CN115286593B - Preparation method of dibenzothiazyl disulfide serving as rubber vulcanization accelerator - Google Patents
Preparation method of dibenzothiazyl disulfide serving as rubber vulcanization accelerator Download PDFInfo
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- AFZSMODLJJCVPP-UHFFFAOYSA-N dibenzothiazol-2-yl disulfide Chemical compound C1=CC=C2SC(SSC=3SC4=CC=CC=C4N=3)=NC2=C1 AFZSMODLJJCVPP-UHFFFAOYSA-N 0.000 title claims abstract description 53
- 238000013040 rubber vulcanization Methods 0.000 title claims abstract description 10
- 238000002360 preparation method Methods 0.000 title claims abstract description 9
- 238000006243 chemical reaction Methods 0.000 claims abstract description 44
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 30
- 238000002844 melting Methods 0.000 claims abstract description 26
- 230000008018 melting Effects 0.000 claims abstract description 26
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims description 99
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 58
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 50
- 238000003756 stirring Methods 0.000 claims description 45
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 claims description 44
- 229910052757 nitrogen Inorganic materials 0.000 claims description 29
- CHQMHPLRPQMAMX-UHFFFAOYSA-L sodium persulfate Substances [Na+].[Na+].[O-]S(=O)(=O)OOS([O-])(=O)=O CHQMHPLRPQMAMX-UHFFFAOYSA-L 0.000 claims description 25
- LCPVQAHEFVXVKT-UHFFFAOYSA-N 2-(2,4-difluorophenoxy)pyridin-3-amine Chemical compound NC1=CC=CN=C1OC1=CC=C(F)C=C1F LCPVQAHEFVXVKT-UHFFFAOYSA-N 0.000 claims description 24
- YXIWHUQXZSMYRE-UHFFFAOYSA-N 1,3-benzothiazole-2-thiol Chemical compound C1=CC=C2SC(S)=NC2=C1 YXIWHUQXZSMYRE-UHFFFAOYSA-N 0.000 claims description 22
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 claims description 22
- 235000019253 formic acid Nutrition 0.000 claims description 22
- 239000000843 powder Substances 0.000 claims description 20
- 239000007864 aqueous solution Substances 0.000 claims description 15
- 239000007789 gas Substances 0.000 claims description 15
- 239000012065 filter cake Substances 0.000 claims description 14
- 238000010992 reflux Methods 0.000 claims description 14
- 229910001220 stainless steel Inorganic materials 0.000 claims description 14
- 239000010935 stainless steel Substances 0.000 claims description 14
- 238000005406 washing Methods 0.000 claims description 14
- 238000004128 high performance liquid chromatography Methods 0.000 claims description 13
- 238000001514 detection method Methods 0.000 claims description 11
- WIWBLJMBLGWSIN-UHFFFAOYSA-L dichlorotris(triphenylphosphine)ruthenium(ii) Chemical compound [Cl-].[Cl-].[Ru+2].C1=CC=CC=C1P(C=1C=CC=CC=1)C1=CC=CC=C1.C1=CC=CC=C1P(C=1C=CC=CC=1)C1=CC=CC=C1.C1=CC=CC=C1P(C=1C=CC=CC=1)C1=CC=CC=C1 WIWBLJMBLGWSIN-UHFFFAOYSA-L 0.000 claims description 11
- 238000001914 filtration Methods 0.000 claims description 8
- 238000001035 drying Methods 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 3
- 238000005303 weighing Methods 0.000 claims 1
- 238000007254 oxidation reaction Methods 0.000 abstract description 17
- 239000003960 organic solvent Substances 0.000 abstract description 14
- 230000003647 oxidation Effects 0.000 abstract description 14
- 230000009467 reduction Effects 0.000 abstract description 8
- 239000012046 mixed solvent Substances 0.000 abstract description 4
- 239000002994 raw material Substances 0.000 abstract description 3
- 239000012535 impurity Substances 0.000 description 15
- 238000000034 method Methods 0.000 description 12
- 239000000203 mixture Substances 0.000 description 10
- 239000003054 catalyst Substances 0.000 description 9
- 238000006722 reduction reaction Methods 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 8
- 239000007800 oxidant agent Substances 0.000 description 8
- 230000001590 oxidative effect Effects 0.000 description 8
- 230000008569 process Effects 0.000 description 8
- 239000000047 product Substances 0.000 description 8
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 7
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 6
- 239000003638 chemical reducing agent Substances 0.000 description 6
- 238000010531 catalytic reduction reaction Methods 0.000 description 5
- 239000008096 xylene Substances 0.000 description 5
- 239000006227 byproduct Substances 0.000 description 4
- 239000012043 crude product Substances 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 238000007670 refining Methods 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000011261 inert gas Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000001603 reducing effect Effects 0.000 description 3
