反应详情

To a stirred solution of methyl 3-chloro-1H-pyrrole-2-carboxylate (1.00 g, 6.30 mmol) in DMF (15 mL) was added NaH (0.45 g, 18.80 mmol, 99%, dry) and the contents were stirred for 1 h at ambient temperature. NH2Cl (42.0 mL, 0.327 g, 6.30 mmol) was added at −10° C. to the reaction mixture and the contents were stirred for another 30 min at −10° C. The solvents were removed under reduced pressure and the residue was extracted with MTBE. The MTBE layer was passed through anhydrous Na2SO4 and concentrated under reduced pressure to give a brown solid. The crude residue was purified by CombiFlash (REDISEP®, silica gel, 40 g, 20% EtOAc/hexanes) to give a methyl 1-amino-3-chloro-1H-pyrrole-2-carboxylate (0.750 g, 69.0%) as a yellow solid. LCMS Condition B-23: retention time 0.68 min, [M+1]=175.1. 1H NMR (400 MHz, DMSO-d6) δ 3.80 (s, 3H), 6.11 (d, J=2.8 Hz, 1H), 6.28 (s, 2H), 7.06 (d, J=2.8 Hz, 1H).

1. stirringthe contents were stirred for another 30 min at −10° C
2. customThe solvents were removed under reduced pressure
3. extractionthe residue was extracted with MTBE
4. concentrationconcentrated under reduced pressure
5. customto give a brown solid
6. customThe crude residue was purified by CombiFlash (REDISEP®, silica gel, 40 g, 20% EtOAc/hexanes)