3,4-Dichlorophenol → N-(tert-butoxycarbonyl)piperidine

Participants

Reaction Conditions

Reaction Steps

To a stirred solution N-BOC-4-hydroxypiperidine(2.0 g, 0.01 mol), triphenylphosphine (3.68 g, 0.014 mol) and 3,4-dichlorophenol (1.96 g, 0.012 mol) in dry toluene (75 ml) [with molecular sieves, at 0° C. and under Argon] was added diethyl azodicarboxylate (2.52 ml, 0.016 mol), dropwise. The mixture was stirred for 1.5 hrs at 0° C. Filtered the solution and removed the toluene before vigorously stirring in isohexane (100 ml) and filtered the resulting suspension. The filtrate was washed with 2M aqueous NaOH (×8), dried with Na2SO4 and evaporated in vacuo. Purification of the residue on silica (eluant: 20% EtOAc/isohexane) afforded N-Boc-Piperidine, 4-(3,4-dichloropkenoxy)-(9Cl) as a yellow solid (1.96 g). 1H NMR (DMSO): 7.52 (d, 1H), 7.31 (d, 1H), 7.01 (dd, 1H), 4.62 (m, 1H), 3.65 (m, 2H), 3.15 (m, 2H), 1.88 (m, 2H), 1.53 (m, 2H), 1.40 (s, 9H), MS (ES+): 346.3 (MH+), 368.4 (MNa+).

Provenance & Evidence