| production method | the preparation method is to sequentially quantify 1,2, 4-triazole, sodium hydroxide and toluene were added to the reaction vessel, and the temperature was raised to reflux by stirring, and the water generated by the reaction was removed by reflux. When the separated water reaches the theoretical amount, the temperature in the kettle rises to 110 ℃ and the temperature is cooled to 50 ℃. Add a quantitative amount of monochlorenatone, react at 70~75 ℃ for 5H, cool and filter, A part of the filtrate was freed from the solvent to obtain a crude oxazolone solution, and a quantitative amount of hydrochloric acid was added dropwise to the solution. After stirring for 2H, the solution was cooled and crystallized, filtered, and the filtrate was layered and then the solvent was applied, the filter cake was oxazolone hydrochloride. Then put into the reaction kettle, add quantitative solvent and dilute alkali solution for neutralization and extraction, and the end point of neutralization is pH = 6~7, then keep the temperature between 50~55 ℃ and stir for 1H, and let stand to remove the lower wastewater, the solvent layer is an oxazolone solution, which is dedissolved after reflux dehydration. |
