Sodium alcoholate is prepared by sodium metal added into the corresponding alcohol. It is hygroscopic white powder. It can decompose into alcohol and sodium hydroxide with water. It is widely used in organic synthesis reactions. In particular sodium ethoxide can be used as condensing agent. Sodium methanolate is a kind of common acatalyst. Because that its hygroscopicity is not as strong as sodium ethylate and its property is more stable, it is easy to control the quality when prepared.
Sodium methanolate and sodium ethylate are two kinds of sodium alcoholate commonly used in the industry. The two both can be used as condensation agent and esterifying agent (such as the condensation and esterification of ethyl acetate, acetylacetone, methyl, ethyl malonate, barbiturates, drugs amino acids, glycerol esters); pharmaceutical raw materials and reagents (barbituric acid and its derivatives, sulfonamides, vitamins, antipyrine, chloroquine, amino acids, quinacrine, phenylbutazone, etc.); dye (yellow sand, methyl violet, tartrazine, toluidine, etc.); spices (false ionone, cyclamen aldehyde, indole and the like); grease modified aspect, preparation of fatty acid ester, non-ionic surfactant and pesticides. Sodium methanolate can be used as catalyst for the transesterification of fats. Transesterification can improve grease properties, such as improving grease shape retention and ductility.
Sodium methanolate can be prepared by the reaction of methanol with metallic sodium in the laboratory. It can be prepared by the reaction of methanol with sodium hydroxide in the industry. The relevant chemical reaction formulas are as follows:
Sodium methanolate can be prepared by the reaction of methanol with metallic sodium in the laboratory.
Sodium methanolate can be prepared by the reaction of methanol with sodium hydroxide in the industry.
Flammability hazard characteristics
It decomposes into methanol and sodium hydroxide with water. It is flammable.
Solution quality reference standard
Appearance colorless to pale yellow viscous liquid
Content (total base number) 29.5%～31.0%
Sodium methoxide (NaOCH3) 28.9%～31.0%
Sodium hydroxide (NaOH) ≤0.5%
Sodium carbonate (Na2CO3) ≤0.1%
Water (H2O) ≤0.2%
A colorless cloudy white liquid consisting of sodium methylate, a solid, dissolved in methyl alcohol. Density 9.0 lb / gal. Corrosive to metals and tissue. Used to process edible fats and oils and to make other chemicals.
Solid sodium hydroxide and methanol mix at a certain proportion. After stirring the mixture to dissolve, solid impurities are removed by sedimentation and clarification. The clear liquid is pumped into the top of the dehydration reaction column, while the refined methanol vapor is added from the bottom of the tower with continuous dehydration reaction. Then the product can be obtained from tower bottom. Aqueous methanol vapor is purified from the top of the column into the distillation system, while anhydrous methanol can be used repeatedly.
Colorless amorphous fine powder. Dissolved in methanol, ethanol.
Sodium methanolate is one of alkoxides that are generated by methanol. Its chemical formula is CH3ONa. It is strong base that is commonly used in organic synthesis.
Sodium methanolate is often stored in methanol, ethanol or the like alcohol solvent. It can generate suspension when it dissolves in ether. It can decompose into methanol and sodium hydroxide with water:
CH3ONa + H2O→CH3OH + NaOH
Sodium methanolate product has two forms: solid and liquid. Solid is pure sodium methanolate. The liquid is methanol solution of sodium methanolate and the content of sodium methylate is 27.5% to 31%.
Liquid sodium methanolate is colorless or slightly yellow viscous liquid. It is sensitive to oxygen. It is flammable, explosive and easily hygroscopic. It is soluble in methanol and ethanol, and can decompose into methanol and sodium hydroxide with water. It decomposes at 126.6℃ in the air. It is not soluble in benzene and toluene. It is strong irritant and highly corrosive. Sodium methanolate can be used as condensing agent, strong alkaline catalyst and methoxy agent for the preparation of vitamin B1, vitamin A, sulfadiazine and other drugs. Few can be used in production of pesticides. It can also be used as catalyst in processing edible fats and oils (especially processing lard). It is used as analytical reagent.
Solid sodium methanolate is colorless amorphous powder. It is sensitive to oxygen, and it is flammable. It is soluble in methanol and ethanol, and can decompose into methanol and sodium hydroxide with water. It decomposes at 126.6℃ in the air. It is mainly used for the production of sulfa drugs, VB6 and VA. Sodium methylate is a kind of catalyst for organic synthesis. It can be used for the production of pesticides and oil processing industries.
Solid sodium methanolate and sodium methoxide methanol solution
Sodium methylate is a kind of mature chemical products. It has several decades of production history in China. The overall price is high in the south than in the north. Its price is 4500 yuan/T in the southwest, and 4,000 yuan/T in Shandong. Its price changed little with the increase of methanol’s price in 2004. The profit of per ton of product is 500 to 700.
