Ethyl Acetate → 3(S)-(6-chloro-9H-beta-carbolin-8-ylcarbamoyl)-morpholine-4-carboxylic acid tert-butyl ester

Beteiligte Stoffe

Reaktionsschritte

A solution of morpholine-3(S),4-dicarboxylic acid 4-tert-butyl ester (2.83 g, 12.7 mmol) in pyridine (106 ml) was stirred at RT. 6-chloro-9H-β-carbolin-8-ylamine (2.30 g, 10.6 mmol) was added, followed by EDCI (4.06 g, 21.2 mmol). The clear orange-to-brown solution was stirred at RT for 14 hr. The solution was diluted with H2O (120 ml) and poured into a separatory funnel containing EtOAc (200 ml), H2O (100 ml) and brine (100 ml). The mixture was shaken and the layers were separated. The aqueous layer was extracted with EtOAc (2×50 ml) and the combined organic layers were washed with brine. The organic layer was dried, filtered and concentrated to a reduced volume, then added drop-wise to a stirring solution of 1:1 Et2O/hexanes (500 ml). The precipitate which formed was filtered and washed with 1:1 Et2O/Hexanes. The filtrate was concentrated to a reduced volume and a second crop of precipitate was collected. The solid product was placed under high vacuum for 2 hr to yield 3(S)-(6-chloro-9H-β-carbolin-8-ylcarbamoyl)-morpholine-4-carboxylic acid tert-butyl ester as a pale yellow to pale brown solid (4.36 g).

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