2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → N-Carboxy-[1-butyl-4-piperidinylmethyl]-carbazole

Participants

Reaction Steps

N-Carboxy-[1-butylpiperidin-4-ylmethyl]-1,2,3,4,4a,9a-hexahydrocarbazole (0.530 g, 1.32 mmol) was dissolved in chloroform (25 ml) and treated with 2,3-dichloro-5,6-dicyano-1, 4-benzoquinone (0.329 g, 1.58 mmol) with stirring. The mixture was heated to reflux for 12 hours, cooled, and more 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (0.329 g 1.58 mmol) added with stirring. The mixture was heated to reflux for 12 hours, cooled and evaporated under reduced pressure. The residue was purified by Silica-gel chromatography, eluting with 2%MeOH/CHCl3 to give the title compounds as 3:1 mixture. The mixture was separated by preparative HPLC using a Waters Micro Bondapak C18 (300 mm×7.8 mm) column and eluting with 75:25 MeCN: 0.1M Ammonium Acetate (pH 5.0).

Provenance & Evidence