CN106565562A - Synthesis process of 2-nitro-4-methylsulfonylbenzoic acid - Google Patents

Abstract

The invention provides a synthesis process of 2-nitro-4-methylsulfonylbenzoic acid with high yield and high product purity. The synthesis process comprises the steps of nitration, to be specific, adding 1400-1500 kg concentrated sulfuric acid, 350-360 kg methyl p-tolyl sulfone and 600-625 kg oxidized water-containing mother liquid into a nitration reaction kettle, adding 200-210 kg nitric acid uniformly drop by drop within 2-3 hours for nitration reaction, and keeping the heat for 60-70 min after adding of the nitric acid is finished to obtain a nitrated liquid; and oxidization, to be specific, importing the nitrated liquid into an oxidization reaction kettle, then adding a catalyst V2O5 and a nucleating agent into the oxidization reaction kettle, then adding 1240-1290 kg nitric acid drop by drop and controlling the reaction temperature at 142-146 DEG C, and keeping the heat for 1-2 hours after adding of the nitric acid is finished, then adding 800-1000 kg water after the reaction liquid is cooled to 100 DEG C and then cooling to 48-50 DEG C, then pressing and filtering to obtain an oxidization product and the oxidized water-containing mother liquid, rinsing the oxidization product circularly by using 1000-1100 kg water, refining the oxidization product for multiple times and separating out the nucleating agent, and then drying the oxidization product after being subjected to multiple times of refining at 55-70 DEG C to obtain the 2-nitro-4-methylsulfonylbenzoic acid.

Description

A kind of synthesis technique of 2- nitros -4- methyl sulfonylbenzoic acids

Technical field

The invention belongs to chemical field, and in particular to a kind of synthesis technique of 2- nitros -4- methyl sulfonylbenzoic acids.

Background technology

Mesotrione action target is p-hydroxyphenypyruvate dioxydenase (HPPD), is mainly used in preventing and kill off corn field Broad leaved weed and grassy weed, with herbicidal spectrum it is wide, Environmental compatibility is good, very low to mammal and aquatic toxicity, It is fool proof to corn and to rear stubble rotation crop without characteristics such as poisoning, it is front with the very big market demand and good application Scape.Additionally, mesotrione to prevent and kill off anti-three pyridine especially effective with the weeds of anti-sulfonylureas, weeds are in it and these type herbicides Between there is no cross resistance, this just provides convenience to herbicide Fruit variety in crop rotation.

At present, mesotrione typically carries out chloride by intermediate 2- nitro -4- methyl sulfonylbenzoic acids and condensation is reset It is prepared by reaction.And the synthesis of intermediate 2- nitro -4- methyl sulfonylbenzoic acids has various methods, the total reaction yield of these methods Preferably, 85% or so is may be up to, but still has larger room for promotion.And product purity is low, hardly result in accordance with quality requirement 2- nitro -4- methyl sulfonylbenzoic acids, i.e. product purity is poor, and polynitration compound impurity increases to next step synthesizing methyl sulphur humulone The danger of industrialized production is added.

The content of the invention

To solve the above problems, the invention provides the high 2- nitro -4- mesyl benzene of a kind of high income, product purity The synthesis technique of formic acid.

The synthesis technique of 2- nitros -4- methyl sulfonylbenzoic acids provided by the present invention, including step：

Nitrification：In nitration reaction kettle addition 1400～1500kg of the concentrated sulfuric acid, to 350～360kg of methylsulfonyltoluene and oxidation After 600～625kg of water-bearing mother liquor, uniform 200～210kg nitric acid that is added dropwise carries out nitration reaction in 2～3 hours, after completion of dropping Insulation 60～70 minutes, obtains nitrification liquid；

Oxidation：Nitrification liquid to be imported and add catalyst V2O5 and nucleator after oxidizing reactor, then it is added dropwise 1240～ 1290kg nitric acid, and controlling reaction temperature is 142～146 DEG C；1～2 hour is incubated after completion of dropwise addition；Reactant liquor is cooled to After 100 degree, add water and be cooled to again after 800～1000kg 48～50 degree, then press filtration obtains oxidation product and oxidation containing jellyfish Liquid, with 1000～1100kg of water circulation rinsing oxidation products；Oxidation product is repeatedly refined and nucleator is isolated, will be many afterwards It is secondary it is refined after oxidation product 2- nitro -4- methyl sulfonylbenzoic acids are dried to obtain at 55～70 DEG C.

Its except high income, product purity height in addition to, due to the reuse to oxidation mother liquor, it is possible to reduce the use of catalyst Amount, and the product ton consumption of fresh water can be reduced, while reducing waste water；And big shortening, reacting balance are easy to the time required to reacting Control.In addition, the presence of nucleator can promote crystallization further to shorten the reaction time, and during mother liquor reuse, part nucleator Can play a part of to promote crystallization in oxidation step again.

