METHOD FOR PREPARING SUBSTITUTED O-ALKYLATED HEXAHYDRO-2H-CHROMENO[4,3-D]PYRIMIDINE-2,5(1H)-DIONES Russian patent published in 2023 - IPC C07D491/52 

FIELD: chemistry.

SUBSTANCE: invention relates to a process for the preparation of substituted O-alkylated hexahydro-2H-chromeno[4,3-d]pyrimidine-2,5(1H)-diones of the general formula

where R₁ = С₆Н₅, or 4-ClC₆H₄, or 4-МеОС₆Н₄, or 3-NO₂C₆H₄, R₂ = СН₃, or СН₂С(O)ОСН₃, or СН₂С₆Н₅. The proposed method consists in using diastereomeric pure 8-hydroxy-10b-methyl-4 -R ₁ -1,2,3,4,4a,10b-hexahydro-2H-chromeno[4,3-d]pyrimidine-2,5(1H)-diones, which are dissolved in DMF, then potassium carbonate is added successively (K₂CO₃) and one of the alkylating agents (CH₃I, or BrCH₂COOCH₃, or C₆H₅CH₂Cl) and the reaction mass is stirred at a temperature of 20…40°C for 2–4 hours. At the same time, when using C₆H₅CH₂Cl as an alkylating agent, the reaction mass is additionally stirred for another 2 hours at a temperature of 70…80°C until the reaction is complete. Next, the resulting reaction mass is cooled and isolated in cold water, the precipitate is filtered off and recrystallized from alcohol, dried in air at room temperature.

EFFECT: obtaining new chemical compounds of a sufficient degree of purity, which can be used as precursors for the synthesis of biologically active substances and drugs.

1 cl, 7 ex