CN108947922B - Preparation method of 1-phenyl-5-mercapto tetrazole - Google Patents
Preparation method of 1-phenyl-5-mercapto tetrazole Download PDFInfo
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Abstract
The invention provides a preparation method of 1-phenyl-5-mercapto tetrazole. According to the invention, sodium azide and phenyl isothiocyanate are used as reaction raw materials for preparing 1-phenyl-5-mercapto tetrazole, and the reaction temperature is controlled to be 90-95 ℃, the reaction time is 110-130 min, so that the sodium azide and the phenyl isothiocyanate can be fully subjected to an azide reaction under mild reaction conditions without using a catalyst; meanwhile, the preparation method provided by the invention is simple to operate, does not need complex production equipment, and has small environmental pollution in the production process; in addition, the preparation method provided by the invention is simple in post-treatment operation, low in production cost and easy to realize large-scale industrial production. The results of the embodiment show that when the method provided by the invention is used for large-scale industrial production, the yield of the target product 1-phenyl-5-mercapto tetrazole can reach 94.8%, and the actual production needs can be met.
Description
Technical Field
The invention relates to the technical field of organic synthesis, in particular to a preparation method of 1-phenyl-5-mercapto tetrazole.
Background
The statin medicine is a hydroxymethyl glutaryl coenzyme A (HMG-CoA) reductase inhibitor, and has the functions of regulating blood fat, resisting oxidation, resisting inflammation, regulating vascular endothelial function, inhibiting thrombosis and other important non-lipid-lowering regulation functions. Wherein, 1-phenyl-5-mercapto tetrazole (PMT) is an important intermediate for preparing statins. In addition, PMT may be used as photographic antifogging agent, electroplating additive, photosensitive material stabilizer, etc.
In the prior art, phenyl isothiocyanate reacts with hydrazine hydrate to generate 1-phenyl-2-thiosemicarbazide, the 1-phenyl-2-thiosemicarbazide is cyclized under the action of nitrous acid, and then the cyclized product reacts with sodium carbonate to be rearranged and synthesized into PMT (synthesis of 1-substituted phenyl-5-mercapto tetrazole, such as Lin et al, photosensitive material, 1984, stage 01); however, this method requires many kinds of reagents, and has many reaction steps and complicated operation.
Disclosure of Invention
The invention aims to provide a preparation method of 1-phenyl-5-mercapto tetrazole, the preparation method provided by the invention is simple to operate, the reaction condition is mild, a catalyst is not required, the yield of the prepared 1-phenyl-5-mercapto tetrazole is high, and large-scale industrial production is easy to realize.
In order to achieve the above object, the present invention provides the following technical solutions:
the invention provides a preparation method of 1-phenyl-5-mercapto tetrazole, which comprises the following steps:
mixing a sodium azide aqueous solution with phenyl isothiocyanate at the temperature of 90-95 ℃, and then carrying out heat preservation for carrying out an azide reaction for 110-130 min to obtain an azide reaction product feed liquid;
and mixing the nitridized reaction product liquid with water, adjusting the pH value of the obtained material to 3.0-5.0 by using hydrochloric acid, and carrying out acidification treatment for 50-70 min to obtain the 1-phenyl-5-mercapto tetrazole.
Preferably, the mass content of sodium azide in the sodium azide aqueous solution is 8-12%.
Preferably, the mass ratio of sodium azide to phenyl isothiocyanate in the sodium azide aqueous solution is 1: (2.00-2.15).
Preferably, the mixing of the sodium azide aqueous solution and the phenyl isothiocyanate is to drop the phenyl isothiocyanate into the sodium azide aqueous solution.
Preferably, the azide reaction further comprises, after completion:
and mixing the system obtained by the azide reaction with active carbon, carrying out decolorization treatment, and filtering to obtain azide reaction product feed liquid.
Preferably, the mass ratio of the activated carbon to the phenyl isothiocyanate is 0.1: (2.05-2.15).
Preferably, the mass ratio of the azide reaction product liquid to water is (12.5-13.5): 3.
preferably, the mass concentration of the hydrochloric acid is more than or equal to 31 percent.