Preferably, in the oxidation step, the consumption of catalyst V2O5 is 4～5kg.

Preferably, it is uniform first in 14～16 hours that nitric acid 890 is added dropwise when nitric acid is added dropwise in the oxidation step ～920kg, while controlling reaction temperature is 144～146 degree；It is uniform in 12～14 hours again that 350～370kg nitric acid is added dropwise, Simultaneously controlling reaction temperature is 142～144 degree；1～2 hour is incubated after completion of dropwise addition.

Preferably, when the oxidation product is refined, NaOH solution is added to adjust pH value to 8.0～9.0 in oxidation product, To dissolve oxidation product, temperature is controlled in adition process for 55～60 DEG C, nucleator is filtered to isolate afterwards；Then put while hot Material centrifugation, is added dropwise hydrochloric acid and adjusts pH value to 1～2, is kept for 30～50 minutes in the range of 55～60 DEG C of temperature, after being cooled to 35 DEG C from The heart, rinsing, obtain final product refined 2- nitro -4- methyl sulfonylbenzoic acids.

Preferably, the nucleator is 1～10 micron of boron nitride powder.Boron nitride powder strong inert, non-mutability are lost Effect, therefore, it is possible to the use for preferably nucleator being reduced in fosterization mother liquor reuse.

Specific embodiment

Embodiment 1

In nitration reaction kettle 98% concentrated sulfuric acid 1400kg of addition, to methylsulfonyltoluene 360kg and oxidation water-bearing mother liquor 600kg Afterwards, uniform 68% nitric acid that 200kg is added dropwise carries out nitration reaction in 4 hours, and after completion of dropping 60 minutes are incubated, and is nitrified Liquid；

Nitrification liquid is imported 4kg catalyst V2O5 and 20kg granularities are added after oxidizing reactor in 1～10 micron of nitridation Boron powder, it is uniform in 14 hours that 68% nitric acid 920kg is added dropwise after being warming up to 142 degree, while controlling reaction temperature is 144 degree； 68% nitric acid of 370kg was uniformly added dropwise in 14 hours again, while controlling reaction temperature is 142 degree；Insulation 2 is little after completion of dropwise addition When.After reactant liquor is cooled to into 100 degree, adds water and be cooled to again after 800kg 48 degree, then press filtration obtains oxidation product and oxidation Water-bearing mother liquor, with water 1000kg circulation rinsing oxidation products；NaOH solution is added to adjust pH value to 8.0 in oxidation product, with molten Solution oxidation product, controls temperature for 55 DEG C in adition process, and filters to isolate nucleator；Then blowing centrifugation while hot, drop Plus hydrochloric acid adjusts pH value to 1, kept for 50 minutes at 55 DEG C of temperature, centrifugation, rinsing, obtain final product refined 2- nitre after being cooled to 35 DEG C Base -4- methyl sulfonylbenzoic acids；2- nitro -4- the methyl sulfonylbenzoic acids for being dried to obtain it at 70 DEG C after refining for three times are produced Product purity is 91.01%, and yield is 92.30%.

Embodiment 2

In nitration reaction kettle 98% concentrated sulfuric acid 1500kg of addition, to methylsulfonyltoluene 350kg and oxidation water-bearing mother liquor 625kg Afterwards, uniform 68% nitric acid that 210kg is added dropwise carries out nitration reaction in 5 hours, and after completion of dropping 70 minutes are incubated, and is nitrified Liquid；

Nitrification liquid is imported 5kg catalyst V2O5 and 17kg granularities are added after oxidizing reactor in 1～10 micron of nitridation Boron powder, it is uniform in 16 hours that 68% nitric acid 890kg is added dropwise after being warming up to 142 degree, while controlling reaction temperature is 146 degree； 68% nitric acid of 350kg was uniformly added dropwise in 12 hours again, while controlling reaction temperature is 144 degree；Insulation 1 is little after completion of dropwise addition When.After reactant liquor is cooled to into 100 degree, adds water and be cooled to again after 1000kg 50 degree, then press filtration obtains oxidation product and oxygen Change water-bearing mother liquor, with water 1100kg circulation rinsing oxidation products；NaOH solution is added to adjust pH value to 9.0 in oxidation product, with Dissolving oxidation product, controls temperature for 60 DEG C in adition process, and filters to isolate nucleator；Then blowing centrifugation while hot, Hydrochloric acid is added dropwise adjusts pH value to 2, is kept for 30 minutes under temperature 60 C, and centrifugation, rinsing, obtain final product refined 2- nitre after being cooled to 35 DEG C Base -4- methyl sulfonylbenzoic acids；2- nitro -4- the methyl sulfonylbenzoic acids for being dried to obtain it at 55 DEG C after refining for five times are produced Product purity is 90.33%, and yield is 92.56%.