SODIUM METHYLATE is a strong base. Reacts with light metals forming H2 gas, with fire and explosion hazards. Too rapid addition of sodium methylate to a mixture of chloroform and methanol initiated an uncontrolled exothermic reaction between the chloroform and the methylate that caused a violent explosion [MCA Case History 693 1961]. Sodium methoxide is incompatible with 4-chloronitrobenzene and fluorinated cyclopropenyl methyl ethers, such as perfluoromethoxycyclopropene. The reactions are vigorous and may initiate ignition [Bretherick, 1995, pg. 191].
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated.
TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.
Foam, carbon dioxide, sand
Air & Water Reactions
Highly flammable. Ignites in moist air [Wischmeyer 1966]. Reacts with water to produce a mixed solution of sodium hydroxide and methyl alcohol.
In organic syntheses.
Sodium process for producing sodium methylate
Sodium metal and methanol as raw materials, using intermittent production process to produce methanol solution of sodium methylate. The reaction is as follows:
2CH3OH + 2Na→2CH3ONa + H2↑
The production process is mainly divided into four parts:
1. Feeding step. Industrial methanol is pumped into methanol metering tank. 120kg of sodium metal is added into the reaction kettle.
2. Nitrogen substitution step. Close feed valve and vent valve. Purged with nitrogen into the reactor so that the index reached 0.1MPa. Open vent valve to remove the pressure, and repeat three times under reflux. The vent valve remains open to continue introducing nitrogen.
3. Reaction step. The cooling water is fed to the condenser. Methanol is immediately added to the methanol tank (note methanol addition rate). Nitrogen is stopped after 5~10min. Methanol is continuously added. 820kg of methanol is added in 2~3h and then the feed valve is closed. The reaction is continued for 2~3h until the reaction mixture has no bubbles.
4. Reconciliation step. The product is added into the harmonic tank. Sample and analysis. Reconcile to the desired concentration and barrels.
Soda process for producing sodium methylate
Sodium methylate is prepared by the reaction of methanol with sodium hydroxide for soda method. Their reaction is as follows:
CH3OH + NaOH→CH3ONa + H2O
1. The preparation of methanol lye
Crush the solid sodium hydroxide. Then add it into melting pot base containing methanol (99.8%) in proportion. Start circulating pump, and dissolve the sodium hydroxide below 70℃. When its content is 20% to 23%, cool down to 40℃ and inject into the settling tank. Stand 12h and spare.
2. The preparation of sodium methylate
Pass into the steam to the vaporization pot and reaction tower mezzanine. Heat it and control the temperature at 85~100℃. Add anhydrous methanol to vaporization pot at the flow rate of 180L/h. Meanwhile add methanol lye in the top of the reaction tower at the flow rate of 25kg/h. Methanol gas containing 2% of water produced by the reaction from the reaction distill the reaction tower overhead into the purification distillation column to remove water. Then it becomes absolute methanol recycling. Control the temperature of reaction bottoms (i.e. vaporization pot) at 65~70℃, and check the bottoms. When containing 27%~31% Sodium methanolate, 1% or less of the free base, products are obtained. The yield is 86% (as sodium hydroxide).
Fixed consumption of the process is as follows: methanol (95%) 973kg/t, sodium hydroxide (99.5%) 209kg/t.
The above information is edited by the chemicalbook of Ge Qian.
Used in nonaqueous titrations.
It behaves in the same way as sodium ethoxide. It is hygroscopic and is hydrolysed by moist air to NaOH and MeOH. Material that has been kept under N2 should be used. If erratic results are obtained, even with recently purchased NaOMe, it should be freshly prepared thus: Clean Na (37g) cut in 1-3g pieces is added in small portions to stirred MeOH (800mL) in a 2L three-necked flask equipped with a stirrer and a condenser with a drying tube. After all the Na has dissolved, the MeOH is removed by distillation under vacuum, and the residual NaOMe is dried by heating at 150o under vacuum and kept under dry N2 [Burness Org Synth 39 51 1959]. [Beilstein 1 IV 1227.]
Explosive hazardous characteristics
Its hydrolysates caustic is corrosive to skin and cornea.
1. Xylene (water content < 0.05) and metallic sodium are added into reaction vessel. Heat the reaction vessel to 130～140℃, keep for 1h and stop heating. After rapid stirring for 1h, use cooling water to 50℃. Then start to dropwise add anhydrous methanol (water content < 0.1%), and appropriately add dry xylene. The dropping rate depends on the flow rate of methanol and the release of hydrogen. After the dropwise addition finishes, heat it under reflux for 4h and cool to room temperature to obtain sodium methanolate slurry. Xylene can be recovered by vacuum distillation and then dried in vacuo for 4h. Sodium methanolate can be obtained by nitrogen cooling. The yield is over 90%. Sodium methanolate can also be prepared by the continuous reaction and dehydration of sodium hydroxide with methanol at 85～100℃.
