Hydrochloric Acid → 2-Methylspiro[3,4-dihydropyrrolo[1,2-a]pyrazine-1,4'-piperidine]-6-carbonitrile dihydrochloride

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Reaction Steps

tert-Butyl 6-cyano-2-methyl-spiro[3,4-dihydropyrrolo[1,2-a]pyrazine-1,4′-piperidine]-1′-carboxylate (280 mg, 0.8474 mmol) was dissolved in a mixture of hydrochloric acid in dioxane (8 mL of 4 M, 32.00 mmol) and dioxane (8 mL). The reaction mixture was allowed to stir for 30 minutes and then evaporated to dryness to yield 2-methylspiro[3,4-dihydropyrrolo[1,2-a]pyrazine-1,4′-piperidine]-6-carbonitrile dihydrochloride (258 mg, 99%) as a white solid. ESI-MS m/z calc. 230.2, found 231.5 (M+1)+; Retention time: 0.50 minutes (3 min run). 1H NMR (400 MHz, D2O) δ 7.10 (d, J=4.2 Hz, 1H), 6.59 (d, J=4.3 Hz, 1H), 4.51 (t, J=6.4 Hz, 2H), 4.02 (t, J=6.3 Hz, 2H), 3.66-3.56 (m, 2H), 3.49-3.36 (m, 2H), 2.95 (s, 3H), 2.69-2.59 (m, 2H), 2.54-2.40 (m, 2H).

Provenance & Evidence