A kind of preparation method of bentazone sodium salt pulvis
Technical field
The present invention relates to Chemicals preparation method technical field, specifically belong to a kind of preparation method of bentazone sodium salt pulvis.
Background technology
Bentazone is a kind of widely used low toxicity herbicide, and its mode of action, mechanism mainly realize with the bentazone sodium salt: the contact killing type tool is postemergence weed control optionally, is used for cauline leaf processing in seedling stage, works by the blade contact.Dry land is used, and is transmitted to inhibited photosynthesis in the chloroplast(id) by the blade face infiltration first.Use in the paddy field, can pass through root absorption again by the blade face infiltration, is transmitted to cauline leaf, strongly hinders weeds photosynthesis and water metabolism, causes nutrition hungry, makes physiological function lack of proper care and cause death.Effective constituent is detoxified to active weak glycoconjugates metabolism in the tolerable crop body, to crop safety.8~16 all bentazones can be decomposed by microorganism in soil after the dispenser.Can be used for the crops such as paddy rice, soybean, peanut, wheat, in the structure of agricultural production of China, played great function.It is first output bentazone raw pesticide that tradition is used, and more former medicine is made aqua, and this method produces a large amount of sour waters, and expends soda acid water, is unfavorable for production cost.
Summary of the invention
The purpose of this invention is to provide a kind of preparation method of bentazone sodium salt pulvis, overcome the deficiencies in the prior art, method is convenient and practical, saves the preparation method of cost, the bentazone sodium salt pulvis that can be mass-produced.
The technical solution used in the present invention is as follows:
A kind of preparation method of bentazone sodium salt pulvis, take isatoic anhydride as raw material, first in reactions such as the ethylene dichloride solvent system are synthetic through superamide, sulfonation is synthetic, closed loop is synthetic, the first step finishes the synthetic rear organic phase washing of closed loop, and organic phase is added suitable quantity of water for entering to extract still, slowly add alkali and regulate PH=8~9 o'clock, stop to add alkali, stir repetition measurement PH=8 half an hour~9, stop stirring and leave standstill;
Second step, treat the layering of the first step solution left standstill: get that the upper water phase materials is standby to enter concentration kettle, water bentazone content is surveyed in sampling, calculate according to water bentazone content concentrated, concentrated after water bentazone content 〉=48% reach requirement;
The 3rd step, the concentrated end, material is crossed to the cooling still, stirs fast logical salt solution and is cooled to 9-11 ℃, and is overanxious to crystallization kettle through sheet frame, the excessively complete sheet frame that dries up.
The 4th step, crystallization kettle is opened the cooling of chuck salt solution, need 2~3 hours early stages about slow cooling to 0 ℃, later stage salt solution valve wide open, when treating that temperature is down to-5 ℃ of left and right sides, whether have solid separate out, until reduce cooling rate after having solid to separate out if observing in the still, stirred 30 minutes, confirming has a large amount of materials to separate out;
The 5th step, separate out material and put into whizzer and directly dry, after drying the bentazone sodium salt through flash evaporation drying, for the first time normal temperature flash distillation, for the second time control 50~60 ℃ of flash distillations of temperature and add the bentazone solid additive, 100~110 ℃ of flash distillations of for the third time temperature control get finished product bentazone sodium salt;
The 6th step, with the bentazone sodium salt packing that steaming obtains, large packing, big area is used or the water soluble film small packages directly uses.
Compared with the prior art, beneficial effect of the present invention is as follows:
Preparation method of the present invention can obtain adding the bentazone sodium salt pulvis that water directly uses.This bentazone sodium salt pulvis is compared with the bentazone aqua, because be to add water when using, so have great advantage at transportation cost.
Embodiment
A kind of preparation method of bentazone sodium salt pulvis, take isatoic anhydride as raw material, first in reactions such as the ethylene dichloride solvent system are synthetic through superamide, sulfonation is synthetic, closed loop is synthetic, the first step finishes the synthetic rear organic phase washing of closed loop, and organic phase is added suitable quantity of water for entering to extract still, slowly add alkali and regulate PH=8~9 o'clock, stop to add alkali, stir repetition measurement PH=8 half an hour~9, stop stirring and leave standstill;
Second step, treat the layering of the first step solution left standstill: get that the upper water phase materials is standby to enter concentration kettle, water bentazone content is surveyed in sampling, calculate according to water bentazone content concentrated, concentrated after water bentazone content 〉=48% reach requirement;
The 3rd step, the concentrated end, material is crossed to the cooling still, stirs fast logical salt solution and is cooled to 9-11 ℃, and is overanxious to crystallization kettle through sheet frame, the excessively complete sheet frame that dries up.
The 4th step, crystallization kettle is opened the cooling of chuck salt solution, need 2~3 hours early stages about slow cooling to 0 ℃, later stage salt solution valve wide open, when treating that temperature is down to-5 ℃ of left and right sides, whether have solid separate out, until reduce cooling rate after having solid to separate out if observing in the still, stirred 30 minutes, confirming has a large amount of materials to separate out;
The 5th step, separate out material and put into whizzer and directly dry, after drying the bentazone sodium salt through flash evaporation drying, for the first time normal temperature flash distillation, for the second time control 50~60 ℃ of flash distillations of temperature and add the bentazone solid additive, 100~110 ℃ of flash distillations of for the third time temperature control get finished product bentazone sodium salt;
The 6th step, with the bentazone sodium salt packing that steaming obtains, large packing, big area is used or the water soluble film small packages directly uses.
Now with organic phase after closed loop is synthetic, washing finishes, and enters to extract still and adds suitable quantity of water organic phase is standby, slowly adds alkali and regulates PH=8~9 o'clock, stops to add alkali, stirs repetition measurement PH=8 half an hour~9, stops stirring and leaves standstill; Get and extract after the layering water 300g (content 20%) and pour into and obtain the 120g water after concentrated in the 250ml flask, with 9-11 ℃ of its fast cooling, and suction filtration obtains filtrate.Slow cooling-5 ℃ also produces a large amount of solids, and suction filtration obtains bentazone sodium salt crude product, and at last baking is dried, and adds in proportion solid-state auxiliary agent and grinds and evenly can obtain bentazone sodium salt pulvis.