- 239000012279 sodium borohydride Substances 0.000 description 3
- 229910000033 sodium borohydride Inorganic materials 0.000 description 3
- 238000012546 transfer Methods 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- -1 dichloro tri (triphenylphosphine) ruthenium Chemical compound 0.000 description 2
- 229910017053 inorganic salt Inorganic materials 0.000 description 2
- LPXPTNMVRIOKMN-UHFFFAOYSA-M sodium nitrite Chemical compound [Na+].[O-]N=O LPXPTNMVRIOKMN-UHFFFAOYSA-M 0.000 description 2
- GEHJYWRUCIMESM-UHFFFAOYSA-L sodium sulfite Chemical compound [Na+].[Na+].[O-]S([O-])=O GEHJYWRUCIMESM-UHFFFAOYSA-L 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- RIOQSEWOXXDEQQ-UHFFFAOYSA-N triphenylphosphine Chemical compound C1=CC=CC=C1P(C=1C=CC=CC=1)C1=CC=CC=C1 RIOQSEWOXXDEQQ-UHFFFAOYSA-N 0.000 description 2
- RXCMFQDTWCCLBL-UHFFFAOYSA-N 4-amino-3-hydroxynaphthalene-1-sulfonic acid Chemical compound C1=CC=C2C(N)=C(O)C=C(S(O)(=O)=O)C2=C1 RXCMFQDTWCCLBL-UHFFFAOYSA-N 0.000 description 1
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000012847 fine chemical Substances 0.000 description 1
- VKYKSIONXSXAKP-UHFFFAOYSA-N hexamethylenetetramine Chemical compound C1N(C2)CN3CN1CN2C3 VKYKSIONXSXAKP-UHFFFAOYSA-N 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000012074 organic phase Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 238000011165 process development Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000012429 reaction media Substances 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 229910052707 ruthenium Inorganic materials 0.000 description 1
- UREFKUKELTYZEO-UHFFFAOYSA-N ruthenium;triphenylphosphane Chemical compound [Ru].C1=CC=CC=C1P(C=1C=CC=CC=1)C1=CC=CC=C1.C1=CC=CC=C1P(C=1C=CC=CC=1)C1=CC=CC=C1.C1=CC=CC=C1P(C=1C=CC=CC=1)C1=CC=CC=C1 UREFKUKELTYZEO-UHFFFAOYSA-N 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 235000010288 sodium nitrite Nutrition 0.000 description 1
- 235000010265 sodium sulphite Nutrition 0.000 description 1
- 239000002910 solid waste Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000004073 vulcanization Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
- 238000004383 yellowing Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D277/00—Heterocyclic compounds containing 1,3-thiazole or hydrogenated 1,3-thiazole rings
- C07D277/60—Heterocyclic compounds containing 1,3-thiazole or hydrogenated 1,3-thiazole rings condensed with carbocyclic rings or ring systems
- C07D277/62—Benzothiazoles
- C07D277/68—Benzothiazoles with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached in position 2
- C07D277/70—Sulfur atoms
- C07D277/76—Sulfur atoms attached to a second hetero atom
- C07D277/78—Sulfur atoms attached to a second hetero atom to a second sulphur atom
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Catalysts (AREA)
Abstract
The invention provides a preparation method of a rubber vulcanization accelerator dibenzothiazyl disulfide, which takes crude M as a raw material and takes a mixed solvent of water and an organic solvent as a medium to prepare the dibenzothiazyl disulfide with high purity through reduction decoloration reaction and two-stage oxidation, wherein the purity is more than 99%, the free M is less than 0.2%, and the melting point is more than or equal to 181 ℃.
Description
Technical Field
The invention relates to a preparation technology of fine chemicals, in particular to a preparation method of a rubber vulcanization accelerator, and specifically relates to a preparation method of dibenzothiazyl disulfide serving as the rubber vulcanization accelerator.
Background
Dibenzothiazyl Disulfide (DM) is used as a main vulcanization accelerator which is not replaced at present in the rubber vulcanization accelerator industry, and the green and environment-friendly process development of the dibenzothiazyl Disulfide (DM) is the focus of the industry.
At present, in the production technology of the rubber vulcanization accelerator dibenzothiazyl Disulfide (DM), 2-mercaptobenzothiazole (M) is taken as a raw material at present in China, and the following 2 production routes mainly exist.
(1) The two-step synthesis process comprises the following steps: (1) The crude product of the 2-mercaptobenzothiazole and alkaline compounds such as sodium hydroxide, ammonia water and the like form corresponding 2-mercaptobenzothiazole salt; (2) purifying by steps of filtering, decoloring, extracting and the like; (3) The 2-mercaptobenzothiazole salt reacts with an oxidant to oxidize to form dibenzothiazyl Disulfide (DM).
