Cesium carbonate → ethyl-2-(1-{2-[(tert.-butoxycarbonyl)-amino]ethyl}-1H-indol-3-yl)-2-oxoacetate

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Reaction Steps

The general procedure 1 was then followed using the above product (6.68 mmol, 1.54 g), ethyl-2-(1H-indol-3-yl)-2-oxoacetate (6.68 mmol, 1.45 g) and Cs2CO3 (9.82 mmol, 3.20 g). The purification was achieved by column chromatography (petro-lether:ethylacetate:diethylamine 5:4:1) to yield ethyl-2-(1-{2-[(tert.-butoxycarbonyl)-amino]ethyl}-1H-indol-3-yl)-2-oxoacetate (4.54 mmol, 68%) as white crystals. Mp=114-115° C. IR {tilde over (ν)} [cm−1]=3357; 2977; 1727; 1686; 1638; 1518. EI-MS (m/z)=360 (7.59%; M+•.). 1H NMR (300 MHz, CDCl3) 8.44 (m; 1H; indole-H); 8.34 (s; 1H; indole-H); 7.42 (m; 1H; indole-H); 7.35 (m; 1H; indole-H); 4.63 (bs; 1H; NH); 4.37 (m; 4H; OCH2CH3; indole-CH2); 3.54 (q; 3J=6.2 Hz; 2H; CH2—N); 1.43 (t; 3H; 3J=7.1 Hz; OCH2CH3); 1.43 (s; 9H; C(CH3)3).

Provenance & Evidence