METHOD FOR PREPARING N-ACYL-DERIVATIVES OF 4-AMINOANTIPYRINE Russian patent published in 2004 - IPC

FIELD: organic chemistry, chemical technology, pharmacy.

SUBSTANCE: invention relates to a method for synthesis of biologically active compounds, namely, to methods for preparing N-acyl-derivatives of 4-aminoantipyrine eliciting analgetic and anti-inflammatory effect. The condensation process of free acid with 4-aminoantipyrine is carried out in inert organic solvent not mixing with water and forming azeotrope with water in the absence of any condensing or moisture absorbing reagents, in the presence of catalytic amounts of strong acid catalysts, such as benzenesulfonic acids and toluenesulfonic acids. Water formed in the reaction process is distilled off by azeotrope with solvent wherein reaction is carried out and with recovery of solvent to reaction mass after separating water. Method provides stable high yields of products, simplifying isolation and purifying products, reducing number of technological procedures and reduced toxicity of technological process and waste formed.

EFFECT: improved preparing method.

2 cl, 2 tbl, 1 ex