Trifluoroacetic acid → 6-pyrimidin-2-yl-6-azaspiro[3,3]heptane TFA salt

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Reaction Conditions

Reaction Steps

A 1 L round-bottom flask was charged with trifluoroacetic acid (153.0 mL) and the mixture cooled to 0-5° C. Tert-butyl 2-pyrimidin-2-yl-2,6-diazaspiro[3,3]heptane-6-carboxylate (51.0 g, 0.19 mol) was added and the reaction mixture was stirred at 0-5° C. until dissolution occurred. Then the reaction mixture warmed to 20-25° C. and stirred for 60 min. The reaction mixture was concentrated, azeotroped with DCM (2×50.0 mL), and diluted with DCM (150.0 mL). This solution was slowly added to a well-stirred solution of MTBE (600.0 mL). The resultant slurry was heated to 35-40° C. to give a free-flowing off-white solid. The slurry was cooled to <15° C. and filtered to afford the title compound. 1H NMR (300 MHz, CD3OD) δ: 8.39 (d, J=5.03 Hz, 2H), 6.77 (t, J=5.03 Hz, 1H), 4.35 (s, 4H), 4.32 (s, 4H); 13C NMR (75 MHz, DMSO-d6) δ: 162.5, 158.2, 111.2, 60.0, 55.3, 36.0; LC/MS: m/z=177 [M]+.

Provenance & Evidence