Hydrochloric Acid → (1S,2S)-1-N-[5-(Trifluoromethyl)pyrazin-2-yl]cyclopentane-1,2-diamine hydrochloride

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Reaction Steps

A solution of 2-chloro-5-(trifluoromethyl)pyrazine (CAS number 799557-87-2; 5.01 g, 27.5 mmol), tert-butyl N-[(1S,2S)-2-aminocyclopentyl]carbamate (CAS number 586961-34-4; 5 g, 24.97 mmol) and DIPEA (13.08 ml, 74.9 mmol) in DMSO (50 ml) was heated in a sealed vial at 120° C. for 2 hours and then 140° C. for 2 hours. The reaction mixture was partitioned between ethyl acetate (400 ml) and water (200 ml). The organics were washed with water (3×100 ml) and brine (100 ml), dried over sodium sulfate and concentrated in vacuo. The resulting residue was purified by column chromatography (silica, 5-40% ethyl acetate/petrol). To the resulting solid was then added HCl in 1,4-dioxane (4M, 30 ml, 120 mmol) and the reaction was stirred at room temperature overnight. The reaction was concentrated in vacuo, triturated with diethyl ether and filtered to afford the title compound.

Provenance & Evidence