Synthesis research on the herbicide safe agent Furilazole

Furfural and nitromethane were utilized as raw materials for the synthesis of the herbicide-safe agent Furilazole through the Henry reaction, nitro reduction and addition-cyclization-acylation. A comprehensive investigation into the involved reaction processes was conducted, leading to the identification of barium hydroxide octahydrate as the catalyst for the Henry reaction. The continuous use methodology of the excess catalyst was determined through TGA/DSC curve analysis, and a rational purification method for Henry reaction products was proposed. The nitro reduction reaction employed Pd/C catalysis, while the subsequent addition-cyclization-acylation reaction was achieved in a single step. Five impurities affecting the reaction process were identified, and their potential mechanisms of formation were postulated. Optimization of synthetic process conditions was carried out for all involved reactions. The structures of intermediates, impurities, and products were characterized using NMR, HRMS, TGA/DSC and FTIR.