Sodium Iodide → tert-Butyl piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of 2,3-dihydrobenzo[1,4]dioxine-5-carboxylic acid(piperidin-4-ylmethyl)amide (28.6 g, 104 mmol), 4-(3-chloropropane-1-sulfonyl)piperazine-1-carboxylic acid tert-butyl ester (33.9 g, 104 mmol), sodium iodide (7.8 g, 52 mmol), and triethylamine (29 mL, 209 mmol) in N,N-dimethylformamide (70 mL) was stirred at 90° C. for 4 hours. The cooled reaction mixture was partitioned between ethyl acetate and water. The ethyl acetate layer was washed with water (three times) and brine, dried (Na2SO4) and the solvents evaporated in vacuo. The crude product was purified by silica gel chromatography (5% methanol-dichloromethane) and crystallization from ethyl acetate-hexane to give 4-[3-(4-{[2,3-dihydrobenzo[1,4]dioxin-5-carbonyl)amino]-methyl}piperidin-1-yl)propane-1-sulfonyl]piperazine-1-carboxylic acid tert-butyl ester (37.5 g, 64%); m.p. 130-132° C. Analysis for C27H43N4O7 S: Calcd.: C, 57.12; H, 7.63; N, 9.87. Found: C, 57.01; H, 7.40; N, 9.94.

Provenance & Evidence