The main focus of the current research of this process is the purification in step (2) and the oxidation in step (3). As in patent CN 107365281B, after 2-mercaptobenzothiazole is dissolved in ammonia, insoluble matter is filtered out, under the action of a composite catalyst of urotropine and 1-amino-2-naphthol-4-sulfonic acid, crude dibenzothiazole disulfide is obtained by oxidation with hydrogen peroxide, and then dibenzothiazole disulfide is obtained after recrystallization with toluene or acetone.
The disadvantage of this process is: (1) The purity of DM products obtained by subsequent oxidation is low because the refining of crude M is not thorough; (2) Acid is usually added simultaneously when 2-mercaptobenzothiazole salt is oxidized, so that partial 2-mercaptobenzothiazole salt reacts with acid to generate 2-mercaptobenzothiazole, and free M in DM exceeds standard; (3) the operation is complex and has great potential safety hazard.
(2) The one-step synthesis process comprises the following steps: for example, in the "key technology for industrial production of medicinal dibenzothiazyl Disulfide (DM)" in the article of Menngdong, special active carbon is added into a TH solution in which M is dissolved, and then the mixture is heated, boiled, filtered and recrystallized to obtain purified M, and then the purified M is dissolved in a solvent, and then sodium nitrite and sulfuric acid are added, and oxygen is introduced for oxidation to obtain the DM. The 2-mercaptobenzothiazole (M) is oxidized with hydrogen peroxide in an organic solvent to give dibenzothiazyl Disulfide (DM) as described in patent CN 104592155A.
The disadvantages of this process are: (1) M purified from crude M is used as a starting material, but M is more difficult to oxidize than M sodium or ammonium salts and is therefore generally difficult to fully oxidize; (2) The refining process of the crude product M is complicated, the refining difficulty is high, and more solid wastes are generated.
Disclosure of Invention
In order to overcome the technical defects in the prior art, the invention provides a preparation method of a rubber vulcanization accelerator dibenzothiazyl disulfide.
In order to achieve the above purpose, the invention adopts the following technical scheme: a preparation method of a rubber vulcanization accelerator dibenzothiazyl disulfide comprises the following steps:
(1) Adding crude 2-mercaptobenzothiazole (crude M), a reducing agent and a catalyst into a pressure vessel by taking a mixed solvent of an organic solvent and water as a medium, and replacing air in the system by inert gas;
(2) Stirring and heating to a certain temperature for reaction for 1-2 h;
(3) Stirring and cooling to a certain temperature, and then replacing gas in the system by inert gas;
(4) Maintaining the temperature and adding an oxidant to perform a staged oxidation reaction;
(5) Separating and washing to obtain the high-quality dibenzothiazyl disulfide.
Preferably, the organic solvent is one or a mixture of more of benzene, toluene and xylene;
preferably, the inert gas is nitrogen;
preferably, the use amount of the organic solvent is 1-2 times of the mass of the crude M, and the use amount of the water is 5-10 times of the mass of the crude M;
preferably, the reducing agent is formic acid, and the dosage of the reducing agent is 5-10% of the mass of the crude M;
preferably, the catalyst is dichlorotris (triphenylphosphine) ruthenium, and the dosage of the catalyst is 0.1-0.5% of the mass of crude M;
preferably, the stirring and heating to a certain temperature means heating to 172-180 ℃;
preferably, the cooling to a certain temperature means that the temperature is reduced to 70-80 ℃;
preferably, the oxidant is hydrogen peroxide and sodium persulfate;
preferably, the sectional oxidation reaction is a two-stage oxidation reaction, namely, firstly adding hydrogen peroxide for oxidation, and then adding sodium persulfate for further oxidation;
preferably, the molar ratio of M to hydrogen peroxide to sodium persulfate is 1.0:0.6-0.7:0.025-0.035;
the invention has the beneficial effects that:
(1) the mixed solvent of benzene, toluene, xylene and the like and water is selected as a reaction medium, impurities in crude M are dissolved in an organic solvent, and undissolved M is dispersed in water; the dissolution reduction reaction and the separation and impurity removal under the high temperature condition are adopted, so that the solubility of byproducts in an organic phase is improved, and the use amount of organic solvents is reduced.
(2) The formic acid is used as a reducing agent, the high-efficiency catalyst is screened out, indissolvable resin byproducts and colored impurities are dissolved in an organic solvent after being subjected to transfer catalytic reduction, and meanwhile, M is not reduced due to weaker reducing capacity of the formic acid, so that complex operation steps of decoloring, adsorption and impurity removal in the existing process are avoided, the process is simpler, and additional wastes such as activated carbon and the like are not generated; the byproduct carbon dioxide after the reduction of formic acid can be directly discharged out of the system, so that the defect that inorganic salt is additionally generated when an inorganic reducing agent (such as sodium sulfite and the like) is used is avoided.
