Synthesis method of 3-bromo-1-(3-chloro-2-pyridyl)-1H-pyrazole-5-formic acid

The invention relates to a synthesis method of 3-bromo-1-(3-chloro-2-pyridyl)-1H-pyrazole-5-formic acid, which comprises the following steps: taking 3-chloro-2-hydrazinopyridine and 3-cyano propiolic acid ester as initial raw materials, firstly carrying out cyclization reaction to obtain 3-hydroxy-1-(3-chloro-2-pyridyl)-5-cyano pyrazole, and then carrying out cyclization reaction on the 3-hydroxy-1-(3-chloro-2-pyridyl)-1H-pyrazole-5-formic acid to obtain the 3-bromo-1-(3-chloro-2-pyridyl)-1H-pyrazole-5-formic acid. The preparation method comprises the following steps: carrying out a bromination reaction to obtain 3-bromine-1-(3-chloro-2-pyridyl)-5-cyanopyrazole, carrying out a hydrolysis reaction to hydrolyze cyano into carboxylic acid, and adjusting the acid to obtain the 3-bromine-1-(3-chloro-2-pyridyl)-1H-pyrazole-5-formic acid. The method is simple in route, high in reaction selectivity in each step and high in total yield. 本发明涉及一种3-溴-1-(3-氯-2-吡啶基)-1H-吡唑-5-甲酸的合成方法，以3-氯-2-肼基吡啶和3-氰基丙炔酸酯为起始原料，先经环合反应获得3-羟基-1-