Diethyl Ether → Trp-OBn.TFA

Participants

Reaction Steps

N-Boc-L-tryptophan benzyl ester (0.5 g, 1.27 mmol) was dissolved in a solution of 20% TFA in CH2Cl2. The reaction mixture was stirred under nitrogen at room temperature for 30 min and evaporated to dryness. Trituration of the resulting oil with Et2O provided 7 as a white solid (quantitative yield). mp=143-145° C.; 1H NMR (CD3CN) 9.42 (br s, 1H), 7.51 (d, J=8.0 Hz, 1H), 7.43 (d, J=8.2 Hz, 1H), 7.35 (m, 3H), 7.26 (m, 2H), 7.16 (m, 2H), 7.04 (t, J=7.9 Hz, 1H), 5.15 (d, J=12.3 Hz, 1H), 5.09 (d, J=12.3 Hz, 1H), 4.36 (t, J=6.2 Hz, 1H), 3.44 (d, J=6.2 Hz, 2H) ppm; 13C NMR (CDCl3) 170.1, 137.6, 136.0, 129.5, 129.4, 129.3, 128.1, 126.2, 122.9, 120.3, 119.1, 112.6, 107.5, 68.8, 54.4, 26.9 ppm; IR (KBr) 3412, 2840, 1742, 1673, 1498, 1205, 1137, 735 cm−1; HRMS calcd for C18H19N2O2 294.1368 found 294.1362.

Provenance & Evidence