反应详情

0.303 g (1.773 mmol) of 2-(chloromethyl)imidazo[1,2-a]pyridine were dissolved in 15 ml of dimethylformamide with magnetic stirring and then 0.253 g (1.773 mmol) of sarcosine methylester hydrochloride and 0.741 ml (5.32 mmol) of triethylamine were added. The mixture was stirred at r.t. for 16 h, and then treated with 30 ml of a saturated NaCl aqueous solution. The aqueous phase was concentrated in vacuo. The residue was triturated in 75 ml of isopropanol, the salts were removed by filtration and the filtrate was concentrated in vacuo. The crude residue was purified by flash chromatography on a silica gel cartridge (eluent: dichloromethane/methanol, 95/5, v/v). 0.107 g (yield=26%) of methyl 2-((imidazo[1,2-a]pyridin-2-ylmethyl)(methyl)amino)acetate were obtained as a pale yellow oil. LC-MS: m/z=234 (MH+); UV purity at 254 nm=99%. 1H NMR (300 MHz, DMSO) δ 8.49 (d, J=6.8 Hz, 1H), 7.79 (s, 1H), 7.47 (d, J=9.0 Hz, 1H), 7.18 (ddd, J=9.0, 6.7, 1.2 Hz, 1H), 6.84 (td, J=6.7, 1.1 Hz, 1H), 3.76 (s, 2H), 3.61 (s, 3H), 2.32 (s, 3H).

1. stirringThe mixture was stirred at r.t. for 16 h
2. concentrationThe aqueous phase was concentrated in vacuo
3. customThe residue was triturated in 75 ml of isopropanol
4. customthe salts were removed by filtration
5. concentrationthe filtrate was concentrated in vacuo
6. customThe crude residue was purified by flash chromatography on a silica gel cartridge (eluent