2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → N-Carboxy-[1-butyl-4-piperidinylmethyl]-carbazole
Reaction equation
[C:1]([N:4]1[CH:16]2[CH:11]([CH2:12][CH2:13][CH2:14][CH:15]2[CH2:17][CH:18]2[CH2:23][CH2:22][N:21]([CH2:24][CH2:25][CH2:26][CH3:27])[CH2:20][CH2:19]2)[C:10]2[C:5]1=[CH:6][CH:7]=[CH:8][CH:9]=2)([OH:3])=[O:2].ClC1C(=O)C(C#N)=C(C#N)C(=O)C=1Cl>C(Cl)(Cl)Cl>[C:1]([N:4]1[C:16]2[C:15]([CH2:17][CH:18]3[CH2:23][CH2:22][N:21]([CH2:24][CH2:25][CH2:26][CH3:27])[CH2:20][CH2:19]3)=[CH:14][CH:13]=[CH:12][C:11]=2[C:10]2[C:5]1=[CH:6][CH:7]=[CH:8][CH:9]=2)([OH:3])=[O:2]Participants
4
Procedure
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).