2. It can be obtained by the reaction of sodium hydroxide and methanol in benzene.
The comparison soda process with sodium process
The content of methanol alkaline get by sodium method is higher, more reliable and stable than alkaline method. And the content of free alkali is low. Sodium methylate prepared by sodium method can take off a lot of alcohol and other impurities from sodium in the reaction. The content of Na2CO3 in sodium method is lower than in alkaline method, which can improve product quality and yield of the users.
Ventilated and dry low-temperature treasury. It should be stored separately from acids and oxidizing agents.
How to separate solid sodium hydroxide and sodium methylate
1. Dissolved in water (sodium alcoholate reacts violently with water to generate alcohol and sodium hydroxide)
2. Distillation (separate alcohol)
3. Evaporation (separate sodium hydroxide)
4. Try to dry alcohol to anhydrous state (repeated distillation)
5. Add sodium to generate sodium alcohol
6. Distill alcohol to get solid alcohol sodium. (It should be avoided being exposed to the air when distilling. If it is exposed to the air or it is taken down before drying up and cooling, the state of alcohol sodium that is separated out is not well. The good one is white. if not, it will be tan is. But it doesn’t have any great impact. It is easy to be prepared.)
It can react with oxygen and carbon dioxide. It decomposes in water. Sodium test of the solution (IT-28) is positive.
Take 0.1m1 5% sulfuric acid and 0.2ml potassium permanganate solution (TS-193), and add 1 drop of 1% aqueous solution of the sample. After placing 5min, add 0.2ml 25% sodium sulfite solution and 3ml sulfate. Then add 0.2ml chromium changed acid solution (TS-l66). The solution is amaranth to purple.
1. It can be used as alkaline condensing agent and catalyst in organic synthesis. It can be used to synthesize perfumes, dyes and the like. It is also the raw material of vitamin B1, A and sulfadiazine.
2. It can be used as condensing agent in organic synthesis and catalyst in edible oil process. It is also the important raw material to synthesize sulfadiazine, sulfamethoxazole, sulfa synergist and the like.
3. It is the main raw material used for medicine, pesticide. It is also used in dyes and chemical fiber industry.
4. Fatty transesterification catalyst. It can change the fat structure so that it is suitable for margarine. It must be removed in the final food.
5. It is mainly used as condensing agent, strong alkaline catalyst and methoxy agent. It can be used for the preparation of vitamin B1 and A, sulfadiazine and other drugs. And little can be used in the production of pesticides. It can also be used as the catalyst for processing edible fats and oils (especially processing lard). It can also be used as analytical reagent.
6. It is widely used in perfumes, dyes and other industries. It is mainly used as condensing agent, strong alkaline catalyst and methoxy agent for the preparation of vitamin B1 and A, sulfadiazine and other drugs. Little can be used in the production of pesticides. It can also be used as the catalyst for processing edible fats and oils (especially processing lard). It can also be used as analytical reagent.
7. It can be used as condensing agent in organic synthesis.
In the following content analysis and quality indicators analysis, the sample should try to avoid exposure to air, and it is preferably carried out in nitrogen.
Content analysis and sodium carbonate, sodium hydroxide analysis.
Select two constant weight weighing bottle, whose diameter is about 30mm, height is about 80mm and which is almost full of sample. The bottle is carefully stamped and weighed. It should be 12~15g.
Determination of alkalinity of sodium methanolate(CH3ONa). Remove the capsule of a sample bottle and let the sample bottle along the border quickly slid into a 500ml Erlenmeyer flask, which contains 200ml ice water removal of the carbon dioxide. Splashing should be prevented. Immediately plug flask with a rubber stopper, and shake to dissolve the sample. The sample is washed by decarbonation water into a 250ml volumetric flask, and dilute to the mark with almost. When the solution is allowed to reach room temperature, add water to constant volume and mixed. Take 50.0ml of the solution and transfer to 500ml conical flask with glass stopper. Add 150ml decarbonation water and 5ml barium chloride test solution (TS-37). Keep for 5min after the flask is stoppered and the solution is mixed. Add 3 drop Phenolphthalein test solution (TS-167), and titrate with 1mol/L hydrochloric acid until the pink color disappears. Reserve the titrated solution for the determination of sodium carbonate. The percentage A of sodium methanolate alkalinity is calculated as follows:
A = (V1×c×5.403)/(W×0.2).