(3) Because the oxidant hydrogen peroxide and sodium persulfate are both aqueous solutions and are insoluble in organic solvents, the reaction of oxidizing M into dibenzothiazyl disulfide mainly occurs in an aqueous system, the formation of dibenzothiazyl disulfide solid is also in water, and therefore impurities dissolved in the organic solvents cannot be entrapped in the formed dibenzothiazyl disulfide solid, so that a high-quality dibenzothiazyl disulfide product with high purity, high yield and white appearance can be obtained.
(4) The method adopts two-stage oxidation, firstly, a proper excessive amount of green oxidant hydrogen peroxide is used for oxidizing most M into dibenzothiazyl disulfide, and simultaneously, a small amount of unreduced colored impurities are further oxidized into soluble substances so as to be removed; the remaining small amount of unreacted M is further and thoroughly oxidized by sodium persulfate with the oxidation capability slightly stronger than that of hydrogen peroxide, so that the high-quality dibenzothiazole disulfide with low free M is obtained, and the generation of inorganic salt byproducts is reduced and the treatment difficulty of wastewater is reduced because only a small amount of sodium persulfate is needed.
In summary, the invention prepares the high-purity dibenzothiazyl disulfide by taking crude M as a raw material and taking a mixed solvent of water and an organic solvent as a medium through transfer catalytic reduction and two-stage oxidation, wherein the purity reaches more than 99 percent, the free M is lower than 0.2 percent, and the melting point is more than or equal to 181 ℃. The method saves the refining step in the production of M while obtaining the high-purity dibenzothiazyl disulfide product, and has simple and convenient operation, thus having higher economic benefit.
Detailed Description
The invention is further illustrated by the following examples.
Example 1
In the scheme, M is hydrogen peroxide: sodium persulfate molar ratio=1:0.7:0.025, toluene usage 2 times the crude M mass, water usage 5 times the crude M mass, formic acid usage 5% of crude M, and tris (triphenylphosphine) ruthenium usage 0.1%.
37.17g of crude M (content 90%) is weighed, 74.34g of toluene, 186g of water, 1.86g of formic acid (content 88%) and 0.04g of dichlorotris (triphenylphosphine) ruthenium are added into a stainless steel high-pressure reaction kettle, air in the system is replaced by nitrogen, the temperature is raised to 172 ℃ by closed stirring, the temperature is reduced to 75 ℃ after stirring for 1h, the gas in the system is replaced by nitrogen, a condenser is opened for reflux, 47.6g of hydrogen peroxide (mass content 10%) is slowly added into the reaction kettle for about 6h, then 23.81g of sodium persulfate aqueous solution (mass content 5%) is continuously added, and the reaction kettle is finished for about 2h. After the addition, the stirring is closed, the mixture is filtered, the filter cake is washed 1 time by toluene and then is dried for 2 times, so that 32.31g of white dibenzothiazyl disulfide powder is obtained, the purity of HPLC detection is 99.34%, the free M is 0.04%, the melting point is 182.6 ℃, and the yield is 97.17%.
Example 2
This example was carried out on the basis of example 1, with the formic acid content increasing to 10% of the crude M, the remainder not becoming.
37.17g of crude M (content 90%) is weighed, 74.34g of toluene, 186g of water, 3.72g of formic acid (content 88%) and 0.04g of dichlorotris (triphenylphosphine) ruthenium are added into a stainless steel high-pressure reaction kettle, air in the system is replaced by nitrogen, the temperature is raised to 172 ℃ by closed stirring, the temperature is reduced to 75 ℃ after stirring for 1h, the gas in the system is replaced by nitrogen, a condenser is opened for reflux, 47.6g of hydrogen peroxide (mass content 10%) is slowly added into the reaction kettle for about 6h, then 23.81g of sodium persulfate aqueous solution (mass content 5%) is continuously added, and the reaction kettle is finished for about 2h. After the addition, the stirring is closed, the white dibenzothiazyl disulfide powder is obtained by filtering, washing a filter cake with toluene for 1 time, washing with water for 2 times and drying, wherein the purity of the white dibenzothiazyl disulfide powder is 99.29 g, the free M is 0.05% by HPLC detection, the melting point is 182.7 ℃, and the yield is 97.11%.
On the basis of the example 1, the consumption of the reducing agent is increased, the purity of the dibenzothiazyl disulfide is improved, and the yield is reduced, because the reduction reaction of insoluble impurities in the organic solvent is more thoroughly carried out and the removal is more thoroughly carried out.
