METHODS FOR PREPARING 5-(1-PIPERAZINYL)-BENZOFURAN-2-CARBOXAMIDE AND INTERMEDIATE COMPOUNDS Russian patent published in 2005 - IPC

FIELD: organic chemistry, chemical technology, pharmacy.

SUBSTANCE: invention relates to a method for preparing 5-(1-piperazinyl)-benzofuran-2-carboxamide. Method involves reaction of bromosalicylic aldehyde with compound of the formula (I): L-CH₂-COOR¹ (I) wherein L represents Cl, Br or J atoms, or reactive esterified group -OH; R¹ means (C₁-C₆)-alkyl or benzyl followed by reaction with formamide to yield 5-L-benzofuran-2-carboxamide (II) and the following its amination with R²-piperazine wherein R² represents hydrogen atom (H) or amino-protecting group in the presence of a catalyst based on transient metals; in case if R² is not H then R² is removed, and/or prepared 5-(1-piperazinyl)-benzofuran-2-carboxamide is converted to one of its salts by treatment with acid. Except for, the invention proposes two additional methods for preparing 5-(1-piperazinyl)-benzofuran-2-carboxamide and intermediate compounds of the formula (V): wherein R² represents H or amino-protected group; R³ means H or -CH₂R⁶; R⁴ and R⁵ in common represent carbonyl; R⁶ means -CN, -COOH, -COOR⁷ or -CONH₂; R⁷ means (C₁-C₆)-alkyl, and also their salts and solvates. Invention provides a new method for preparing the valuable intermediate compound used in preparing pharmaceutical preparations and increase of the yield of the end compound.

EFFECT: improved preparing methods.

6 cl, 10 ex