CN102603672A - Method for synthesizing tebuthiuron technical material - Google Patents
Method for synthesizing tebuthiuron technical material Download PDFInfo
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- CN102603672A CN102603672A CN2012100332440A CN201210033244A CN102603672A CN 102603672 A CN102603672 A CN 102603672A CN 2012100332440 A CN2012100332440 A CN 2012100332440A CN 201210033244 A CN201210033244 A CN 201210033244A CN 102603672 A CN102603672 A CN 102603672A
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Abstract
The invention discloses a method for synthesizing a tebuthiuron technical material. The method comprises the following steps: taking 5-tert-butyl-2-methylamino-1,3,4-thiadiazole as a starting material; carrying out salt forming reaction and photochemical reaction in an organic solvent to prepare N-methyl-N-(5-tert-butyl-1,3,4-thiadiazole) carbamyl chloride; and introducing monomethylamine gas into the N-methyl-N-(5-tert-butyl-1,3,4-thiadiazole) carbamyl chloride to generate the tebuthiuron. The method has the advantages of simplicity in process, low production cost, high product purity, high yield, high production safety and the like.
Description
Technical field
The present invention relates to a kind of compound method of tebuthiuron technical.
Background technology
Terbufos benzthiazuron, common name tebuthiuron, chemical name are 1-(5-tertiary butyl-1,3,4-thiadiazoles-2-yl)-1, the 3-dimethyl urea.Be a kind of broad-spectrum herbicide of preventing and kill off draft and gramineae plant, be mainly used in and prevent and kill off the bare place weeds, the shrub in pasture district, Gramineae in the sugarcane field and broadleaf weeds.
According to the domestic and foreign literature report, the compound method of terbufos benzthiazuron mainly contains three kinds at present.(1) the 4-thiadiazoles is a starting raw material with 5-tertiary butyl-2-methylamino--1,3 as disclosed among the USP us4283543, is solvent with toluene, drips the methyl isocyanate reaction and makes tebuthiuron technical.This method uses methyl isocyanate inflammable and explosive, and toxicity is very big, and boiling point is low, production is absolutely unsafe.(2) as disclosed with 5-tertiary butyl-2-methylamino--1,3 among the Chinese patent CN200910100138,4-thiadiazoles, Methylaminoformyl chloride are starting raw material, with toluene make solvent, triethylamine carries out condensation reaction as acid binding agent and makes tebuthiuron technical.But this method can be many because of the consumption that consumes a large amount of triethylamines and raw material Methylaminoformyl chloride, the high production cost that makes of price is higher.(3) as disclosed among the Chinese patent CN200710050307 with 5-tertiary butyl-2-methylamino--1; 3; 4-thiadiazoles and dihalide phosphinylidyne or derivatives thereof be raw material directly after 50 ℃ of reactions, under alkaline condition, make tebuthiuron technical then with the reaction of 40% aqueous methylamine solution.Because 5-tertiary butyl-2-methylamino--1,3 in this method, 4-thiadiazoles are directly by generating N-methyl-N-(5-tertiary butyl-1,3 with phosgene, two phosgene or TRIPHOSGENE 99.5 50 ℃ of reactions; The 4-thiadiazoles) urea chloride the time, can follow 5-tertiary butyl-2-methylamino--1,3 takes place; The reaction of 4-thiadiazoles and N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles) urea chloride generates N; The side reaction of N '-two [N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles-2-yl)] urea; When N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles) urea chloride reacts with 40% methylamine in alkaline aqueous solution in addition; Owing to the existence of moisture content is arranged in the system, can cause N-methyl-N-(5-tertiary butyl-1,3; The 4-thiadiazoles) urea chloride and water hydrolytic reactions are produced by product N, N '-two [N-methyl-N-(5-tertiary butyl-1; 3,4-thiadiazoles-2-yl)] urea.Therefore product yield is low, content is low, difficult separation and purification.
Therefore, how to improve tebuthiuron technical production security, reduce production costs, improve yield and content is the problem that those skilled in the art study always.
Summary of the invention
The object of the present invention is to provide that a kind of technology is simple, production cost is low, product purity is high, yield is high, the method for the synthetic tebuthiuron technical of production security.
