Its preparation method is to put in hydrazine hydrate and ethylene glycol in the reactor, and put in 4-methyl 2-aminobenzothiazole hydrochloride under stirring (if it is 4-methyl-2-aminobenzothiazole, it also needs to be put into appropriate amount of hydrochloric acid). After feeding, the temperature was raised to 116°C for pre-steaming. At the same time, nitrogen was introduced. After the front fraction was collected, it was discarded after treatment. The collected fractions at 116-122 °C were low-boiling substances. The low-boiling substances were concentrated and applied mechanically. Nitrogen state, the reaction is over, stop the nitrogen flow, cool to 30 ° C, put it into a suction filter cylinder to remove the mother liquor under vacuum conditions, put the filter cake into a beating kettle, add water at 35 ° C for beating for 2 hours, and then put it into a suction filter cylinder and pump it out Beating water, then the filter cake is washed with water to the end point, and the washing water is removed by centrifugation to obtain the finished product. The mother liquor beating water concentrate in the reaction process is concentrated and analyzed by gas chromatography for the contents of hydrazine hydrate and ethylene glycol, which can then be incorporated into the next reaction.
|Sulfadimethoxine Sodium Salt|