1,4-Dioxane → HCID 90960549, compound

Participants

Reaction Steps

To a solution of diamine 2-7 (12.5 g, 25.8 mmol) and DIPEA (13.5 mL, 77.5 mmol) in CH2Cl2 (750 mL) at 0° C. was added p-NO2PhOCOCl (5.47 g, 27.1 mmol) in 4 portions. The resulting mixture was warmed to room temperature and 1,4-dioxane (750 mL) was added and refluxed for 6 h. After cooling, the solution was washed with 10% K2CO3 (3×400 mL) then brine. The organic layer was dried (Na2SO4), filtered, concentrated in vacuo, and purified by flash chromatography (silica, 50% EtOAc/hexanes) affording 9.0 g of cyclic urea 2-8.

Provenance & Evidence