Technical solution of the present invention is:
A kind of compound method of tebuthiuron technical is characterized in that: may further comprise the steps:
(1) with 5-tertiary butyl-2-methylamino--1,3, the 4-thiadiazoles is a starting raw material, in organic solvent, processes N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles) urea chloride through salt-forming reaction, photochmeical reaction;
(2) in N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles) urea chloride, feed Monomethylamine gas and carry out amination reaction generation terbufos benzthiazuron;
Reaction formula is following:
Described organic solvent is any one in toluene, YLENE, chlorobenzene, ethylene dichloride, the tetracol phenixin; The consumption of organic solvent is 5-tertiary butyl-2-methylamino--1,3,3～10 times of 4-thiadiazoles quality.
In the described salt-forming reaction, salt-forming reagent is any one in hydrochloric acid, sulfuric acid, phosphoric acid, the hydrogen chloride gas; The salt-forming reagent consumption is 5-tertiary butyl-2-methylamino--1,3,1～4 times of 4-thiadiazoles molar mass; 20 ℃～80 ℃ of salify temperature.
In the photochmeical reaction, the phosgene consumption is 5-tertiary butyl-2-methylamino--1,3,1～5 times of 4-thiadiazoles molar mass, and temperature of reaction is 40 ℃～100 ℃, 2～10 hours reaction times.
Feed exsiccant nitrogen after photochmeical reaction finishes, remove remaining phosgene and hydrogen chloride gas.
To intermediate N methyl-N-(5-tertiary butyl-1; 3,4-thiadiazoles) feed Monomethylamine gas in the urea chloride and carry out amination reaction, the consumption of Monomethylamine is N-methyl-N-(5-tertiary butyl-1; 3; The 4-thiadiazoles) 1～5 of the urea chloride molar mass times, temperature of reaction is 0 ℃～100 ℃, 2～5 hours reaction times.
Amination reaction directly adds entry after finishing in reactant, drip 10% hydrochloric acid regulation system pH value to 6～7 again; Being warming up to material then is dissolved in the organic layer fully; After the layering, organic layer is separated, decrease temperature crystalline, separation, dry the solid tebuthiuron technical.
The quality that adds entry is 5-tertiary butyl-2-methylamino--1,3,2～7 times of 4-thiadiazoles quality.
Present method and prior art relatively have following characteristics:
1, adopts mineral acid elder generation and 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles (I) salt-forming reaction; Feasible amino is adequately protected, and during again with phosgene reaction, has avoided by product N effectively; The generation of N '-two [N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles-2-yl)] urea.Product yield is high, and total recovery is (with 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles meter) more than 97%.
2, adopt gas Monomethylamine and N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles) urea chloride (III) to carry out amination reaction and generate terbufos benzthiazuron; Water and N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles) urea chloride (III) hydrolytic reactions when having solved the reaction of employing monomethylamine aqueous solution; Generate by product N; The problem of N '-two [N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles-2-yl)] urea.Quality product is excellent, and content reaches more than 98%.
3, adopting cheap phosgene, Monomethylamine is the synthetic terbufos benzthiazuron of raw material, has reduced production cost.Avoided simultaneously using inflammable, explosive, volatile hypertoxic hazardous chemical methyl isocyanate, made production safer.
Below in conjunction with embodiment the present invention is described further.
Embodiment
Embodiment 1
(1) in the 1000ml four-hole boiling flask, drops into toluene 500ml, 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles (I) 51.3g (0.3mol).Drip 31% technical hydrochloric acid 46g while stirring.Be warming up to the backflow azeotropic after dripping off and deviate from the water in the system, get 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles hydrochloride (II).
(2) with above-mentioned preparation 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles hydrochloride (II) toluene suspension liquid is cooled to 85 ℃, feeds phosgene with the speed of 1200ml/min～1400ml/min, logical light is after 2 hours, the material clear that becomes stops logical phosgene.Feed nitrogen rush residual phosgene and hydrogen chloride gas, N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles) urea chloride (III) toluene liquid.
(3) N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles) urea chloride (III) toluene liquid with above-mentioned preparation is cooled to below 20 ℃, feeds Monomethylamine gas, and serve as to control terminal point with pH value 8～9, is warming up to 70 ℃～80 ℃ insulation reaction then 1 hour.
(4) adding water 200ml stirs; And regulate pH value 6～7 with about 10% hydrochloric acid, be warming up to backflow, leave standstill branch sub-cloud water layer and middle layer, organic layer cool to crystallization below 5 ℃, centrifugal, dry white products tebuthiuron technical 67.5g; Content 98.5%; Yield 97.2% (with 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles meter).
