Safe and continuous production method of sulphaguanidine

Abstract

The invention provides a safe and continuous production method of sulphaguanidine. The method comprises the following steps: (a) proportionally mixing industrial sulfanilamide, sodium carbonate and guanidine nitrate at normal temperature to obtain a mixed raw material; (b) heating the mixed raw material to 100 to 145 DEG C under the pressure condition of 0.06 to 0.08 MPa so as to preheat the mixed raw material to obtain a semi-solid mixture; (c) continuously heating the mixture to 150-165 DEG C under the pressure condition of 0.01-0.05 MPa, so that the mixture is subjected to chemical reaction in a slurry state; and (d) introducing nitrogen to cool the product in the step (c) to obtain a sulphaguanidine crude product. According to the continuous reactor, the problems that a reaction vessel is large, the online quantity of materials is large, the online time of the materials is long, the stirring effect is poor, the heat transfer effect is poor and the like due to the fact that a reaction kettle cannot be used for continuously carrying out chemical reaction and cannot effectively control material mixing and reaction procedures can be solved, and the problems can be well solved by using the continuous reactor, so that the safety performance is improved.

Description

technical field [0001] The invention belongs to the field of chemical raw material medicine production process, relates to a production method of sulfamidine, and in particular relates to a safe continuous production method of sulfamidine. Background technique [0002] The Chinese invention patent whose application number is 201210584928.X discloses a production process of medicinal sulfamidine, and sequentially puts in prescribed amounts of sulfonamide, sodium carbonate and guanidine nitrate (the molar ratio of feeding is 1.2-1.5:1.0:1.5-1.8), And add catalyst and co-catalyst, heat, heat up to 120 ° C to open vacuum pumping; continue to heat up to 125 ~ 145 ° C to completely melt the material, seal the reaction system, keep the reaction for 1 ~ 3 hours, add purified water equal to the weight of the raw material, stir , naturally cooled to 50 ℃, add the NaOH aqueous solution that the content is 29% (the solution weight is 0.2~0.4 times of the raw material weight), be cooled ...

AI Technical Summary

Problems solved by technology

The above-mentioned heating reaction process is usually carried out in a closed reactor. Guanidine nitrate as a raw material remains in the reaction system due to incomplete reaction and excess guanidine nitrate in the process ratio. Free guanidine will be produced in the later stage of the reaction. It is easy to decompose at high temperature, releases a large amount of decomposition heat, further promotes the decomposition of guanidine nitrate, increases the pressure in the reactor, and may cause an explosion risk in severe cases

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