Preferably, the acidification treatment further comprises:
and carrying out solid-liquid separation on the obtained system, and sequentially washing and drying the obtained solid material to obtain the 1-phenyl-5-mercapto tetrazole.
The invention provides a preparation method of 1-phenyl-5-mercapto tetrazole, which comprises the steps of mixing sodium azide aqueous solution and phenyl isothiocyanate at the temperature of 90-95 ℃, and then carrying out heat preservation for an azide reaction for 110-130 min to obtain azide reaction product feed liquid; and mixing the nitridized reaction product liquid with water, adjusting the pH value of the obtained material to 3.0-5.0 by using hydrochloric acid, and carrying out acidification treatment for 50-70 min to obtain the 1-phenyl-5-mercapto tetrazole. According to the invention, sodium azide and phenyl isothiocyanate are used as reaction raw materials for preparing 1-phenyl-5-mercapto tetrazole, and the reaction temperature is controlled to be 90-95 ℃, the reaction time is 110-130 min, so that the sodium azide and the phenyl isothiocyanate can be fully subjected to an azide reaction under mild reaction conditions without using a catalyst; meanwhile, the preparation method provided by the invention is simple to operate, does not need complex production equipment, and has small environmental pollution in the production process; in addition, the preparation method provided by the invention is simple in post-treatment operation, low in production cost and easy to realize large-scale industrial production. The results of the embodiment show that when the method provided by the invention is used for large-scale industrial production, the yield of the target product 1-phenyl-5-mercapto tetrazole can reach 94.8%, and the actual production needs can be met.
Detailed Description
The invention provides a preparation method of 1-phenyl-5-mercapto tetrazole, which comprises the following steps:
mixing a sodium azide aqueous solution with phenyl isothiocyanate at the temperature of 90-95 ℃, and then carrying out heat preservation for carrying out an azide reaction for 110-130 min to obtain an azide reaction product feed liquid;
and mixing the nitridized reaction product liquid with water, adjusting the pH value of the obtained material to 3.0-5.0 by using hydrochloric acid, and carrying out acidification treatment for 50-70 min to obtain the 1-phenyl-5-mercapto tetrazole.
According to the invention, at the temperature of 90-95 ℃, sodium azide aqueous solution and phenyl isothiocyanate are mixed and then subjected to heat preservation for azide reaction for 110-130 min, so as to obtain azide reaction product liquid. In the invention, the mass content of sodium azide in the sodium azide aqueous solution is preferably 8-12%, and more preferably 9-10%. In the present invention, the water in the aqueous sodium azide solution is preferably purified water.
In the present invention, the mass ratio of sodium azide to phenyl isothiocyanate in the sodium azide aqueous solution is preferably 1: (2.00-2.15), more preferably 1: (2.03-2.10), most preferably 1: (2.05-2.08). In the invention, the phenylisothiocyanate is preferably prepared by a method disclosed in Chinese patent with the publication number of CN 103755612A. In the invention, the quality of the phenyl isothiocyanate serving as a reaction raw material for preparing the 1-phenyl-5-mercapto tetrazole has an important influence on the yield and the purity of the finally prepared 1-phenyl-5-mercapto tetrazole, and if the impurities in the phenyl isothiocyanate are excessive, a side reaction exists in the nitridizing reaction process, so that the yield and the purity of the 1-phenyl-5-mercapto tetrazole are reduced.
In the present invention, the sodium azide aqueous solution and phenyl isothiocyanate are mixed, and the phenyl isothiocyanate is preferably added dropwise to the sodium azide aqueous solution. The dropping rate is not particularly limited in the present invention, and the uniform dropping can be performed at a dropping rate well known to those skilled in the art according to the actual production scale. According to the invention, phenyl isothiocyanate is added into the sodium azide aqueous solution in a dropwise manner, so as to ensure that the phenyl isothiocyanate and the sodium azide aqueous solution can be fully reacted.
