Trimethyl Phosphate CAS 512-56-1

1. Phosphorus oxychloride reacts with methanol in the presence of potassium carbonate to generate it. Simultaneously react to generate dimethyl phosphate potassium salt, then react with dimethyl sulfate to generate it. The crude product of it is washed with water, decolorized, dehydrated and distilled under reduced pressure to obtain the finished product. Raw material consumption quota: phosphorus oxychloride 1094kg/t, methanol 686kg/t.

2. Add methanol and potassium carbonate to the reaction pot, cool to 5°C, start adding phosphorus oxychloride dropwise, keep the temperature below 30°C, after 2h dropwise, stir for 0.5h, and control the pH value at 7-8; Then add dimethyl sulfate, recycle methanol for 3 hours, then cool the material in the pot to below 20°C, add carbon tetrachloride to filter, wash the filter cake with a small amount of carbon tetrachloride, combine the lotion and filtrate, and recover tetrachloride carbonized, and distilled under reduced pressure to obtain the crude product.

Add distilled water and activated carbon to the crude product, add anhydrous potassium carbonate for dehydration after filtration, and finally obtain the product by distillation under reduced pressure.

The production of it is mainly divided into two types: one is the reaction of trimethylfosfat obtained from formaldehyde through chloroform, and the other is the reaction of it obtained from chloral through chloroform, wherein formaldehyde the temperature of the reaction with chloral is required to be above 100 degrees Celsius, while the reaction containing Australian needs to be heated to 150 degrees Celsius.

In addition, since there is a decomposition reaction in the reaction, it is necessary to add a stabilizer to prevent the decomposition of the reactant.

At present, the research on the production process of it mainly focuses on the research on the reaction temperature and stable production. An improved process is to use low-temperature reaction to reduce the reaction temperature to 50-60 degrees Celsius, which can greatly reduce energy consumption and increase the yield of it.

Another improved process is to use photocatalyst, which can effectively inhibit the decomposition reaction in the reaction, thereby greatly increasing the yield of it. In addition, microwave technology or ionizing radiation technology can also be used to increase the reaction temperature, thereby effectively increasing the yield of it.

In a word, the production process of product has always been the focus of research. The corresponding improvement technology is also constantly developing. Combining traditional reaction technology with new technology can effectively improve the production efficiency of trimethylfosfat, thus ensuring the market demand.

In 1811, French chemist Thenard first reported the formation of esters through the reaction of phosphoric acid with ethanol, which is considered the beginning of organophosphate chemistry. In the following decades, scientists discovered various alkyl phosphate esters, but clear records of trimethylfosfat did not appear until the mid-19th century.

In 1847, German chemist August Wilhelm von Hofmann first isolated and described trimethylfosfat while studying the reaction between methanol and phosphorus pentoxide. In his paper published in the Journal of the German Chemical Society, Hofmann detailed the physical properties of this new compound, including its unique solubility and volatility.

In the second half of the 19th century, with the development of organic structure theory, many chemists devoted themselves to elucidating the structure of trimethylfosfat. In 1873, Russian chemist Alexander Mikhailovich Zaitsev confirmed through systematic chemical degradation experiments that the compound discovered by Hofmann was indeed a fully esterified product formed by three methyl groups and phosphoric acid. The synthesis methods during this period mainly relied on the direct reaction of methanol with phosphorus pentoxide or phosphoryl chloride, with low yields and many by-products.

At the beginning of the 20th century, with the advancement of physical and chemical analysis methods, the structural research of trimethylfosfat entered a new stage. In 1905, British chemist Thomas Martin Lowry first determined the molecular weight of trimethylfosfat using the freezing point method, and the results were highly consistent with theoretical values, providing key evidence for confirming its molecular formula. In the 1920s, the application of X-ray diffraction technology enabled scientists to study the molecular configuration of trimethylfosfatmore intuitively.

In 1935, American chemist Linus Pauling discovered in his research that the phosphorus oxygen bond in trimethylfosfat molecules had partial double bond properties, which was of great significance for understanding the electronic structure of phosphate compounds. Pauling's research shows that the phosphorus atom in trimethylfosfat adopts sp3 hybridization, forming sigma bonds with three methoxy groups and d π - p π bonds with oxygen atoms. This electronic structure explains the relative stability of trimethylfosfat.

During World War II, the military application of infrared spectroscopy and Raman spectroscopy technology promoted the study of vibrational spectra of trimethylfosfat. In 1943, American chemist Richard C. Lord first reported the complete infrared spectrum of trimethylfosfat, providing important reference for subsequent structural analysis. The emergence of nuclear magnetic resonance technology in the 1950s enabled scientists to study the molecular structure and conformational changes of trimethylfosfat more accurately.

The industrial production method of trimethylfosfat has undergone multiple technological innovations. Early industrial production (1920-1940) mainly used the reaction route of methanol and phosphorus oxychloride (POCl3), which was optimized by German chemist Gerhard Schrader in 1927. The reaction conditions were slow dropwise addition of methanol at low temperature (0-5 ℃), and the yield could reach 75%. However, this method generates a large amount of corrosive hydrogen chloride by-products and requires high equipment requirements.

In the 1950s, Monsanto, an American company, developed a direct esterification process between methanol and phosphorus pentoxide. The reaction was carried out under mild conditions (60-80 ℃), using inert solvents to reduce side reactions, and the yield increased to over 85%. The improved version of this process is still one of the main methods of industrial production today. In the 1960s, Japanese scientists developed a gas-phase catalytic esterification method, which reacted methanol with phosphoric acid in the gas phase in the presence of alumina catalyst, achieving continuous production.

In the 21st century, the concept of green chemistry has promoted the innovation of the synthesis method of trimethylfosfat. In 2008, the Chinese Academy of Sciences developed an ionic liquid catalytic system to make the reaction conditions more moderate (at room temperature), and the catalyst can be recycled. In 2015, BASF, a German company, reported a new synthesis process based on supercritical methanol, which significantly improved reaction efficiency while reducing energy consumption and waste generation.

Gas chromatography (GC) coupled with a flame ionization detector (FID) is the primary routine quantitative technique for trimethyl phosphate. A weakly polar capillary column can be adopted, and programmed temperature rise is utilised to separate sample components.

Quantification is carried out via external standard method or internal standard method. This approach is suitable for purity testing of industrial raw materials and screening of trace impurities.

For polar impurities such as trace phosphate ions and methanol, supplementary testing can be performed by combining ion chromatography (IC) with gas chromatography. High-performance liquid chromatography (HPLC) sees limited application here and is mostly used for analysing its hydrolysis products.

GC-MS is recommended for qualitative confirmation, where structural verification is achieved through matching characteristic fragment ions.Water content is determined in accordance with the volumetric Karl Fischer method.

Tests for heavy metals and ignition residues follow general physical and chemical testing specifications for chemical products. This compound exhibits relatively strong polarity; harsh hydrolytic conditions shall be avoided during sample pre-treatment to prevent decomposition of the target analyte, which would interfere with test results.