Nitrogen → HCID 86657019, compound

Participants

Reaction Steps

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.

Provenance & Evidence