反应详情

3-(4-Oxo-4,5,6,7-tetrahydro-1H-indol-3-yl)-propionic acid (2.07 g, 10 mmol), prepared as described in Example 1 above, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide-hydrochloide (2.3 g, 12 mmol), anhydrous 1-hydroxybenzotriazole (1.62 g, 12 mmol) and N,N-diisopropylethylamine (1.75 ml, 10 mmol) were mixed together in 50 ml of dichloromethane and stirred for one hour at room temperature. Tert-butyl 1-piperazinecarboxylate (2.24 g, 12 mmol) was added to the mixture and stirred at room temperature overnight. The reaction mixture was concentrated and the syrup was dissolved in dichloromethane then purified by flash chromatography, eluting with dichloromethane followed by (dichloromethane: methanol 50/1, 30/1) to give 4-[3-(4-oxo-4,5,6,7-tetrahydro-1H-indol-3-yl)-propionyl]-piperazine-1-carboxylic acid tert-butyl ester (4.45 g, 86% pure).

1. stirringstirred at room temperature overnight
2. concentrationThe reaction mixture was concentrated
3. dissolutionthe syrup was dissolved in dichloromethane
4. customthen purified by flash chromatography
5. washeluting with dichloromethane