Example 3
This example was carried out under the conditions that the amount of sodium persulfate was increased to 0.035 based on example 1 and that the other conditions were kept unchanged.
37.17g of crude M (content 90%) is weighed, 74.34g of toluene, 186g of water, 1.86g of formic acid (content 88%) and 0.04g of dichlorotris (triphenylphosphine) ruthenium are added into a stainless steel high-pressure reaction kettle, air in the system is replaced by nitrogen, the temperature is raised to 172 ℃ by closed stirring, the temperature is reduced to 75 ℃ after stirring for 1h, the gas in the system is replaced by nitrogen, a condenser is opened for reflux, 47.6g of hydrogen peroxide (mass content 10%) is slowly added into the reaction kettle for about 6h, then 33.33g of sodium persulfate aqueous solution (mass content 5%) is continuously added, and the addition is completed for about 2h. After the addition, the stirring is closed, the white dibenzothiazyl disulfide powder is obtained by filtering, washing a filter cake with toluene for 1 time, washing with water for 2 times and drying, wherein the purity of the white dibenzothiazyl disulfide powder is 99.58 g, the free M is 0.02 percent, the melting point is 183.5 ℃, and the yield is 97.99 percent.
On the basis of the embodiment 1, the dosage of the sodium peroxodisulphate is increased, and the yield, the purity and the melting point are greatly improved and the content of free M is further reduced because the organic solvent and the undissolved M are more oxidized into products.
Example 4
This example was performed under the same conditions as in example 1, except that toluene was changed to xylene.
37.17g of crude M (content 90%) is weighed, 74.34g of dimethylbenzene, 186g of water, 1.86g of formic acid (content 88%) and 0.04g of dichlorotris (triphenylphosphine) ruthenium are added into a stainless steel high-pressure reaction kettle, air in the system is replaced by nitrogen, the temperature is raised to 172 ℃ by closed stirring, the temperature is reduced to 75 ℃ after stirring for 1h, the gas in the system is replaced by nitrogen, a condenser is opened for reflux, 47.6g of hydrogen peroxide (mass content 10%) is slowly added into the reaction kettle for about 6h, then 23.81g of sodium persulfate aqueous solution (mass content 5%) is continuously added, and the addition is completed for about 2h. After the addition, the stirring is closed, the white dibenzothiazyl disulfide powder is obtained by filtering, washing the filter cake with xylene for 1 time, washing with water for 2 times and drying, wherein the purity of the white dibenzothiazyl disulfide powder is 99.21 percent by HPLC detection, the free M is 0.05 percent, the melting point is 181.9 ℃, and the yield is 98.07 percent.
In example 1, toluene was changed to xylene, and the purity and melting point of dibenzothiazyl disulfide were slightly lowered, but the yield was improved.
Example 5
This example was carried out on the basis of example 1, with the amount of ruthenium dichlorotris (triphenylphosphine) catalyst being increased to 0.5% of the mass of the crude M, the other conditions remaining unchanged.
37.17g of crude M (content 90%) is weighed, 74.34g of toluene, 186g of water, 1.86g of formic acid (content 88%) and 0.04g of dichlorotris (triphenylphosphine) ruthenium are added into a stainless steel high-pressure reaction kettle, air in the system is replaced by nitrogen, the temperature is raised to 172 ℃ by closed stirring, the temperature is reduced to 75 ℃ after stirring for 1h, the gas in the system is replaced by nitrogen, a condenser is opened for reflux, 47.6g of hydrogen peroxide (mass content 10%) is slowly added into the reaction kettle for about 6h, then 23.81g of sodium persulfate aqueous solution (mass content 5%) is continuously added, and the reaction kettle is finished for about 2h. After the addition, the stirring is closed, the white dibenzothiazyl disulfide powder is obtained by filtering, washing a filter cake with toluene for 1 time, washing with water for 2 times and drying, wherein the purity of the white dibenzothiazyl disulfide powder is 99.27 g, the free M is 0.03 percent, the melting point is 183.2 ℃, and the yield is 97.05 percent.
On the basis of example 1, the purity and melting point of dibenzothiazyl disulfide are slightly improved by increasing the catalyst dosage, but the yield is reduced.
Comparative example 1
This example was carried out without adding formic acid or catalyst on the basis of example 1, while the other was kept unchanged.
