METHOD FOR PREPARING PHOTOSENSIBILIZERS BASED ON CHLORINE CYCLOIMIDES P6 Russian patent published in 2017 - IPC C07D487/22 

FIELD: chemistry.

SUBSTANCE: invention relates to method for preparing compounds of formula , where n is 2-6, consisting in the reaction of purpurin 18 with aminoalcohol, wherein purpurin 18 dissolved in an organic solvent selected from a chlorinated aliphatic hydrocarbon is treated with 4-6-fold by moles of C₂-C₆-aminoalcohol at a temperature of 20°C until complete conversion of the original purpurin 18; the reaction mass is washed with water, dried and evaporated under reduced pressure, the resulting solid product containing the amide mixture is dissolved in trifluoroacetic anhydride and combined with 5% sodium hydrogencarbonate solution, the target product is extracted with dichloromethane, the organic phase is washed with water, dried and chromatographed on silica gel in the dichloromethane-aliphatic alcohol system preparing a compound solution of formula (I); the compound solution of formula (I) is evaporated under reduced pressure, the resulting solid product containing the compound of formula (I), purified by recrystallization from a solvent mixture of dichloromethane/petroleum ether, filtered off and dried.

EFFECT: preparing compounds of formula I in high yield.

5 cl, 4 ex