[C:1]1([C:7]#[C:8][C:9]2[N:13]3[CH:14]=[CH:15][CH:16]=[CH:17][C:12]3=[N:11][C:10]=2[CH2:18][OH:19])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[H-].[Na+].[CH2:22]([N:24]([CH2:28][CH3:29])[C:25](Cl)=[O:26])[CH3:23]>CN(C)C=O>[CH2:22]([N:24]([CH2:28][CH3:29])[C:25](=[O:26])[O:19][CH2:18][C:10]1[N:11]=[C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][N:13]2[C:9]=1[C:8]#[C:7][C:1]1[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1)[CH3:23]0.1 g (0.403 mmol) of (3-(phenylethynyl)imidazo[1,2-a]pyridin-2-yl) methanol were solubilised in 3 ml of dimethylformamide with magnetic stirring. The mixture was cooled to 0° C., 0.048 g (1.208 mmol) of sodium hydride (60% by mass) were added portion wise. The mixture was stirred for 10 min at 0° C. and then 0.204 ml (1.611 mmol) of diethylcarbamoyl chloride were added. The cold bath was withdrawn, the mixture was stirred at r.t. for 2 h before being treated with 30 ml of a saturated NaCl aqueous solution. The aqueous phase was extracted with 3×10 ml of ethyl acetate. The combined organic phases were dried on Na2SO4 which was then removed by filtration. The crude residue was purified by flash chromatography on a silica gel cartridge (eluent: heptane/ethyl acetate, 6/4, v/v). 0.101 g (yield=72%) of (3-(phenylethynyl)imidazo[1,2-a]pyridin-2-yl)methyl diethylcarbamate were obtained as a pale yellow solid. LC-MS: m/z=348 (MH+); UV purity at 254 nm=99%. 1H NMR (300 MHz, DMSO) δ 8.61 (d, J=6.8 Hz, 1H), 7.74-7.59 (m, 3H), 7.53-7.38 (m, 4H), 7.13 (td, J=6.8, 1.1 Hz, 1H), 5.30 (s, 2H), 3.22 (q, J=7.1 Hz, 4H), 1.01 (t, J=7.1 Hz, 6H).
Loading…