Embodiment 3

In nitration reaction kettle 98% concentrated sulfuric acid 1450kg of addition, to methylsulfonyltoluene 355kg and oxidation water-bearing mother liquor 610kg Afterwards, uniform 68% nitric acid that 205kg is added dropwise carries out nitration reaction in 4.5 hours, and after completion of dropping 65 minutes are incubated, and is nitrified Liquid；

Nitrification liquid is imported and add 4.5kg catalyst V2O5 and 15kg granularities in 1～10 micron of nitrogen after oxidizing reactor Change boron powder, it is uniform in 15 hours that 68% nitric acid 900kg is added dropwise after being warming up to 142 degree, while controlling reaction temperature is 145 Degree；68% nitric acid of 350～370kg was uniformly added dropwise in 13 hours again, while controlling reaction temperature is 143 degree；Completion of dropwise addition It is incubated 1.5 hours afterwards.After reactant liquor is cooled to into 100 degree, adds water and be cooled to again after 900kg 49 degree, then press filtration obtains oxygen Change product and oxidation water-bearing mother liquor, with water 1050kg circulation rinsing oxidation products；NaOH solution is added to adjust pH in oxidation product It is worth to 8.5, to dissolve oxidation product, temperature is controlled in adition process for 57 DEG C, and filters to isolate nucleator；Then while hot Blowing is centrifuged, and hydrochloric acid is added dropwise and adjusts pH value to 1.5, is kept for 40 minutes in the range of 57 DEG C of temperature, centrifugation, drift after being cooled to 35 DEG C Wash, obtain final product refined 2- nitro -4- methyl sulfonylbenzoic acids；The 2- nitros for being dried to obtain it at 65 DEG C after refining for four times- 4- methyl sulfonylbenzoic acids product purity is 89.94%, and yield is 92.61%.

Finally it should be noted that：Various embodiments above only to illustrate technical scheme, rather than a limitation；To the greatest extent Pipe has been described in detail with reference to foregoing embodiments to the present invention, it will be understood by those within the art that：Its according to So the technical scheme described in foregoing embodiments can be modified, either which part or all technical characteristic are entered Row equivalent；And these modifications or replacement, do not make the essence disengaging various embodiments of the present invention technology of appropriate technical solution The scope of scheme.

Claims (5)

1. a kind of synthesis technique of 2- nitros -4- methyl sulfonylbenzoic acids, it is characterised in that including step：

Nitrification：Nitration reaction kettle add 1400～1500kg of the concentrated sulfuric acid, to 350～360kg of methylsulfonyltoluene and aoxidize it is aqueous After 600～625kg of mother liquor, uniform 200～210kg nitric acid that is added dropwise carries out nitration reaction in 2～3 hours, is incubated after completion of dropping 60～70 minutes, obtain nitrification liquid；

Oxidation：Nitrification liquid is imported and add catalyst V2O5 and nucleator after oxidizing reactor, then 1240～1290kg is added dropwise Nitric acid, and controlling reaction temperature is 142～146 DEG C；1～2 hour is incubated after completion of dropwise addition；After reactant liquor is cooled to into 100 degree, Add water and be cooled to again after 800～1000kg 48～50 degree, then press filtration obtains oxidation product and oxidation water-bearing mother liquor, uses water 1000～1100kg circulation rinsing oxidation products；Oxidation product is repeatedly refined and nucleator is isolated, will repeatedly be refined afterwards Oxidation product afterwards is dried to obtain 2- nitro -4- methyl sulfonylbenzoic acids at 55～70 DEG C.

2. synthesis technique as claimed in claim 1, it is characterised in that in the oxidation step, the consumption of catalyst V2O5 For 4～5kg.

3. synthesis technique as claimed in claim 2, it is characterised in that in the oxidation step, when nitric acid is added dropwise, exists first It is uniform in 14～16 hours that 890～920kg of nitric acid is added dropwise, while controlling reaction temperature is 144～146 degree；It is little 12～14 again When interior uniform dropwise addition 350～370kg nitric acid, while controlling reaction temperature be 142～144 degree；Insulation 1～2 is little after completion of dropwise addition When.

4. synthesis technique as claimed in claim 3, it is characterised in that when the oxidation product is refined, in oxidation product Add NaOH solution to adjust pH value to 8.0～9.0, to dissolve oxidation product, temperature is controlled in adition process for 55～60 DEG C, it After filter to isolate nucleator；Then blowing centrifugation while hot, is added dropwise hydrochloric acid and adjusts pH value to 1～2, in the range of 55～60 DEG C of temperature Kept for 30～50 minutes, centrifugation, rinsing, obtain final product refined 2- nitro -4- methyl sulfonylbenzoic acids after being cooled to 35 DEG C.

5. synthesis technique as claimed in claim 4, it is characterised in that the nucleator is 1～10 micron of boron nitride powder.