Embodiment 2
(1) in the enamel still of 2000 liters, drop into toluene 1000L, 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles (I) 150kg under the whipped state, drips 31% technical hydrochloric acid 124kg.After dripping off, be warming up to backflow, azeotropic is deviate from the water in the system, gets 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles hydrochloride (II).
(2) with above-mentioned preparation 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles hydrochloride (II) toluene suspension liquid is cooled to 85 ℃, with 25m
3The flow of/h feeds phosgene, and logical photoresponse is after 4 hours, and the material clear that becomes stops logical phosgene.Feed nitrogen rush residual phosgene and hydrogen chloride gas.Get N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles) urea chloride (III) toluene liquid.
(3) N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles) urea chloride (III) toluene liquid with above-mentioned preparation is cooled to below 20 ℃, with 20m
3Flow about/h feeds Monomethylamine gas, and serve as to control terminal point with pH value 8～9, is warming up to 70 ℃～80 ℃ insulation reaction then 1 hour.
(4) adding water 500L stirs; And regulate pH value 6～7 with about 10% hydrochloric acid, be warming up to backflow, leave standstill branch sub-cloud water layer and middle layer, organic layer cool to crystallization below 5 ℃, centrifugal, dry white products tebuthiuron technical 246.5kg; Content 98.0%; Yield 97.8% (with 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles meter).
Embodiment 3
(1) in the 1000ml four-hole boiling flask, drops into toluene 500ml, 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles (I) 51.3g (0.3mol).Stir down, feed hydrogen chloride gas, get 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles hydrochloride (II) to saturated.
Logical light, amination, washing are with step (2), (3), (4) of embodiment 1.Gained tebuthiuron technical 68.0g, content 98.2%, yield 97.6% (with 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles meter).
Embodiment 4
(1) in the 1000ml four-hole boiling flask, drops into toluene 500ml, 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles (I) 51.3g (0.3mol).Stirring is cooled to 0～5 ℃, feeds phosgene 2 hours with 1200ml/min phosgene flow, slowly is warming up to 80～90 ℃ then, feeds phosgene reaction simultaneously, after material is transparent, feeds nitrogen rush residual phosgene and hydrogen chloride gas.Get N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles) urea chloride (III) toluene liquid.
Amination, washing are with step (3), (4) of embodiment 1.Gained tebuthiuron technical 58.0g, content 96.2%, yield 81.5% (with 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles meter).
Embodiment 5
Salify, photochemical step (1), (2) with embodiment 1.
Under the frozen water cooling, to N-methyl-N-(the 5-tertiary butyl-1,3 that makes; The 4-thiadiazoles) drips 40% monomethylamine aqueous solution 53.5g (0.69mol) in urea chloride (III) the toluene liquid; Dropwise half a hour, slowly is warming up to 30 ℃～40 ℃ reactions 1 hour, and amination reaction finishes.
Washing is with the step (4) of embodiment 1.Gained tebuthiuron technical 62.0g, content 94.2%, yield 85.3% (with 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles meter).
Embodiment 6
Salify, logical light, amination are with step (1), (2), (3) of embodiment 1
Amination reaction adds water 200ml after finishing, and regulates pH value to 6～7 with hydrochloric acid; Without heat up dividing water, directly stir be cooled to 5 ℃ of crystallizations, centrifugal, dry product terbufos benzthiazuron 68g, content 95.5%; Yield 95% (with 5-tertiary butyl-2-methylamino--1,3,4-thiadiazoles meter).
Claims (8)
1. the compound method of a tebuthiuron technical is characterized in that: may further comprise the steps:
(1) with 5-tertiary butyl-2-methylamino--1,3, the 4-thiadiazoles is a starting raw material, in organic solvent, processes N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles) urea chloride through salt-forming reaction, photochmeical reaction;
(2) in N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles) urea chloride, feed Monomethylamine gas and carry out amination reaction generation terbufos benzthiazuron.
2. the compound method of tebuthiuron technical according to claim 1, it is characterized in that: described organic solvent is any one in toluene, YLENE, chlorobenzene, ethylene dichloride, the tetracol phenixin; The consumption of organic solvent is 5-tertiary butyl-2-methylamino--1,3,3～10 times of 4-thiadiazoles quality.
3. the compound method of tebuthiuron technical according to claim 1 and 2, it is characterized in that: in the described salt-forming reaction, salt-forming reagent is any one in hydrochloric acid, sulfuric acid, phosphoric acid, the hydrogen chloride gas; The salt-forming reagent consumption is 5-tertiary butyl-2-methylamino--1,3,1～4 times of 4-thiadiazoles molar mass; 20 ℃～80 ℃ of salify temperature.
