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

0.33 ml of NaHMDS solution (1.0 M in THF, 0.33 mmol) 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 (2f) (0.30 mmol) prepared by the Step 1 in a dropwise manner at −79° C. and stirred for 30 mins. After 0.3 ml of dimethyl sulfate 0.36 mmol) 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%).

1. customprepared by the Step 1 in a dropwise manner at −79° C.
2. stirringthe reaction mixture was stirred for 4 hrs at 0° C
3. extractionextracted with 7 ml of ethyl acetate
4. customto separate into an organic layer and water layer
5. washThe organic layer was washed with 2 ml of saturated NaHCO3 solution and 2 ml of saturated NaCl solution
6. dry with materialdried over anhydrous MgSO4
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customThe resultant was purified by Silica gel column chromatography with EtOAc as an eluant

ORD record

ord-c31d6509391b418bac4e240730adb956

Source dataset

uspto-grants-2010_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07846963B2