Reactions of 5-alkyl-and 5-aryl-3H-furan-2-ones with 1,3-and 1,4-binucleophiles of aromatic series were carried out for the first time under various conditions. In the presence of a base the reaction resulted in 1-R-1,3-dihydro-2Н-pyrrol-2-ones, under milder conditions intermediates were isolated, 4-aryl-4oxobutanamides. The structure of the latter was proved by spectral methods. By an example of 1-R-1,3dihydro-2Н-pyrrol-2-ones the possibility was demonstrated of their functionalization via introducing an aryldiazenyl fragment.