37.17g of crude M (content of 90%) is weighed, 74.34g of toluene and 186g of water are added into a stainless steel high-pressure reaction kettle, air in the system is replaced by nitrogen, the temperature is raised to 172 ℃ by closed stirring, the temperature is reduced to 75 ℃ after stirring reaction is carried out for 1h, the gas in the system is replaced by nitrogen, a condenser is opened for reflux, 47.6g of hydrogen peroxide (mass content of 10%) is slowly added into the reaction kettle for about 6h, then 23.81g of sodium persulfate aqueous solution (mass content of 5%) is continuously added, and the addition is completed for about 2h. After the addition, the stirring is closed, the mixture is filtered, the filter cake is washed 1 time by toluene and then is dried for 2 times, and 34.65g of yellow dibenzothiazyl disulfide powder is obtained, the purity of HPLC detection is 98.56%, the free M is 0.02%, the melting point is 176.1 ℃, and the yield is 97.78%.
Experiments show that the colored impurities in the crude product M are difficult to dissolve completely without transfer catalytic reduction reaction, so that the product purity, the melting point and the appearance are lower, and the yield is improved, but the impurity removal is insufficient and the impurity content is higher.
Comparative example 2
37.17g of crude M (content 90%) is weighed, 74.34g of toluene, 186g of water, 1.86g of formic acid (content 88%) and 0.04g of dichlorotris (triphenylphosphine) ruthenium are added into a stainless steel high-pressure reaction kettle, air in the system is replaced by nitrogen, the temperature is raised to 160 ℃ by closed stirring, the temperature is reduced to 75 ℃ after stirring for 1h, the gas in the system is replaced by nitrogen, a condenser is opened for reflux, 47.6g of hydrogen peroxide (mass content 10%) is slowly added into the reaction kettle for about 6h, then 23.81g of sodium persulfate aqueous solution (mass content 5%) is continuously added, and the reaction kettle is finished for about 2h. After the addition, the stirring is closed, the mixture is filtered, the filter cake is washed 1 time by toluene and then is dried for 2 times, thus obtaining 32.35g of yellow dibenzothiazyl disulfide powder, the purity of HPLC detection is 99.11%, the free M is 0.04%, the melting point is 182.0 ℃, and the yield is 97.29%.
Experiments show that reducing the catalytic reduction reaction temperature to 160 ℃ reduces the reduction capacity of formic acid, and colored impurities in the crude product M are difficult to remove, so that the product has low purity, melting point and poor appearance.
Comparative example 3
37.17g of crude M (content 90%) is weighed, 74.34g of toluene, 186g of water, 1.86g of formic acid (content 88%) and 0.04g of dichlorotris (triphenylphosphine) ruthenium are added into a stainless steel high-pressure reaction kettle, air in the system is replaced by nitrogen, the temperature is raised to 190 ℃ by closed stirring, the temperature is reduced to 75 ℃ after stirring for 1h, the gas in the system is replaced by nitrogen, a condenser is opened for reflux, 47.6g of hydrogen peroxide (mass content 10%) is slowly added into the reaction kettle for about 6h, then 23.81g of sodium persulfate aqueous solution (mass content 5%) is continuously added, and the reaction kettle is finished for about 2h. After the addition, the stirring is closed, the mixture is filtered, the filter cake is washed 1 time by toluene and then is dried for 2 times, thus obtaining 32.27g of white dibenzothiazyl disulfide powder, the purity of the white dibenzothiazyl disulfide powder is 99.11% by HPLC detection, the free M is 0.14%, the melting point is 182.0 ℃, and the yield is 97.05%.
32.31g, 99.34% purity by HPLC, 0.04% free M, melting point 182.6℃and yield 97.17%.
Experiments show that the catalytic reduction reaction temperature is increased to 190 ℃, the formic acid reduction capability is too strong, the purity melting point is reduced, and the content of free M is increased. This is because the reducing property is too strong, resulting in the reduction of part M, and thus other poorly soluble impurities are formed at the time of the subsequent oxidation, resulting in the reduction of the purity of dibenzothiazyl disulfide, while the amount of oxidizing agent is insufficient to completely oxidize M due to the consumption of part of the oxidizing agent by the impurities.
Comparative example 4
This example is based on example 1, with formic acid and catalyst replaced by sodium borohydride.
37.17g of crude M (content 90%) is weighed, 74.34g of toluene, 186g of water and 1.86g of sodium borohydride are added into a stainless steel high-pressure reaction kettle, air in the system is replaced by nitrogen, the temperature is raised to 172 ℃ by closed stirring, the temperature is reduced to 75 ℃ after stirring reaction is carried out for 1h, the gas in the system is replaced by nitrogen, a condenser is opened for reflux, 47.6g of hydrogen peroxide (mass content 10%) is slowly added into the reaction kettle for about 6h, and then 23.81g of sodium persulfate aqueous solution (mass content 5%) is continuously added for about 2h. After the addition, the stirring is closed, the mixture is filtered, the filter cake is washed 1 time by toluene and then is dried for 2 times, thus obtaining 32.35g of white dibenzothiazyl disulfide powder, the purity of HPLC detection is 97.24%, the free M is 1.06%, the melting point is 175.3 ℃, and the yield is 97.29%.
