JPS5939705A - Manufacture of fluorinated phosgene - Google Patents

Abstract

PURPOSE:To manufacture very easily high purity fluorinated phosgene in a high yield by reacting trichloromethyl chloroformate with an alkali metallic fluoride in acetonitrile. CONSTITUTION:Trichloromethyl chloroformate is added to a mixture of acetonitrile with an alkali metallic fluoride such as KF, and by reacting them under heating, high purity fluorinated phosgene is obtd. as gas without requiring a purifying stage. The fluorinated phosgene is immediately used in the following stage as it is. It may be filled into a cylinder and used as required.

Description

[Detailed description of the invention] The present invention relates to a new method for producing fluorinated phosgene.

More specifically, trichloromethyl chloroformate (
The present invention relates to a method for producing fluorinated phosgene by fluorinating TCP (hereinafter abbreviated as TCP) with an alkali metal fluoride.

Fluorinated phosgene is an indispensable and useful compound as a raw material for the synthesis of pharmaceutical intermediates, such as dyes and agricultural chemicals.

Conventionally, a method for producing phosgene fluoride is a method in which phosgene and hydrofluoric acid are reacted in an iron autoclave at 140 to 150°C in the presence of activated carbon.
lns El 5 p-22, and West German Patent No. 15
9.956 publication specifies that 80F and phosgene are 4
A method is disclosed in which the reaction is carried out at 400° C. in the presence of an anhydrous ferric chloride catalyst using an iron tube reactor at a ratio of 1:1. All of these methods are '111i temperature reactions, require separation and purification of unreacted phosgene and fluorinated phosgene, and are difficult to obtain highly pure fluorinated phosgene. Furthermore, when using hydrofluoric acid, it is difficult to select the material for the equipment, and this is not a method that can be industrialized at all.

In addition, Japanese Patent Publication No. 1983-1999. In the specification of 158396 publication,
A method is described in which phosgene is introduced into a mixture of hydrofluoric acid and triethylamine in acetonitrile. This method solves the problem of corrosion of the equipment material because it reacts at low temperatures, but because it uses a large amount of triethylamine, it is difficult to recover triethylamine industrially.
This cannot be said to be an industrially advantageous method, as reuse must be considered.

As a result of intensive studies to overcome these problems, the present inventors have discovered that highly pure fluorinated phosgene can be easily obtained from TCP and alkali metal fluoride without the need for a purification process. Heading This invention has been established.

That is, the present invention is a method for producing phosgene fluoride, which is characterized by reacting TCP and an alkali metal fluoride in acetonitrile.

In the method of the present invention, when KTCF, a mixed system of acetonitrile and an alkali metal fluoride, is added and reacted under heating, the generated phosgene fluoride is obtained as a gas from within the reaction system. This fluorinated phosgene can be used as it is for the next reaction immediately, or it can be filled into a cylinder and used when necessary.

In the present invention, acetonitrile is preferred as the reaction solvent.

Other methods, such as dimethylsulfamide, produce phosgene by decomposition of TCP, and fluorinated phosgene cannot be obtained. The amount used is not particularly limited, but it may be used in an amount necessary to ensure good stirring when the alkali metal fluoride is added. TCP, which is usually an alkali metal fluoride as a starting material for the present invention, is industrially produced by phosgenation of methanol, methyl chloroformate, and further chlorination, and is easily available.

Alkali metal fluorides used as fluorinating agents include sodium fluoride, potassium fluoride, lithium fluoride, etc., but in order to obtain fluorinated phosgene with high purity and high yield, K is used as a spray-dried fluoride. Preferably, potassium oxide is used.

The amount of alkali metal fluoride used is 4.0 compared to TCFK.
The molar ratio is 12.0 times to 12.0 times, preferably 4.2 to 6.0 times.

The reaction temperature is below the boiling point of acetonitrile,
Preferably it is 50 to 80°C.

Generally, TCP is added in its entirety at 50° C. or lower, and then the temperature is raised and the reaction is carried out under reflux, but it is also possible to maintain the reaction system at 50 to 80° C. and add TCP to carry out the reaction.

As described above, according to the method of the present invention, fluorinated phosgene can be produced extremely easily and with high purity and high yield.

Hereinafter, the present invention will be explained in detail by giving examples.

Example 1 120 parts of acetonitrile and 35 parts of spray) dried potassium fluoride (manufactured by Morita Chemical) were mixed at room temperature,
Add 20 parts of TCP to this while stirring and keeping the temperature below 50℃.
was added dropwise over a period of 1 hour. The temperature was further increased to 50°C in about 1 hour, and the reaction was continued at 50 to 80°C for 5 hours. IR analysis of the gas generated during the reaction confirmed that it was pure fluorinated phosgene. The total amount of gas generated is aaso=e<
2s°C).

Example 2 The reaction was carried out in the same manner as in Example 1, except that sodium fluoride pulverized into about 100 meshes was used in place of the spray-dried potassium fluoride. As a result of the IR analysis of the generated gas, pure fluorinated phosgene was obtained. The total amount of gas generated was 6460-.

Hodogaya Chemical Industry Co., Ltd. Procedural Amendment (Voluntary) July 1981 4IJ Director General of the Patent Office 1, Indication of the Case 1988 Special Patent No. 8' [Akenbe 150051 No. 2, Title of Invention: Manufacture of phosgene fluoride Law 3, Relationship with the case of the person making the amendment Patent applicant Postal code: 105 Address: 4-2 Toramon-chome, Minato-ku, Tokyo
Name (531) Hodogaya Chemical] Nigyo Co., Ltd. Representative Director and President Ren Fujioka - Story
504-8723 5, l1tiCorrect content (1) "Dimedyl sulfoamide 11" on page 3, line 15
is corrected to "dimethyl sulfoxy 1".

Hodogaya Chemical Industry Co., Ltd.

Claims (1)

[Claims] A method for producing phosgene fluoride, which comprises reacting tricumylomethyl chloroformate and an alkali metal fluoride in acetonitrile.