Methanol → 1-Boc-4-(4-methoxycarbonylphenyl)piperazine

Participants

Reaction Conditions

Reaction Steps

A mixture of 1-(tert-butoxycarbonyl)-4-(4-trifluoromethanesulfonyloxyphenyl)piperazine (1.92 g, 4.68 mmol), palladium (II) acetate (52.5 mg, 0.23 mmol), 1,1'-bis(diphenylphosphino)ferrocene (325.0 mg, 0.59 mmol), triethylamine (1.3 ml, 9.33 mmol), methanol (8 ml) and dimethylformamide (20 ml) was purged with carbon monoxide for 15 minutes, sealed under a balloon of carbon monoxide and stirred at 60° C. overnight (18 hours). The reaction mixture was allowed to cool, concentrated in vacuo to a small volume and the residue triturated with ethyl acetate. The solid was collected, washed with ethyl acetate and dried to give the title compound (0.659 g, 44%), as a pale cream solid. Evaporation of the ethyl acetate mother liquors and purification of the residue by flash chromatography (eluting with 5% to 10% ethyl acetate in dichloromethane) gave more of the title compound (0.492 g, 33%); δH (CDCl3) 1.49 (9H, s, C(CH3)3), 3.31 (4H, m, 2×piperazinyl CH2), 3.60 (4H, m, 2×piperazinyl CH2), 3.87 (3H, s, CO2CH3), 6.89 (2H, m, ArH), and 7.94 (2H, m, ArH).

Provenance & Evidence