Potassium Hydroxide → tert-butyl (2S)-4-[(4-amino-2-methylphenyl)methyl]-2-methylpiperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

1,1-Dimethylethyl (2S)-4-{[4-(acetylamino)-2-methylphenyl]methyl}-2-methyl-1-piperazinecarboxylate (D53) (497 mg, 1.4 mmol) and KOH (1M aq. soln., 5 ml) were combined in MeOH (5 ml) and heated to 140° C. for 1 h in a microwave reactor. The reaction mixture was diluted with MeOH (5 ml) and heated for a total of 4 h 55 minutes at 130° C. in the microwave. The reaction mixture was concentrated to remove the MeOH and partitioned between DCM and water. The organic layer was dried and concentrated to give the crude product which was purified by column chromatography. Elution with 0-100% diethyl ether/petroleum ether followed by a column flush with 10% (2M NH3 in MeOH) in DCM yielded the title compound as a yellow oil (233 mg). δH (CDCl3, 400 MHz) 6.97 (1H, d), 6.52 (1H, d), 6.46 (1H, dd), 4.17 (1H, br.s), 3.76 (1H, d), 3.57 (2H, br.s), 3.29 (2H, m), 3.01 (1H, td), 2.70 (1H, d), 2.56 (1H, d), 2.30 (3H, s), 2.10 (1H, dd), 1.90 (1H, m), 1.45 (9H, s), 1.18 (3H, d). MS (AP+): 342.3 (MNa+), no molecular (MH+) ion observed.

Provenance & Evidence