Preparation method of higher sodium alkoxide

Abstract

The invention belongs to the technical field of chemical synthesis, and particularly relates to a preparation method of higher sodium alkoxide. The preparation method of the higher sodium alkoxide comprises the following steps: (1) filling a fixed bed reactor with a sodium hydroxide solid to form a 4-5cm stacked bed layer; (2) introducing higher alcohol and raising the temperature for reaction to obtain reaction liquid; and (3) raising the temperature of the reaction liquid to the boiling point of the used higher alcohol, and evaporating the higher alcohol to obtain the solid higher sodium alkoxide. The preparation method of higher sodium alkoxide provided by the invention has the advantages of mild reaction conditions, good green economy, good yield and high purity, and the reaction liquid can be recycled for continuous use.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a method for preparing a higher sodium alcoholate. Background Art

[0002] In the field of organic chemistry, higher sodium alcoholates RONa (R=C8~C12) are an important class of organic compounds. Due to their unique chemical properties and broad application prospects, they have long been closely watched by researchers and the industry. These compounds are mainly used in organic synthesis, especially in the fields of surfactants, lubricants, plastic additives and drug synthesis, showing great application potential. However, the efficient, economical and environmentally friendly preparation of higher sodium alcoholates remains a technical challenge.

[0003] There are many reports on the preparation methods of higher sodium alcoholates, but these methods all have certain limitations in practical applications. For example, a method for preparing sodium n-octanol is described in foreign patent DE519443, which is to react excessive n-octanol with sodium hydroxide and remove the generated water and excessive alcohol by azeotropic distillation. Although this method can achieve the preparation of sodium n-octanol to a certain extent, the economic benefit is low due to the high proportion of alcohol added, and in actual operation, it is necessary to introduce nitrogen or apply vacuum to assist distillation, which increases production cost and complexity.

[0004] Subsequently, in 1970, Lochmann et al. reported another method for preparing sodium n-dodecoxide in the journal Collection of Czechoslovak Chemical Communications. They added alcohol to a mixture containing metallic sodium (in the form of sodium wire with a diameter of 0.5 mm) and tetrahydrofuran, and kept the reaction under moderate boiling conditions for several hours. Although this method can prepare sodium n-dodecoxide, the reaction process is cumbersome and needs to be operated under argon overpressure. The subsequent filtration, concentration, crystallization and drying steps are relatively complicated, resulting in a low yield of the final product. In addition, the organic solvents such as tetrahydrofuran used in this method may also cause pollution to the environment, which is not in line with the development trend of green chemistry. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a method for preparing a higher sodium alcoholate, wherein the reaction conditions are mild, the reaction liquid can be recycled for further use, the method has good green economy, good yield and high purity.

[0006] The method for preparing the higher sodium alcoholate of the present invention comprises the following steps: (i) filling a fixed bed reactor with sodium hydroxide solid to form a packed bed; (ii) introducing a higher alcohol and raising the temperature to react to obtain a reaction solution; (iii) raising the temperature of the reaction solution to the boiling point of the higher alcohol used, distilling off the higher alcohol to obtain solid higher alcohol sodium.

[0007] In step (i), a 4 to 5 cm high accumulation bed is formed.

[0008] The higher alcohol is C8-C12 alcohol. The fixed bed reactor model of step (i) is H-Flow-S30 Oushisheng fixed bed reactor.

[0009] The reaction temperature in step (ii) is 110-140° C., and the reaction time is 3-6.5 h.

[0010] The temperature in step (iii) is raised to 200-270°C.

[0011] The molar ratio of the higher alcohol to sodium hydroxide is 0.5:1-4:1.

[0012] Specifically, the preparation method of the higher sodium alcoholate comprises the following steps: (i) Sodium hydroxide solid is loaded into a fixed bed reactor to form a 4-5 cm thick bed layer.

[0013] (ii) introducing a higher alcohol and raising the temperature to 110-140°C for a reaction time of 3-6.5 hours, and evaporating water to obtain a reaction solution. The molar ratio of the higher alcohol to sodium hydroxide is 0.5:1-4:1.

[0014] (iii) Drain the liquid and raise the temperature to the boiling point of the higher alcohol used, 200-270°C, to evaporate the alcohol. The evaporated higher alcohol can be recovered for further use, and the remaining solid is the desired higher alcohol sodium.

[0015] The reaction is as follows: .

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides an efficient and economical method for preparing higher sodium alcohols. By reacting solid sodium hydroxide with higher alcohols in a fixed bed reactor, mild reaction conditions are achieved, avoiding the need for high temperature, high pressure or complex operations in traditional methods, and significantly reducing production costs and safety risks.