The results show that the sodium borohydride with stronger reducibility is used for reduction, the purity melting point is reduced more, and the content of free M is increased more.
Comparative example 5
37.17g of crude M (content 90%) is weighed, 74.34g of toluene, 186g of water, 1.86g of formic acid (content 88%) and 0.04g of dichlorotris (triphenylphosphine) ruthenium are added into a stainless steel high-pressure reaction kettle, air in the system is replaced by nitrogen, the temperature is raised to 172 ℃ by closed stirring, the temperature is lowered to 75 ℃ after stirring reaction for 1h, gas in the system is replaced by nitrogen, a condenser is opened for reflux, 47.6g of hydrogen peroxide (mass content 10%) is slowly added into the reaction kettle for about 6h, and the heat preservation reaction is continued for 2h. The stirring is closed, the filtration and the toluene washing of the filter cake are carried out for 1 time, then the water washing is carried out for 2 times, and the drying is carried out, thus obtaining 32.56g of white dibenzothiazyl disulfide powder, the purity of HPLC detection is 94.86%, the free M is 5.03%, the melting point is 168.8 ℃, and the yield is 101.31%.
Experiments show that M is difficult to completely oxidize into DM without performing a two-stage sodium persulfate oxidation step, so that the purity and the melting point of the product are lower, and the content of free M is higher.
Comparative example 6
37.17g of crude M (content 90%) is weighed, 260.34g of water, 1.86g of formic acid (content 88%) and 0.04g of dichloro tri (triphenylphosphine) ruthenium are added into a stainless steel high-pressure reaction kettle, air in the system is replaced by nitrogen, the temperature is raised to 172 ℃ by closed stirring, the temperature is reduced to 75 ℃ after stirring reaction is carried out for 1h, gas in the system is replaced by nitrogen, a condenser is opened for reflux, 47.6g of hydrogen peroxide (content 10% by mass) is slowly added into the reaction kettle for about 6h, and then 23.81g of sodium persulfate aqueous solution (content 5% by mass) is continuously added for about 2h. After the addition, the stirring is closed, the filtration, the filter cake washing for 2 times and the drying are carried out, thus obtaining 35.99g of yellow-green dibenzothiazyl disulfide powder, the purity of which is 89.62 percent by HPLC detection, the free M is 10.26 percent, the melting point is 146.7 ℃, and the yield is 108.23 percent.
The method is characterized in that the method is directly synthesized by using crude M without using an organic solvent, a large amount of impurities in the crude M remain in the product, and meanwhile, the M cannot be completely oxidized due to the influence of the impurities, so that the appearance, the purity and the melting point of the dibenzothiazyl disulfide are greatly reduced.
Comparative example 7
37.17g of crude M (content 90%) is weighed, 260.34g of toluene, 1.86g of formic acid (content 88%) and 0.04g of dichloro tri (triphenylphosphine) ruthenium are added into a stainless steel high-pressure reaction kettle, air in the system is replaced by nitrogen, the temperature is raised to 172 ℃ by closed stirring, the temperature is reduced to 75 ℃ after stirring for 1h, the gas in the system is replaced by nitrogen, a condenser is opened for reflux, 47.6g of hydrogen peroxide (content 10%) is slowly added into the reaction kettle for about 6h, and then 23.81g of sodium persulfate aqueous solution (content 5%) is continuously added for about 2h. After the addition, the stirring is closed, the mixture is filtered, the filter cake is washed 1 time by toluene and then is dried for 2 times, thus obtaining 32.31g of white dibenzothiazyl disulfide powder, the purity of HPLC detection is 99.04%, the free M is 0.03%, the melting point is 180.1 ℃, and the yield is 95.07%.
Although toluene is used as a solvent only at the beginning of the reaction, since hydrogen peroxide and sodium persulfate are both aqueous solutions, the amount of water is reduced and the amount of toluene is increased, and a small amount of dibenzothiazyl disulfide is dissolved in toluene, so that the yield is reduced, and the purity of dibenzothiazyl disulfide is reduced due to the reduction of the amount of water.
