1-Benzyl-4-ethoxycarbonyl-4-methyl-3-pyrrolidone → 1-Benzyl-4-methylpyrrolidin-3-one

A mixture of 48.0 g (0.184 mole) of 1-benzyl-4-ethoxycarbonyl-4-methyl-3-pyrrolidone [prepared as described in Step (3) above] and 80 ml of concentrated hydrochloric acid was heated under reflux for 24 hours. The reaction mixture was then filtered, and the filtrate was concentrated by evaporation under reduced pressure. The residue was diluted with water and made alkaline by adding a 50% w/v aqueous solution of sodium hydroxide to pH 10, after which it was extracted with diethyl ether. The diethyl ether extract was dried and the solvent was then distilled from the extract under reduced pressure. The residue was purified by column chromatography through silica gel eluted with a 2.5:7.5 by volume mixture of ethyl acetate and toluene, to give 31.7 g of 1-benzyl-4-methyl-3-pyrrolidone as a red oil.

1. temperaturewas heated
2. temperatureunder reflux for 24 hours
3. filtrationThe reaction mixture was then filtered
4. concentrationthe filtrate was concentrated by evaporation under reduced pressure
5. additionThe residue was diluted with water
6. additionby adding a 50% w/v aqueous solution of sodium hydroxide to pH 10
7. extractionafter which it was extracted with diethyl ether
8. extractionThe diethyl ether extract
9. customwas dried
10. distillationthe solvent was then distilled from the
11. extractionextract under reduced pressure
12. customThe residue was purified by column chromatography through silica gel
13. washeluted with a 2.5:7.5 by volume mixture of ethyl acetate and toluene

ORD record

ord-5a9bc5973be445488c9a394d73458a8f

Source dataset

uspto-grants-1991_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04997943