BOC-TRP-OBZL

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 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. evaporated to dryness

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In the same manner as Example 5, Boc-Trp-OBzl (1.97 g, 5 mM) was reacted with 4-methoxy-2,3,6-trimethylbenzene-sulfonyl chloride (1.87 g, 7.5 mM) in dichloromethane in the presence of sodium hydroxide (500 mg, 12.5 mM) and cetyltrimethylammonium chloride (16 mg, 0.05 mM). The reaction product was then hydrolyzed with an aqueous solution of sodium hydroxide to give Boc-Trp(Mtr)-OH. Yield 2.05 g (79.4%); m.p. 78°-80° C.; [α]D22 -24.8° (c=0.5, DMF).

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In dichloromethane (10 ml) was dissolved Boc-Trp-OBzl (789 mg, 2 mM), followed by addition of cetyltrimethylammonium chloride (6.4 mg, 0.02 mM) and crushed sodium hydroxide (200 mg, 5 mM). Then, a solution of 2,4-dimethoxybenzenesulfonyl chloride (710 mg, 3 mM) in dichloromethane (3 ml) was added dropwise to the above mixture. The reaction was conducted at room temperature for 30 minutes, after which it was cooled and brought to pH 2 with 1 N--HCl. Following addition of water (10 ml), the solution was shaken and the dichloromethane layer was separated, washed with water and dried over sodium sulfate. The solvent was then distilled off to give Boc-Trp(Dmb)-OBzl. This product was dissolved in ethanol (10 ml), and under ice-cooling, a 1--N aqueous solution of sodium hydroxide (2.2 ml) was added. The reaction was continued at room temperature for one hour. The ethanol was distilled off and the residual aqueous solution was diluted with water (20 ml) and extracted with ether (20 ml). The water layer was cooled and brought to pH 3 with 10% aqueous citric acid. The solution was then extracted with ethyl acetate and the ethyl acetate layer was washed with water and dried over sodium sulfate. The solvent was then distilled off and the residue was treated with petroleum ether to give Boc-Trp(Dmb)-OH as a solid product. Yield 737 mg; (73%); m.p. 100° C. (decomp.); [α]D22 -9.43° (c=0.5, DMF). after which it was cooled the dichloromethane layer was separated washed with water dried over sodium sulfate The solvent was then distilled off

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of Boc-L-Trp-OBzl (5.00 g), tetra-n-butylammonium sulfate (43 mg) and NaOH (sodium hydroxide) (1.27 g) in methylene chloride (100 ml) was added a solution of ethyl bromoacetate (5.29 g) in methylene chloride (50 ml) in an ice-bath cooling. After being stirred at room temperature for 2 days, the mixture was washed with 5% aqueous potassium hydrogen sulfate solution, 1M aqueous sodium bicarbonate solution and brine, dried over magnesium sulfate, and concentrated in vacuo to afford Boc-L-Trp(CH2COOEt)-OBzl (6.10 g) as an oil. cooling the mixture was washed with 5% aqueous potassium hydrogen sulfate solution, 1M aqueous sodium bicarbonate solution and brine dried over magnesium sulfate concentrated in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 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. evaporated to dryness