2-Pyrrolidone → 4-[2-(2-oxopyrrolidin-1-yl)ethoxy]benzoic acid

2-Pyrrolidinone (0.859 mL, 11.3 mmol, 2.6 eq) was added to a suspension of sodium hydride (452 mg of 60% w/w, 11.3 mmol, 2.6 eq.) in THF (10 mL). After 1 h, the suspension of the sodium salt of 2-pyrrolidinone thus formed was added to a solution of methyl 4-(2-bromoethoxy)benzoate (1.17 g, 4.52 mmol) and a catalytic amount of tetrabutylammonium iodide in dry THF (10 mL). The reaction was heated at reflux for 18 h. The reaction mixture was concentrated under reduced pressure then the residue partitioned between ethyl acetate (150 mL) and 2 N sodium hydroxide (50 mL). The aqueous layer was made acidic to pH 3 with conc. HCl; then the solvent was removed under reduced pressure. The resulting solid was triturated with ethyl acetate to give the acid as a white solid (523 mg, 46%).

1. customthus formed
2. temperatureThe reaction was heated
3. temperatureat reflux for 18 h
4. concentrationThe reaction mixture was concentrated under reduced pressure
5. customthe residue partitioned between ethyl acetate (150 mL) and 2 N sodium hydroxide (50 mL)
6. customthen the solvent was removed under reduced pressure
7. customThe resulting solid was triturated with ethyl acetate

ORD-Eintrag

ord-27c4a2429e57477e91c93580fa16e99d

Quelldatensatz

uspto-grants-2003_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06541499B1