2,2,2-Trifluoroethylamine hydrochloride → HCID 18519913, compound

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Reaction Steps

A few drops of dilute hydrochloric acid were added to a solution of 2,5-dimethoxytetrahydrofuran (16.5 g) in water (70 ml). After stirring at room temperature for 30 minutes 2,2,2-trifluoroethylamine hydrochloride (16.9 g), 1,3-acetonedicarboxylic acid (18.3 g) and sodium acetate (10.0 g) were added and the mixture stirred at room temperature for 2 days. The mixture was diluted to 500 ml with water, saturated with potassium carbonate and extracted with ethyl acetate (×2). The combined organic extracts were washed with aqueous potassium carbonate, dried (MgSO4) and evaporated under reduced pressure. Distillation (90° C.; 0.1 mmHg) gave 8-(2,2,2-trifluoroethyl)-8-azabicyclo[3.2. 1]octan-3-one (8.7 g). Potassium t-butoxide (5.4 g) was added slowly with cooling to a stirred solution of 8-(2,2,2-trifluoroethyl)-8-azabicyclo[3.2.1]octan-3-one (4.0 g) and tosylmethyl isocyanide (4.9 g) in dimethoxyethane (80 ml) and ethanol (5 ml) under nitrogen at such a rate so as to keep the temperature below 10° C. The mixture was stirred for 18 hours while allowing it to warm to room temperature, evaporated under reduced pressure and added to aqueous potassium carbonate solution. The mixture was extracted with ethyl acetate (×2) and the combined extracts were dried (MgSO4) and evaporated under reduced pressure to give an oil. The mixture was extracted with refluxing hexane and the extracts allowed to cool and evaporated under reduced pressure to give exo-3-cyano-8-(2,2,2-trifluoroethyl)-8-azabicyclo[3.2.1 ]octane (2.5 g) m.p. 90-92° C.

Provenance & Evidence