6-iodohex-1-yne

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

Procedure: To a solution of sodium hydride (60% oil, 2.55 g, 63.6 mol) in DMF (50 ml), trifluoroacetamide (8.99 g, 79.6 mmol) was added portionwise as about 10 portions with ice cooling. Subsequently, a solution of 6-iodo-1-hexyne (3.31 g, 15.9 mmol) in DMF (15 ml) was added to the reaction mixture. The reaction mixture was stirred at room temperature for four hours. The reaction mixture was added with saturated aqueous ammonium chloride (100 ml) and ether (100 ml) for extraction. The ether layer was dried over magnesium sulfate, and concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (eluent; hexane-ethyl acetate mixed solvent) to afford 2.0 g of 6-trifluoroacetamido-1-hexyne (yield; 65.4%). The ether layer was dried over magnesium sulfate concentrated under reduced pressure the resulting residue was purified by silica gel column chromatography (eluent; hexane-ethyl acetate mixed solvent)

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

Procedure: In a flame-baked, two neck 100 mL round bottom flask, 20 mmol of L-alanine methyl ester hydrochloride (2.8 g), 40 mmol of K2CO3 (5.53 g), and 20 mmol of tetrabutylammonium iodide (TBAI, 7.39 g) were charged under a stream of dry N2 gas. 35 mL of tetrahydrofuran (THF) was slowly added and the mixture was stirred for 15 min at room temperature. 2.6 mL of 6-iodo-hex-1-yne was added dropwise while the mixture was stirred. The reaction mixture was refluxed at ˜70° C. for 15-18 h with TLC check. After consumption of the starting material, the mixture was cooled to room temperature, diluted by diethylether, and filtered. The filtrate was further diluted by diethylether and filtered again. The solvent was removed by rotavap and the crude product was purified by flash chromatography on silica gel (1:2=Hexane/EtOAc, 1% triethylamine) to give N-(5-hexynyl) L-alanine methyl ester (2.044 g, 11.2 mmol) as a yellow oil. Yield: 56%. Rf=0.27 (1:1=Hexane/EtOAc); ESI-MS [M+H]+=184.1 m/z; 1H NMR (300 MHz, CDCl3): δ 3.70 (s, 3H), 3.32 (q, J=7.0 Hz, 1H), 2.53 (m, 2H), 2.18 (m, 2H), 1.92 (t, J=2.6 Hz, 1H), 1.56 (m, 5H), 1.27 (d, J=7.0 Hz, 3H); 13C NMR (75 MHz, CDCl3): δ 176.29, 84.21, 68.41, 56.61, 51.74, 47.41, 29.20, 26.01, 19.11, 18.23. was stirred The reaction mixture was refluxed at ˜70° C. for 15-18 h with TLC check After consumption of the starting material the mixture was cooled to room temperature diluted by diethylether filtered The filtrate was further diluted by diethylether filtered again The solvent was removed by rotavap the crude product was purified by flash chromatography on silica gel (1:2=Hexane/EtOAc, 1% triethylamine)

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

Procedure: To a solution of sodium hydride (60% oil, 2.55 g, 63.6 mol) in DMF (50 ml), trifluoroacetamide (8.99 g, 79.6 mmol) was added portionwise as about 10 portions with ice cooling. Subsequently, a solution of 6-iodo-1-hexyne (3.31 g, 15.9 mmol) in DMF (15 ml) was added to the reaction mixture. The reaction mixture was stirred at room temperature for four hours. The reaction mixture was added with saturated aqueous ammonium chloride (100 ml) and ether (100 ml) for extraction. The ether layer was dried over magnesium sulfate, and concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (eluent; hexane-ethyl acetate mixed solvent) to afford 2.0 g of 6-trifluoroacetamido-1-hexyne (yield; 65.4%). Melting point: 41.0-42.5° C. The ether layer was dried over magnesium sulfate concentrated under reduced pressure the resulting residue was purified by silica gel column chromatography (eluent; hexane-ethyl acetate mixed solvent)

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

Procedure: To a solution of sodium hydride (60% oil, 2.55 g, 63.6 mol) in DMF (50 ml), trifluoroacetamide (8.99 g, 79.6 mmol) was added portionwise as about 10 portions with ice cooling. Subsequently, a solution of 6-iodo-1-hexyne (3.31 g, 15.9 mmol) in DMF (15 ml) was added to the reaction mixture. The reaction mixture was stirred at room temperature for four hours. The reaction mixture was added with saturated aqueous ammonium chloride (100 ml) and ether (100 ml) for extraction. The ether layer was dried over magnesium sulfate, and concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (eluent; hexane-ethyl acetate mixed solvent) to afford 2.0 g of 6-trifluoroacetamido-1-hexyne (yield; 65.4%). The ether layer was dried over magnesium sulfate concentrated under reduced pressure the resulting residue was purified by silica gel column chromatography (eluent; hexane-ethyl acetate mixed solvent)