1-Bromooctane → N-Iodopropargyloxycarbonyl glycine n-octyl ester

Participants

Reaction Steps

N-Iodopropargyloxycarbonyl glycine (compound 1, 6.50 g., 22.97 mmole) was dissolved in anhydrous acetonitrile (100 ml.), treated with 1,8-diazabicyclo[5.4.0]undec-7-ene (3.5 ml., 23.40 mmole) and stirred at room temperature for 5 minutes. n-Octylbromide (4.00 ml., 23.16 mmole) was added and the reaction mixture was stirred at room temperature for 17 hours, then heated at reflux temperature for 6 hours. The reaction mixture was concentrated under reduced pressure and the resultant residue was dissolved in ethyl acetate. The ethyl acetate solution was washed with water, 5% aqueous citric acid, saturated aqueous sodium bicarbonate, saturated aqueous sodium chloride, dried over magnesium chloride, filtered and concentrated under reduced pressure. The resultant residue was purified utilizing column chromatography (silica gel, 200 g.) and eluted with ethyl acetate/hexane (1:10) to afford N-Iodopropargyloxycarbonyl glycine n-octyl ester (Compound 3) as a clear colorless liquid which crystallized on standing. m.p. 43°-46° C. Elemental Analysis: C14H22NO4 l: Calc'd. C: 42.55, H: 5.61, N: 3.54. Found: C: 43.73, H: 5.62, N: 3.54. (Ethyl acetate was present in 0.5 mole %). 1H-NMR (200 MHz, CDCl3) δppm =0.89, m, 3H (--CH3), 1.30, m, 10H (--(CH2)5 --CH3), 1.64, m, 2H (--CH2 --), 4.0,d, J=3.4 Hz., 2H (--N--CH2 --), 4.1-4.2, m, 2H (--CH2 --), 4.86, s, 2H (C--CH2 --O), 5.32, m, 1H (--NH--). IR (neat) 3460, 2920, 2850, 2200, 1740, 1560, 1480, 1400, 1360, 1200, 1060, 980 cm-1.

Provenance & Evidence