4. the compound method of tebuthiuron technical according to claim 1 and 2, it is characterized in that: in the photochmeical reaction, the phosgene consumption is 5-tertiary butyl-2-methylamino--1; 3; 1～5 times of 4-thiadiazoles molar mass, temperature of reaction is 40 ℃～100 ℃, 2～10 hours reaction times.
5. the compound method of tebuthiuron technical according to claim 1 and 2 is characterized in that: feed exsiccant nitrogen after photochmeical reaction finishes, remove remaining phosgene and hydrogen chloride gas.
6. the compound method of tebuthiuron technical according to claim 1 and 2 is characterized in that: to intermediate N methyl-N-(5-tertiary butyl-1,3; The 4-thiadiazoles) feeds Monomethylamine gas in the urea chloride and carry out amination reaction; The consumption of Monomethylamine is 1～5 times of N-methyl-N-(5-tertiary butyl-1,3,4-thiadiazoles) urea chloride molar mass; Temperature of reaction is 0 ℃～100 ℃, 2～5 hours reaction times.
7. the compound method of tebuthiuron technical according to claim 1 and 2; It is characterized in that: amination reaction directly adds entry after finishing in reactant, drip 10% hydrochloric acid regulation system pH value to 6～7 again; Being warming up to material then is dissolved in the organic layer fully; After the layering, organic layer is separated, decrease temperature crystalline, separation, dry the solid tebuthiuron technical.
8. the method for a kind of synthetic tebuthiuron technical according to claim 7, it is characterized in that: the quality that adds entry is 5-tertiary butyl-2-methylamino--1,3,2～7 times of 4-thiadiazoles quality.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103288777A (en) * | 2013-05-28 | 2013-09-11 | 浙江禾田化工有限公司 | Synthesis method of key intermediate of tebuthiuron, namely 2-methylamino-5-tert-butyl-1, 3, 4-thiadiazole |
| CN105638711A (en) * | 2016-03-04 | 2016-06-08 | 西华大学 | Synergism weeding composition |
| CN105669592A (en) * | 2016-03-21 | 2016-06-15 | 盐城南方化工有限公司 | Tebuthiuron synthesis method |
| CN106397354A (en) * | 2016-08-31 | 2017-02-15 | 盐城南方化工有限公司 | Method for improving flowability of tebuthiuron crystal |
| CN108794427A (en) * | 2018-07-13 | 2018-11-13 | 江苏快达农化股份有限公司 | A kind of synthetic method of 1,3,4- thiadiazoles derivatives |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113620905A (en) * | 2021-09-14 | 2021-11-09 | 江苏快达农化股份有限公司 | Industrial production method of tebuthiuron technical |
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| CN101597269A (en) * | 2009-06-24 | 2009-12-09 | 浙江一帆化工有限公司 | A kind of method for synthesizing tebuthiuron technical |
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| US4283543A (en) * | 1979-10-19 | 1981-08-11 | Morton-Norwich Products, Inc. | Process for preparing the compound 5-t-butyl-2-methylamino-1,3,4-triadiazole |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103288777A (en) * | 2013-05-28 | 2013-09-11 | 浙江禾田化工有限公司 | Synthesis method of key intermediate of tebuthiuron, namely 2-methylamino-5-tert-butyl-1, 3, 4-thiadiazole |
| CN105638711A (en) * | 2016-03-04 | 2016-06-08 | 西华大学 | Synergism weeding composition |
| CN105669592A (en) * | 2016-03-21 | 2016-06-15 | 盐城南方化工有限公司 | Tebuthiuron synthesis method |
| CN105669592B (en) * | 2016-03-21 | 2019-04-12 | 盐城南方化工有限公司 | A kind of synthetic method of terbufos benzthiazuron |
| CN106397354A (en) * | 2016-08-31 | 2017-02-15 | 盐城南方化工有限公司 | Method for improving flowability of tebuthiuron crystal |
| CN108794427A (en) * | 2018-07-13 | 2018-11-13 | 江苏快达农化股份有限公司 | A kind of synthetic method of 1,3,4- thiadiazoles derivatives |
| CN108794427B (en) * | 2018-07-13 | 2022-07-29 | 江苏快达农化股份有限公司 | Synthetic method of 1,3, 4-thiadiazole derivative |
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