Imidazole → 4-(5-Amino-6-nitro-1,3-dioxo-1,3-dihydro-isoindol-2-yl)-piperidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-amino-6-nitro-isoindole-1,3-dione (2.07 g, 10 mmol), tert-butyl 4-amino-piperidine-1-carboxylate (2.5 g, 12 mmol), imidazole (1.63 g, 24 mmol) in dioxane (100 mL) was sealed in a ChemGlass heavy wall pressure flask. After it was heated at 140° C. for 72 h, the reaction mixture was evaporated to dryness at 95° C. (the bath temperature) under reduced pressure. The chromatography of the residue with CH2Cl2/MeOH/28% aqueous NH4OH (320:10:1) afforded the title compound (2.09 g, 54%). 1H NMR (CDCl3) δ 1.49 (s, 9H), 1.73 (m, 2H), 2.38 (m, 2H), 2.80 (m, 2H), 4.20-4.31 (3H), 7.03 (br s, 2H, NH), 7.34 (s, 1H), 8.61 (s, 1H); ESI-MS m/z 391.5 (MH+).

Provenance & Evidence