In the invention, the temperature of the azide reaction is 90-95 ℃, preferably 91-94 ℃; in the embodiment of the invention, sodium azide aqueous solution is heated to 90-95 ℃, and then phenyl isothiocyanate is dropwise added to carry out azide reaction. In the invention, the time of the azide reaction is preferably 110-130 min, and more preferably 120 min. In the invention, the nitridization reaction is started by dripping the phenyl isothiocyanate into the sodium azide aqueous solution, and the nitridization reaction time is calculated after the dripping of the phenyl isothiocyanate is finished. In the present invention, the azidation reaction is preferably performed under stirring conditions; the stirring rate is not particularly limited in the present invention, and a stirring rate known to those skilled in the art may be used.
In the invention, the phenyl isothiocyanate and sodium azide are subjected to azide reaction to generate 1-phenyl-5-mercapto tetrazole sodium, and subsequent acidification treatment is carried out to finally obtain the 1-phenyl-5-mercapto tetrazole. In the invention, the selection of the temperature and time of the azidation has important influence on the reaction degree of the azidation and the yield of the target product 1-phenyl-5-mercapto tetrazole, the temperature of the azidation is too low, the reaction between the phenyl isothiocyanate and the sodium azide is insufficient, the reaction time is prolonged, and the product yield and the reaction efficiency are reduced; the temperature of the azide reaction is too high, so that impurities in the raw materials are easy to generate side reactions, and the moisture in the reaction system is evaporated too fast, so that the smooth proceeding of the azide reaction is influenced.
In the present invention, it is preferable that the azide reaction further comprises:
and mixing the system obtained by the azide reaction with active carbon, carrying out decolorization treatment, and filtering to obtain azide reaction product feed liquid.
In the present invention, the mass ratio of the activated carbon to the phenyl isothiocyanate is preferably 0.1: (2.00-2.15), more preferably 0.1: (2.03-2.10), most preferably 0.1: (2.05-2.08). In the present invention, the time for the decoloring treatment is preferably 25 to 35min, and more preferably 30 min. In the present invention, the decoloring treatment is preferably performed under stirring conditions; the stirring rate is not particularly limited in the present invention, and a stirring rate known to those skilled in the art may be used. In the present invention, the decoloring treatment is performed to remove colored impurities present in the reaction raw materials and sulfur generated during the azidation reaction.
After the azide reaction product liquid is obtained, the azide reaction product liquid is directly mixed with water without other post-treatment, the pH value of the obtained material is adjusted to be 3.0-5.0 by hydrochloric acid, and acidification treatment is carried out for 50-70 min to obtain the 1-phenyl-5-mercapto tetrazole. In the invention, the mass ratio of the azide reaction product liquid to water is preferably (12.5-13.5): 3, more preferably (12.8 to 13.2): 3, most preferably 13: 3. in the present invention, the water is preferably purified water. The invention mixes the azide reaction product feed liquid with water, and aims to dilute the azide reaction product feed liquid so as to carry out subsequent acidification treatment.
The pH value of the material obtained by mixing the azide reaction product liquid and water is adjusted to be 3.0-5.0 by hydrochloric acid, and the optimal pH value is 3.5-4.5. In the present invention, the mass concentration of the hydrochloric acid is preferably not less than 31%, and more preferably 32 to 33%. The addition amount of the hydrochloric acid is not specially limited, and the pH value of the material obtained after the material liquid of the azide reaction product is mixed with water can be adjusted to 3.0-5.0. In the invention, the hydrochloric acid is preferably added dropwise; the dropping rate is not particularly limited in the present invention, and the uniform dropping can be performed at a dropping rate well known to those skilled in the art according to the actual production scale.
In the invention, the temperature of the acidification treatment is preferably 25-30 ℃. In the invention, the time of the acidification treatment is 50-70 min, preferably 60 min; the time of the acidification treatment of the invention is calculated after the hydrochloric acid is dripped.
In the invention, in the acidification treatment process, hydrogen ions can replace sodium ions in the 1-phenyl-5-mercapto tetrazole sodium, and the target product 1-phenyl-5-mercapto tetrazole is finally prepared. According to the invention, the pH value of the reaction system is adjusted to 3.0-5.0, and then the acidification treatment is carried out, so that sodium ions in the 1-phenyl-5-mercapto tetrazole sodium can be completely replaced by hydrogen ions under mild acidic conditions, and the corrosion condition of equipment is reduced.