[0017] (2) The method for preparing higher sodium alcohol of the present invention can recycle the reaction liquid for further use, thereby improving resource utilization and reducing waste discharge, which is in line with the concepts of green chemistry and sustainable development. This not only contributes to environmental protection, but also brings long-term economic benefits to the enterprise.

[0018] (3) The preparation method of the present invention achieves a high yield and high purity of higher sodium alcohol by optimizing the reaction conditions and raw material ratio, providing high-quality raw materials for the fields of surfactants, lubricants, plastic additives and drug synthesis. At the same time, the method is simple to operate and easy to realize industrial production, and has broad market application prospects. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with specific embodiments.

[0020] The raw materials and reagents used in the following examples and comparative examples are all commercially available products.

[0021] Example 1 The preparation method of sodium n-octanol comprises the following steps: (a) Sodium hydroxide solid was loaded into the H-Flow-S30 Oushisheng fixed bed reactor to form a 5 cm stacked bed.

[0022] (ii) introducing n-octanol and raising the temperature to 120° C. for a reaction time of 3 h, and evaporating water to obtain a reaction solution, wherein the molar ratio of n-octanol to sodium hydroxide is 0.5:1.

[0023] (iii) Drain the liquid and raise the temperature to the boiling point of the n-octanol used, 200°C, to evaporate the alcohol. The remaining solid is the desired sodium n-octanol. The yield of sodium n-octanol is 93%.

[0024] Example 2 The preparation method of sodium n-decyl alcohol comprises the following steps: (a) Sodium hydroxide solid was loaded into the H-Flow-S30 Oushisheng fixed bed reactor to form a 5 cm stacked bed.

[0025] (ii) introducing n-decanol and raising the temperature to 110° C. for a reaction time of 6 h, and evaporating water to obtain a reaction solution, wherein the molar ratio of n-decanol to sodium hydroxide is 0.5:1.

[0026] (iii) The liquid is discharged and the temperature is raised to the boiling point of the n-decanol used, 240°C, to evaporate the alcohol. The remaining solid is the desired sodium n-decanol. The yield of sodium n-decanol is 84%.

[0027] Example 3 The preparation method of sodium n-decyl alcohol comprises the following steps: (a) Sodium hydroxide solid was loaded into the H-Flow-S30 Oushisheng fixed bed reactor to form a 5 cm stacked bed.

[0028] (ii) introducing n-decanol and raising the temperature to 120° C. for a reaction time of 5 h, and evaporating water to obtain a reaction solution, wherein the molar ratio of n-decanol to sodium hydroxide is 0.9:1.

[0029] (iii) The liquid is discharged and the temperature is raised to the boiling point of the n-decanol used, 250°C, to evaporate the alcohol. The remaining solid is the desired sodium n-decanol. The yield of sodium n-decanol is 92%.

[0030] Example 4 The preparation method of sodium n-dodecoxide comprises the following steps: (a) Sodium hydroxide solid was loaded into the H-Flow-S30 Oushisheng fixed bed reactor to form a 5 cm stacked bed.

[0031] (ii) introducing n-dodecanol and raising the temperature to 135° C. for a reaction time of 6.5 h, and evaporating water to obtain a reaction solution. The molar ratio of n-dodecanol to sodium hydroxide is 1.4:1.

[0032] (iii) The liquid is discharged and the temperature is raised to the boiling point of the n-dodecanol used, 270°C, to evaporate the alcohol. The remaining solid is the desired sodium n-dodecanol. The yield of sodium n-dodecanol is 81%.

[0033] Example 5 The preparation method of sodium n-dodecoxide comprises the following steps: (a) Sodium hydroxide solid was loaded into the H-Flow-S30 Oushisheng fixed bed reactor to form a 4 cm stacked bed.

[0034] (ii) introducing n-dodecanol and raising the temperature to 140° C. for a reaction time of 5.5 h, and evaporating water to obtain a reaction solution. The molar ratio of n-dodecanol to sodium hydroxide is 3:1.

[0035] (iii) The liquid is discharged and the temperature is raised to the boiling point of the n-dodecanol used, 260°C, to evaporate the alcohol. The remaining solid is the desired sodium n-dodecanol. The yield of sodium n-dodecanol is 92%.

[0036] Comparative Example 1 The preparation method of sodium n-octanol comprises the following steps: (a) Sodium hydroxide solid was loaded into the H-Flow-S30 Oushisheng fixed bed reactor to form a 5 cm stacked bed.

