Experimental and theoretical studies on the synthesis of 1,4,5-trisubstituted pyrrolidine-2,3-diones

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Nguyen Ngoc Tri,
• Luc Van Meervelt,
• Nguyen Tien Trung and
• Wim Dehaen

Beilstein J. Org. Chem. 2022, 18, 1140–1153, doi:10.3762/bjoc.18.118

• . Keywords: 4-acetyl-3-hydroxy-3-pyrroline-2-ones; 1,5-dihydro-2H-pyrrol-2-ones; pyrrolidine-2,3-dione; 2-pyrrolidinone derivative; 3-pyrroline-2-one; Introduction 2-Pyrrolidone, also known as γ-lactam, is a five-membered heterocyclic ring containing four carbon and one nitrogen atoms [1]. This γ-lactam

• amounts of 2 and 3 unchanged. However, increasing the concentration of aniline (2) in acetic acid to 0.75 M while keeping the amounts of 1 and 3 constant at 0.5 M resulted in a slight decrease of the yield (67%) of 2-pyrrolidinone derivative 4a (Table 1). Therefore, the ratio 1.5:1:1 of reactants, the

• signals of the aromatic carbons, the 13C NMR spectra of these compounds in DMSO-d6 also exhibited broad peaks at around 30 ppm and 191 ppm. The NMR spectra of the 2-pyrrolidinone derivative 4c were also recorded in CDCl3 and its 1H NMR spectrum is similar to the one observed in DMSO-d6. However, the 13C