Comparative example 8
37.17g of crude M (content of 90%) is weighed, 74.34g of toluene, 186g of water, 1.86g of formic acid (content of 88%) and 0.04g of dichlorotris (triphenylphosphine) ruthenium are added into a stainless steel high-pressure reaction kettle, air in the system is replaced by nitrogen, the temperature is raised to 172 ℃ by closed stirring, the temperature is reduced to 90 ℃ after stirring for 1h, the gas in the system is replaced by nitrogen, a condenser is opened for reflux, 47.6g of hydrogen peroxide (mass content of 10%) is slowly added into the reaction kettle for about 6h, then 23.81g of sodium persulfate aqueous solution (mass content of 5%) is continuously added, and the reaction kettle is finished for about 2h. After the addition, the stirring is closed, the mixture is filtered, the filter cake is washed 1 time by toluene and then is washed 2 times by water, the mixture is dried to obtain 32.42g of light yellow dibenzothiazyl disulfide powder, the purity of the light yellow dibenzothiazyl disulfide powder detected by HPLC is 98.89%, the free M is 0.76%, the melting point is 179.7 ℃, and the yield is 97.50%.
The oxidation temperature is increased to 90 ℃, and a small amount of DM is peroxidized due to the fact that the oxidation capability of sodium persulfate is increased by the temperature, so that the appearance of dibenzothiazyl disulfide is yellowing, and meanwhile, the use amount of an oxidant is slightly insufficient due to the fact that the decomposition speed of hydrogen peroxide is increased due to the fact that the temperature is too high, so that the content of free M is increased.
The foregoing detailed description is provided to illustrate the present invention and not to limit the invention, and any modifications and changes made to the present invention within the spirit of the present invention and the scope of the appended claims fall within the scope of the present invention.
Claims (1)
1. The preparation method of the dibenzothiazyl disulfide serving as the rubber vulcanization accelerator is characterized by comprising the following steps of:
weighing 37.17g of crude 2-mercaptobenzothiazole with the content of 90%, 74.34g of toluene, 186g of water, 1.86g of formic acid with the content of 88%, 0.04g of tris (triphenylphosphine) ruthenium dichloride, adding into a stainless steel high-pressure reaction kettle, replacing air in the system with nitrogen, stirring and heating to 172 ℃, cooling to 75 ℃ after stirring and reacting for 1h, replacing gas in the system with nitrogen, opening a condenser for reflux, slowly adding 47.6g of hydrogen peroxide with the mass content of 10% into the reaction kettle for 6h, and then continuously adding 33.33g of sodium persulfate aqueous solution with the mass content of 5% into the reaction kettle for 2h; after the addition, the stirring is closed, the filtration and the toluene washing of a filter cake are carried out for 1 time, the water washing is carried out for 2 times, the white dibenzothiazyl disulfide powder is obtained by drying, 32.58g, the purity of HPLC detection is 99.52%, the free 2-mercaptobenzothiazole is 0.02%, the melting point is 183.5 ℃, and the yield is 97.99%.
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| CN101693701A (en) * | 2009-10-21 | 2010-04-14 | 山东阳谷华泰化工股份有限公司 | Purification process for vulcanization accelerator 2-mercaptobenzothiazole |
| CN103193732A (en) * | 2013-04-25 | 2013-07-10 | 宝月（天津）环保工程有限公司 | Preparation method of rubber vulcanization accelerator DM |
| CN104230843A (en) * | 2014-08-29 | 2014-12-24 | 山东海迈新材料有限公司 | Process for sectional oxosynthesis of DM (dibenzothiazyl disulfide) |
| CN108610303A (en) * | 2018-08-08 | 2018-10-02 | 山东金城医药化工有限公司 | The synthetic method of dibenzothiazyl disulfide |
| CN111620836A (en) * | 2020-06-23 | 2020-09-04 | 河南省化工研究所有限责任公司 | Method for refining 2-mercaptobenzothiazole |
| CN112625002A (en) * | 2019-09-24 | 2021-04-09 | 河北合佳医药科技集团股份有限公司 | Preparation method of pharmaceutical-grade dibenzothiazyl disulfide |
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101693701A (en) * | 2009-10-21 | 2010-04-14 | 山东阳谷华泰化工股份有限公司 | Purification process for vulcanization accelerator 2-mercaptobenzothiazole |
| CN103193732A (en) * | 2013-04-25 | 2013-07-10 | 宝月（天津）环保工程有限公司 | Preparation method of rubber vulcanization accelerator DM |
| CN104230843A (en) * | 2014-08-29 | 2014-12-24 | 山东海迈新材料有限公司 | Process for sectional oxosynthesis of DM (dibenzothiazyl disulfide) |
| CN108610303A (en) * | 2018-08-08 | 2018-10-02 | 山东金城医药化工有限公司 | The synthetic method of dibenzothiazyl disulfide |
| CN112625002A (en) * | 2019-09-24 | 2021-04-09 | 河北合佳医药科技集团股份有限公司 | Preparation method of pharmaceutical-grade dibenzothiazyl disulfide |
| CN111620836A (en) * | 2020-06-23 | 2020-09-04 | 河南省化工研究所有限责任公司 | Method for refining 2-mercaptobenzothiazole |
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