[0037] (ii) introducing n-octanol and raising the temperature to 160° C. for a reaction time of 3 h, and evaporating water to obtain a reaction solution, wherein the molar ratio of n-octanol to sodium hydroxide is 0.5:1.

[0038] (iii) The liquid is discharged and the temperature is raised to the boiling point of the n-octanol used, to 200°C, to evaporate the alcohol. The remaining solid is the desired sodium n-octanol. The yield of sodium n-octanol is 56%.

[0039] Comparative Example 2 The preparation method of sodium n-decyl alcohol comprises the following steps: (a) Sodium hydroxide solid was loaded into the H-Flow-S30 Oushisheng fixed bed reactor to form a 5 cm stacked bed.

[0040] (ii) introducing n-decanol and raising the temperature to 110° C. for a reaction time of 6 h, and evaporating water to obtain a reaction solution, wherein the molar ratio of the higher alcohol to sodium hydroxide is 0.2:1.

[0041] (iii) The liquid is discharged and the temperature is raised to the boiling point of the n-decanol used, 240°C, to evaporate the alcohol. The remaining solid is the desired sodium n-decanol. The yield of sodium n-decanol is 34%.

[0042] Comparative Example 3 The preparation method of sodium n-decyl alcohol comprises the following steps: (a) Sodium hydroxide solid was loaded into the H-Flow-S30 Oushisheng fixed bed reactor to form a 5 cm stacked bed.

[0043] (ii) introducing n-decanol and raising the temperature to 120° C. for a reaction time of 5 h, and evaporating water to obtain a reaction solution, wherein the molar ratio of n-decanol to sodium hydroxide is 5.5:1.

[0044] (iii) Drain the liquid and raise the temperature to the boiling point of the n-decanol used, 250°C, to evaporate the alcohol. The remaining solid is the desired sodium n-decanol. The yield of sodium n-decanol is 12%.

[0045] Comparative Example 4 The preparation method of sodium n-dodecoxide comprises the following steps: (a) Sodium hydroxide solid was loaded into the H-Flow-S30 Oushisheng fixed bed reactor to form a 2 cm packed bed.

[0046] (ii) introducing n-dodecanol and raising the temperature to 135° C. for a reaction time of 6.5 h, and evaporating water to obtain a reaction solution. The molar ratio of n-dodecanol to sodium hydroxide is 1.4:1.

[0047] (iii) Drain the liquid and raise the temperature to the boiling point of n-dodecanol used, 270°C, to evaporate the alcohol. The remaining solid is the desired sodium n-dodecanol. The yield of sodium n-dodecanol is 35%.

[0048] Comparative Example 5 The preparation method of sodium n-dodecoxide comprises the following steps: (a) Sodium hydroxide solid was loaded into the H-Flow-S30 Oushisheng fixed bed reactor to form an 8 cm stacked bed.

[0049] (ii) introducing n-dodecanol and raising the temperature to 140° C. for a reaction time of 5.5 h, and evaporating water to obtain a reaction solution. The molar ratio of n-dodecanol to sodium hydroxide is 3:1.

[0050] (iii) The liquid is discharged and the temperature is raised to the boiling point of the n-dodecanol used, 260°C, to evaporate the alcohol. The remaining solid is the desired sodium n-dodecanol. The yield of sodium n-dodecanol is 11%.

Claims

1. A method for preparing a higher sodium alcoholate, characterized in that: The following steps are involved: (i) filling a fixed bed reactor with sodium hydroxide solid to form a packed bed; (ii) introducing a higher alcohol and raising the temperature to react to obtain a reaction solution; (iii) raising the temperature of the reaction solution to the boiling point of the higher alcohol used, distilling off the higher alcohol to obtain solid higher alcohol sodium.

2. The method for preparing a higher sodium alcoholate according to claim 1, wherein: In step (i), a 4 to 5 cm high accumulation bed is formed.

3. The method for preparing a higher sodium alcoholate according to claim 1, wherein: The higher alcohols are C8~C12 alcohols.

4. The method for preparing a higher sodium alcoholate according to claim 1, wherein: The reaction temperature in step (ii) is 110-140° C., and the reaction time is 3-6.5 h.

5. The method for preparing a higher sodium alcoholate according to claim 1, wherein: The temperature in step (iii) is raised to 200-270°C.

6. The method for preparing a higher sodium alcoholate according to claim 1, wherein: The molar ratio of the higher alcohol to sodium hydroxide is 0.5:1-4:1.