In the present invention, it is preferable that the acidification treatment further comprises:
and carrying out solid-liquid separation on the obtained system, and sequentially washing and drying the obtained solid material to obtain the 1-phenyl-5-mercapto tetrazole.
The solid-liquid separation mode is not particularly limited, and the solid-liquid separation mode known to those skilled in the art can be adopted to realize the separation of the solid material and the liquid material. The invention preferably realizes the solid-liquid separation by centrifugation; the present invention is not limited to the speed and time of the centrifugation, and the centrifugation technique known to those skilled in the art can be used. In the present invention, the washing is preferably water washing; the water used for the water washing is preferably purified water. In the present invention, the drying is preferably drying under reduced pressure; the present invention is not particularly limited to the specific operation steps and conditions for the reduced pressure drying, and the technical scheme of reduced pressure drying known to those skilled in the art may be adopted.
In the invention, the chemical reaction formula for preparing the 1-phenyl-5-mercapto tetrazole is as follows:
the technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
Mixing 10.0kg of purified water with 1.0kg of sodium azide to obtain a sodium azide aqueous solution, heating to 90 ℃, dropwise adding 2.0kg of phenyl isothiocyanate under the stirring condition, after the dropwise adding is finished, keeping the temperature for reaction for 2 hours, adding 0.1kg of active carbon into the obtained system, continuously stirring for 30min, and filtering to remove the active carbon to obtain a nitridize reaction product feed liquid;
mixing the azide reaction product feed liquid with 3kg of purified water, dripping 1.5kg of hydrochloric acid with the mass concentration of 31% under the stirring condition to ensure that the pH value of the obtained material is 4.8, and performing downlink acidification treatment for 60min at the temperature of 26 ℃; and centrifuging the obtained system, washing the obtained crude product by adopting 2kg of purified water, centrifuging, and drying the obtained solid material under reduced pressure to obtain 2.4kg of 1-phenyl-5-mercaptotetrazole finished product with the yield of 93.0%.
Example 2
Mixing 10.0kg of purified water with 1.0kg of sodium azide to obtain a sodium azide aqueous solution, heating to 95 ℃, dropwise adding 2.05kg of phenyl isothiocyanate under the stirring condition, keeping the temperature for reaction for 2 hours after dropwise adding, adding 0.1kg of active carbon into the obtained system, continuously stirring for 30min, and filtering to remove the active carbon to obtain a nitridized reaction product feed liquid;
mixing the azide reaction product feed liquid with 3kg of purified water, dripping 1.5kg of hydrochloric acid with the mass concentration of 31% under the stirring condition to ensure that the pH value of the obtained material is 3.5, and performing downlink acidification treatment for 60min at the temperature of 30 ℃; and centrifuging the obtained system, washing the obtained crude product by adopting 2kg of purified water, centrifuging, and drying the obtained solid material under reduced pressure to obtain 2.452kg of 1-phenyl-5-mercaptotetrazole finished product with the yield of 92.7 percent.
Example 3
Mixing 10.0kg of purified water with 1.0kg of sodium azide to obtain a sodium azide aqueous solution, heating to 93 ℃, dropwise adding 2.08kg of phenyl isothiocyanate under the stirring condition, keeping the temperature for reaction for 2 hours after dropwise adding, adding 0.1kg of activated carbon into the obtained system, continuously stirring for 30 minutes, and filtering to remove the activated carbon to obtain a nitridized reaction product feed liquid;
mixing the azide reaction product feed liquid with 3kg of purified water, dripping 1.5kg of hydrochloric acid with the mass concentration of 31% under the stirring condition to ensure that the pH value of the obtained material is 3.5, and performing downlink acidification treatment for 60min at the temperature of 27 ℃; and centrifuging the obtained system, washing the obtained crude product by adopting 2kg of purified water, centrifuging, and drying the obtained solid material under reduced pressure to obtain 2.543kg of 1-phenyl-5-mercaptotetrazole finished product with the yield of 94.8%.
