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Method for producing triethyl orthoformate and main use thereof

Nov. 07, 2019

Triethyl orthoformate, also known as triethoxymethane, has a pungent odor liquid, has a low melting point, is miscible with ethanol and diethyl ether, and is slightly soluble in water.

As an important chemical raw material, triethyl orthoformate has about four synthetic methods. (These four methods have all been tested by the Haihang industry. The quality of the products is slightly different.)

1. Sodium ethoxide method: using sodium ethoxide and chloroform as raw materials, reacting at 60-65 ° C to form crude triethyl orthoformate, and then fractionating and refining to obtain a finished product.

2. Ethanol method: ethanol and sodium hydroxide are used instead of sodium ethoxide, and the catalyst is PTC by solid-liquid phase transfer catalysis.

3. Benzoyl chloride method: using benzoyl chloride, formamide and absolute ethanol as raw materials, under the action of a catalyst, a mixture of triethyl orthoformate, benzoic acid and ammonium chloride is formed, and the finished orthoformic acid is obtained by separation. Ethyl ester and benzoic acid.

3. Place 3 liters of absolute ethanol and 490 grams (327 mL, 4.1 moles) of chloroform in a 5 liter round bottom flask equipped with an 80 cm long reflux condenser. The flask should be placed in an easily water-cooled position. 207 grams (9 grams of atom) of clean metallic sodium was cut into small tombs that could be adapted to fall from the condenser and then added to the solution in about two hours. In order to add sodium metal at this rate, the flask must be cooled while sodium is added. When the sodium metal has fully acted and the mixture has cooled to room temperature, the sodium chloride is filtered off by suction filtration using a drying apparatus, and the sodium oxide on the filter paper is washed with 200 ml of absolute ethanol to allow the washing liquid to flow into the filtrate obtained above. in.

The filtrate was placed in a 3 liter flask equipped with an 80 cm fractionation column, and excess chloroform and most of the ethanol were distilled off in a steam bath or water bath. The distillate was collected in a 2 liter suction filter bottle equipped with a dry mash to isolate moisture. The distillation takes 5 to 6 hours. The mixture of chloroform and ethanol recovered in the distilled towel weighs about 2000 grams and can be used in the next experiment. The remaining liquid in the flask was subjected to decantation to remove a small amount of sodium sulfide, poured into a Kelvin flask equipped with a 30 cm column of radium, and distilled under normal pressure. The fraction below 85 ° C is mainly ethanol and will be discarded altogether; the fraction at 85-140 ° C is about 100 grams, which contains about one quarter of the total production of the original formic acid vinegar. This fraction can be fractionated, but it is best to incorporate it into the product of the next experiment. The original enemy vinegar is distilled at 140-146 ° C and weighs 120-140 g (27-31%).

After the first experiment, 400 g of chloroform was added to the recovered chloroform-ethanol mixture in an amount of sufficient anhydrous sodium (800-1000 ml) to bring the total sum to 3 liters. Then add metal sodium to the previous rod. After the excess chloroform and ethanol have been distilled from the distillation column, the middle portion of the previous experiment is added and then fractionated. The yield of this experiment was about 45%.

The use of triethyl orthoformate is very extensive, and the following uses are based on the customer's introduction to the preparation of triethyl orthoformate produced by the Haihang industry.

1. Triethyl orthoformate is an alkylation reagent and a formylation reagent commonly used in chemical laboratories. They are easy to store but highly reactive. They can be used as alkylating agents to transfer alkyl groups to various alcoholic hydroxyl groups; when used as formylating agents, they can be used under acidic or basic conditions.

When an alkylation reaction with an alcohol is carried out as an alkylating agent, triethyl formate can be used to cause a corresponding alkylation reaction of various alcohols. The polyol can be alkylated to form the corresponding cyclic orthoformate.

The protected orthoformate of the aldehyde or ketone can be used to protect the aldehyde and ketone to form the formate and the corresponding acetal or ketal.

Formylation The orthoformate can be used as a formylating reagent under Lewis acid catalysis. Compared with other formylating reagents, it has the characteristics of simple operation and high yield. The orthoformate easily forms a dialkoxy-normal carbon ion in situ under acid catalysis and can be directly used for the formylation reaction. Such a formylation reaction can be carried out on the α-C ortho to the carbonyl group.

Reacting with an Enol (or Analog) The enolate of the enol's silyl ether or ketone can be reacted with a normal carbon ion formed in situ by the orthoformate to form a β-acetal ketone compound.

2. Used in organic synthesis and as a pharmaceutical intermediate and photosensitive material.

Triethyl orthoformate is an intermediate of the acaricide diammonium and the herbicide pyrazosulfuron, and can also be used for the manufacture of antimalarial drugs such as chloroquine and quinoline.

The raw material for medicine is a synthetic raw material for antimalarial drugs such as chloroquine and quinoline. Also used in the production of high polymers, photographic drugs, photosensitive materials, anti-halation dyes, cyanine dyes and synthetic pesticides.

The above is the introduction and preparation of the manufacturing method and main use of triethyl orthoformate in Haihang industry. If you are interested in other information on triethyl orthoformate, please contact us for more information.

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