Potassium Carbonate → HCID 11326663, compound

Participants

Reaction Steps

N-(4-Bromobutyl)phthalimide 7 (9.70 g, 34.40 mmol) was added to a suspension of potassium carbonate (8.20 g, 59.30 mmol) and piperazine-1-carboxylic acid tert-butyl ester 8 (5.00 g, 26.80 mmol) in acetone (125 mL). The mixture was heated at reflux for 14 hours. After cooling to ambient temperature, the reaction mixture was filtered and the filtrate concentrated to a waxy yellow solid. Purification by column chromatography (silica gel, gradient of 70:30 to 0:100 hexanes/ethyl acetate, v/v) gave compound 9 (8.69 g, 84%) as a yellow solid: 1H NMR (300 MHz, CDCl3) δ 1.45 (s, 9H), 1.46-1.59 (m, 2H), 1.63-1.76 (m, 2H), 2.32-2.40 (m, 6H), 3.38-3.44 (m, 4H), 3.71 (t, J=6.9 Hz, 2H), 7.71-7.73 (m, 2H), 7.82-7.84 (m, 2H); ESI MS m/z 388 [C21H29N3O4+H]+.

Provenance & Evidence