Example 4
Mixing 10.0kg of purified water with 1.0kg of sodium azide to obtain a sodium azide aqueous solution, heating to 95 ℃, dropwise adding 2.10kg of phenyl isothiocyanate under the stirring condition, keeping the temperature for reaction for 2 hours after dropwise adding, adding 0.1kg of active carbon into the obtained system, continuously stirring for 30min, and filtering to remove the active carbon to obtain a nitridized reaction product feed liquid;
mixing the azide reaction product feed liquid with 3kg of purified water, dripping 1.5kg of hydrochloric acid with the mass concentration of 31% under the stirring condition to ensure that the pH value of the obtained material is 4.5, and performing downlink acidification treatment for 60min at the temperature of 30 ℃; and centrifuging the obtained system, washing the obtained crude product by adopting 2kg of purified water, centrifuging, and drying the obtained solid material under reduced pressure to obtain 2.550kg of 1-phenyl-5-mercaptotetrazole finished product with the yield of 93.0%.
Example 5
Mixing 10.0kg of purified water with 1.0kg of sodium azide to obtain a sodium azide aqueous solution, heating to 94 ℃, dropwise adding 2.15kg of phenyl isothiocyanate under the stirring condition, keeping the temperature for reaction for 2 hours after dropwise adding, adding 0.1kg of active carbon into the obtained system, continuously stirring for 30 minutes, and filtering to remove the active carbon to obtain a nitridized reaction product feed liquid;
mixing the azide reaction product feed liquid with 3kg of purified water, dripping 1.5kg of hydrochloric acid with the mass concentration of 31% under the stirring condition to ensure that the pH value of the obtained material is 4.0, and performing downlink acidification treatment for 60min at the temperature of 27 ℃; and centrifuging the obtained system, washing the obtained crude product by adopting 2kg of purified water, centrifuging, and drying the obtained solid material under reduced pressure to obtain 2.565kg of 1-phenyl-5-mercaptotetrazole finished product with the yield of 93.6 percent.
According to the embodiment, sodium azide and phenyl isothiocyanate are used as reaction raw materials for preparing 1-phenyl-5-mercapto tetrazole, and the reaction temperature is controlled to be 90-95 ℃, the reaction time is controlled to be 110-130 min, so that sufficient azide reaction of the sodium azide and the phenyl isothiocyanate can be ensured under mild reaction conditions without using a catalyst; meanwhile, the preparation method provided by the invention is simple to operate, does not need complex production equipment, and has small environmental pollution in the production process; in addition, the preparation method provided by the invention is simple in post-treatment operation, low in production cost and easy to realize large-scale industrial production. The results of the embodiment show that when the method provided by the invention is used for large-scale industrial production, the yield of the target product 1-phenyl-5-mercapto tetrazole can reach 94.8%, and the actual production needs can be met.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (3)
1. A preparation method of 1-phenyl-5-mercapto tetrazole comprises the following steps:
mixing a sodium azide aqueous solution with phenyl isothiocyanate at the temperature of 90-95 ℃, then carrying out heat preservation for carrying out an azide reaction for 110-130 min, mixing a system obtained by the azide reaction with active carbon, carrying out decolorization treatment, and filtering to obtain an azide reaction product liquid; the mass content of sodium azide in the sodium azide aqueous solution is 8-12%; the mass ratio of sodium azide to phenyl isothiocyanate in the sodium azide aqueous solution is 1: (2.00-2.15); the mass ratio of the activated carbon to the phenyl isothiocyanate is 0.1: (2.05-2.15);
mixing the azide reaction product liquid with water, adjusting the pH value of the obtained material to 3.0-5.0 by using hydrochloric acid, carrying out acidification treatment for 50-70 min, carrying out solid-liquid separation on the obtained system, and sequentially washing and drying the obtained solid material to obtain 1-phenyl-5-mercaptotetrazole; the mass ratio of the nitridization reaction product feed liquid to water is (12.5-13.5): 3.
2. the production method according to claim 1, wherein the mixing of the aqueous sodium azide solution and phenyl isothiocyanate is performed by dropwise adding the phenyl isothiocyanate to the aqueous sodium azide solution.
3. The preparation method according to claim 1, wherein the mass concentration of the hydrochloric acid is not less than 31%.
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| CN113801072A (en) * | 2021-09-30 | 2021-12-17 | 江苏阿尔法药业股份有限公司 | Method for synthesizing rosuvastatin calcium intermediate in continuous flow tubular reactor |
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