixture was allowed to come to RT. After stirring the reaction mixture at RT for 18 h, it was quenched by slowly adding 10 mL 6 N NaOH and 5 mL water at 5° C. with stirring. The mixture was stirred at RT for 0.5 h, dried over Na2SO4 and filtered. The filtrate was concentrated to ca. 30 mL by a careful distillation of most of the THF using a Vigreux column. The remaining material was distilled under slightly reduced pressure (ca. 100-200 mm Hg); the fraction (20 mL, by 70-90° C.) contained the title compound contaminated with THF. The residual THF was carefully purged with a gentle stream of nitrogen to yield 1-(3,3-difluorocyclobutyl)-N,N-dimethylmethanamine (12 g, 80 mmol, 54.7% yield). 1H NMR (400 MHz, CDCl3) δ ppm 2.46-2.94 (2H, m), 2.38 (2H, d, J=6.55 Hz), 2.16-2.28 (9H, m).

Provenance & Evidence