Hydrochloric Acid → 2-Methyl-6,7-bis(trifluoromethyl)spiro[3,4-dihydropyrrolo[1,2-a]pyrazine-1,4'-piperidine]

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Reaction Steps

tert-Butyl 2-methyl-6,7-bis(trifluoromethyl)spiro[3,4-dihydropyrrolo[1,2-a]pyrazine-1,4′-piperidine]-1′-carboxylate (from step 1) was taken up in CH2Cl2 (2 mL) and HCl (1.7 mL of 4 M, 6.8 mmol) was added. The mixture was allowed to stir for 30 min before it was concentrated under reduced pressure. The residue was taken up in ethyl acetate and was washed with sat. aq. NaHCO3, then brine. The organic layer was dried over sodium sulfate, filtered and concentrated to give 2-methyl-6,7-bis(trifluoromethyl)spiro[3,4-dihydropyrrolo[1,2-a]pyrazine-1,4′-piperidine] (22 mg, 2% over 2 steps). ESI-MS m/z calc. 341.1, found 342.3 (M+1)+; Retention time: 1.29 minutes.

Provenance & Evidence