Ethyl bromoacetate → (9-Cyano-9H-xanthen-9-yl)-acetic acid ethyl ester

Beteiligte Stoffe

Reaktionsschritte

9H-Xanthene-9-carbonitrile [27] (1.0 g, 4.825 mmol) was dissolved in anhydrous Et2O and cooled in an icebath. n-Butyl lithium (1.93 mL, 6.75 mmol. 2.5M soln. in hexanes) was added dropwise over 10 min. with continuos stirring. Stirring was continued for 30 min. at the same temperature and then brought to room temperature. The reaction mixture was heated at reflux (1 hr), cooled in an icebath and ethyl bromo acetate (0.75 mL, 6.755 mmol) was added dropwise via syringe. The resulting mixture was heated at reflux (4 h) cooled and filtered. The residue was washed with ether (25 mL). Water (25 mL) was added to the filterate and the organic layer was separated. The aqueous layer was once again extracted with ether (25 mL). The combined ether extracts were washed with water and brine, dried (MgSO4) and evaporated under reduced pressure to give an oil which was purified by mplc using pet. ether: EtOAc (9:1) as eluent to give 0.9 g (64%) of the product as a colorless oil. 1H NMR (CDCl3)d: 1.04-1.08 (t, J=7.5 Hz, CH3), 3.01 (s, 2H, CH2), 3.90-3.99 (q, 2H, CH2), 7.14-7.69 (m, 8H, Ar—H). 13C NMR (CDCl3)d: 13.54, 39.06, 48.47, 60.85, 116.88, 118.90, 119.75, 123.81, 127.34, 129.83, 150.30, 166.98.

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