METHOD FOR PREPARING A THIO DERIVATIVE OF PYRROLIDINE-2,5-DIONE WITH A QUINAZOLINE FRAGMENT Russian patent published in 2023 - IPC C07D401/12 A61K31/517 A61P31/14 

FIELD: organic chemistry.

SUBSTANCE: method for producing thio derivatives of pyrrolidine-2,5-diones with a quinazoline fragment of general Formula (I), exhibiting antiviral inhibitory activity against the main protease M^pro of the beta coronavirus SARS-CoV-2. In the general Formula I, R₁ is phenyl; R₂, R₃, R₄ represent a substituent selected from hydrogen, C1-C2 alkyl, C1-C2 alkoxy, chlorine; R5 is naphthyl or phenyl, optionally substituted once or twice with C1-C2 alkyl, halogen, methoxy, ethoxy. The method consists of first adding 1-3 drops of triethylamine to a solution containing 0.01 mol of the corresponding 2-mercaptoquinazoline and 20 ml of absolute methanol, then adding in small portions from 0.01 to 0.011 mol of N-arylmaleimide, the resulting reaction mixture is stirred for 1 h, boiled for 3-4 h, cooled, the precipitate is filtered off and recrystallized from methanol.

EFFECT: obtaining thio derivatives of pyrrolidine-2,5-diones with a quinazoline fragment in high yields (up to 88%) using a simple procedure for their isolation from the reaction mass by simple filtration without the use of more labor-intensive chromatographic methods.

1 cl, 1 tbl, 11 ex