Where V1--volume of hydrochloric acid consumed, m1;
c--concentration of hydrochloric acid consumed, mol/L;
W--quality of sample, g
Determination of sodium carbonate. Add 2 drops methyl orange test solution (TS-148) into the above-mentioned titrated solution. And then continuously titrate with 1mol/L hydrochloric acid to persistent pink. The percentage of sodium carbonate (as Na2CO3) is calculated as follows:
The content of Na2CO3 (%) = (V2×cf×5.30)/(W×0.2)
Where V2--volume of hydrochloric acid consumed by the titration of the second time, ml;
c and W--same meaning with above-mentioned determination of alkalinity of sodium methanolate.
Determination of sodium hydroxide. It can be carried out with reference to the GT-32 Karl Fischer titration method, or the following method.
Solution A. Add 400ml colorless pyridine of which the water content does not exceed 0.05% into a 500ml flat-bottomed flask. Plug rubber stopper with double hole, and plug a 7mm glass tube inside a hole extending down near the bottom of the flask. Plug an exhaust pipe inside the other hole which is fitted with hose clamped with clips. Place the flask in a cooling tank filled with circulating water. Walter dry sulfur dioxide (80±0.5)g from an upstanding cylinder. Before the valve is closed, the exhaust pipe should be released. Transfer the solution into a dried flask with glass stopper. Add 400ml anhydrous methanol. After mixed, it can be stored in the dark.
Solution B is stored in a dried glass bottle with stopper containing 900ml anhydrous methanol. Add 75g iodine. Shake the bottle until that iodine dissolves, and then move into the automatic burette that it protected by drying tube.
The calibration of solution B. Measure 15ml solution A with a drying cylinder, and transfer that into a 125ml dry iodine bottle. Titrate it with solution B to brown. Immediately stopper iodine bottle to prevent moisture absorption and end disappearing. The amount of solution B added should not be counted. Add 50ml standard methanol/water solution that 1ml methanol contains 1.0mg water into the iodine bottle. Immediately titrate it with solution B to the same brown. Calculate equivalent factor F: the mass of water in 1ml solution B (mg). This calibration work should be required on a daily basis.
Select two 120ml jars with plastic screw cap. Firstly wash the two jars with hydrochloric acid, and then rinse them with water. Finally rinse them with isopropyl alcohol and dry them with airflow. Drill a hole in the spare plastic screw cap so that it can be accessed in an automatic burette tip. Add a magnetic stirring rod into each bottle, and flow dry nitrogen to remove carbon dioxide. Add 30ml solution A and 1.5ml anhydrous methanol into each bottle, and screw on the lid. Take the auxiliary lid to replace one of them, insert the tip of the burette, and start to stir. Titrate it with solution B to brown, and maintain that at least 5min. Change to the original lid. Titrate another solution in the same way. Remove the lids of the two bottles. Accurately weigh 2g sample from the prepared samples in one of the two bottles by reduction method and add the sample into another. Reconnect the lid on the two bottles. Titrate it with solution B (the first one bottle) to brown. And then titrate the blank (only the second bottle). Percent of water A in the sample is calculated as follows:
A(%) = (F×V×100)/(w×1000)
Where F--Equivalent factor of solution B, mg/ml;
y--the net volume of solution B that the sample consumes, ml;
w--Quality of sample, g.
Calculation. The percent content (A)of sodium hydroxide is calculated by the following formula:
A (%) = 2.222×[% H2O-(% NaCO3×0.170)]
Finally the percent content (B) of sodium methoxide is calculated by the following formula:
B (%) =% AO (% NaOH×1.350)
Arsenic. Take 1g sample. Dissolve the sample carefully in 10ml of water. Neutralize the solution with dilute sulfuric acid test solution (TS-241) to neutral using litmus paper. Then dilute it to 35ml with water as a sample solution. And then determine the sample solution by the GT-3 method.
Heavy metals. Take 800mg sample. Dissolve the sample carefully in 10ml of water. Add 10ml dilute hydrochloric acid test solution (TS-117). Heat the solution to boiling. Cool and dilute it with water to 25ml as a liquid sample solution. Determine the sample solution by the GT-16 method. The amount of lead ions (Pb) in control solution (solution A) is 20μg.
Lead. Take 1g sample. Dissolve the sample carefully in 10ml of water. Add 10ml dilute hydrochloric acid test solution (TS-117). Heat the solution to boiling. Cool and dilute it with water to 25ml as a liquid sample solution. Determine the sample solution by the GT-18 method. The amount of lead ions (Pb) in control solution (solution A) is 10μg.
Mercury. Take 2g sample. Place the sample in a small beaker and dissolve it carefully in 10ml of water. Add two drops phenolphthalein test solution (TS-167). Slowly neutralize the solution with 20% sulfuric acid solution under constant stirring. Add 1ml 1:5 dilute sulfuric acid solution and 1ml 1:25 potassium permanganate solution, and make the two mix. Use it as sample solution. And then determine the sample solution by the GT-22 method.