Dimethyl Sulfate → Methyl 3-(1-methyl-2-oxo-2,5-dihydro-1H-pyrrol-3-yl)propanoate

Participants

Reaction Steps

0.33 ml of NaHMDS solution (1.0 M in THF, 0.33 mM) was added to 0.6 ml of THF solution containing 50 mg of 3-(2-oxo-2,5-dihydro-1H-pyrrol-3-yl)-propionic acid methyl ester (20 (0.295 mM) prepared by the Step 1 in a dropwise manner at −79° C. and stirred for 30 mins. After 0.3 ml of dimethyl sulfate 0.359 mM) was added thereto, the reaction mixture was stirred for 4 hrs at 0° C. Then the resulting mixture was dissolved in 2 ml of saturated NH4Cl solution and extracted with 7 ml of ethyl acetate to separate into an organic layer and water layer. The organic layer was washed with 2 ml of saturated NaHCO3 solution and 2 ml of saturated NaCl solution, dried over anhydrous MgSO4, filtered and concentrated in vacuo. The resultant was purified by Silica gel column chromatography with EtOAc as an eluant to give 18 mg of 3-(1-methyl-2-oxo-2,5-dihydro-1H-pyrrol-3-yl)-propionic acid methyl ester (2g) (yield: 33%).

Provenance & Evidence