EFFECTIVE PROCESS FOR PRODUCING 6-CARBOXYBENZOXAZOLE DERIVATIVES Russian patent published in 2023 - IPC C07D263/57 C07D317/34 C07D493/18 C07C47/32 

FIELD: pharmaceuticals.

SUBSTANCE: invention relates to a method of producing a 6-carboxy-2-(3,5-dichlorophenyl)benzoxazole compound of formula I, wherein the method involves the reaction of a 4-amino-3-hydroxybenzoic acid compound of formula III with a 3,5-dichlorophenyl orthoester compound of formula II in the presence of an acid or base catalyst or in the absence of a catalyst to produce a compound of formula I wherein R¹ represents hydrogen or a carboxyl protecting group; and R^2a, R^2b and R^2c are each independently C₁-C₆ alkyl or any two of R^2a, R^2b and R^2c taken together are C₁-C₆ alkanediyl, or R^2a, R^2b and R^2c taken together represent C₃-C₁₀ alkantriyl. The invention also relates to intermediate compounds of formula II and a method of their preparation.

EFFECT: new effective method has been developed for obtaining a compound of formula I, which is used in medicine for the treatment of amyloid diseases.

53 cl, 1 dwg, 6 tbl, 59 ex