Preparation method of carbonyl halide

Abstract

The purpose of the present invention is to provide a safe and efficient method for producing carbonyl halide. The method for producing a carbonyl halide according to the present invention is characterized by comprising a step for irradiating a halomethane having one or more halogen groups selected from the group consisting of chlorine, bromine and iodine with light in the presence of oxygen and ozone.

Description

Technical Field

[0001] The present invention relates to a method for safely and efficiently preparing carbonyl halides. Background Art

[0002] Carbonyl halides such as phosgene are very important as synthetic intermediates for various compounds and raw materials for raw materials. For example, carbonate compounds are usually prepared from phosgene and alcohol compounds.

[0003] However, phosgene easily reacts with water to form hydrogen chloride and has a history of being used as a poisonous gas, so it is very toxic. Phosgene is mainly prepared by a highly exothermic gas-phase reaction of anhydrous chlorine gas and high-purity carbon monoxide in the presence of an activated carbon catalyst. The carbon monoxide used here is also toxic. The basic production process of phosgene has not changed significantly since 1920. Preparing phosgene by this process requires expensive and large equipment. However, due to the high toxicity of phosgene, ensuring extensive safety is essential for equipment design, which leads to an increase in production costs.

[0004] Therefore, the research group of the inventors of the present invention developed a technique for generating halogens and / or carbonyl halides by irradiating halogenated hydrocarbons such as chloroform with light in the presence of oxygen (Patent Document 1). In addition, it was also found that carbonyl halides can be efficiently prepared by irradiating a mixed gas containing C 2-4 halogenated hydrocarbon and oxygen with high-energy light in the gas phase (Patent Document 2). Furthermore, it was also found that carbonyl halides can be efficiently prepared by irradiating a composition containing C 1-4 halogenated hydrocarbon with light in the presence of a substance such as chlorine that can generate free radicals under visible light and oxygen (Patent Document 3).

[0005] Non-Patent Document 1 describes that the oxidation reaction of tetrachloroethylene (Cl2C=CCl2) is initiated by chlorine atoms to generate phosgene and the like. In Non-Patent Document 1, the use of ozone is also described.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2013-181028

[0009] Patent Document 2: Pamphlet of International Publication No. 2022 / 172745

[0010] Patent Document 3: Pamphlet of International Publication No. 2021 / 045105

[0011] Non-Patent Documents

[0012] Non-Patent Document 1: ECKART MATHIAS et al., Can. J. Chem., VOL. 52, 1974, 3852-3862 SUMMARY OF THE INVENTION

[0013] Problems to be Solved by the Invention

[0014] As described above, it is known that the oxidative photodecomposition of carbonyl halides is promoted by chlorine.

[0015] However, chlorine has high corrosiveness and toxicity, and its handling requires the introduction of special corrosion-resistant equipment or safety equipment, etc., which increases the production cost. For these reasons, there is a need to develop an additive that is safer, less toxic and corrosive than chlorine and can be introduced at low cost.

[0016] Therefore, an object of the present invention is to provide a method for safely and effectively preparing carbonyl halides.

[0017] Means for Solving the Problems

[0018] The inventors of the present invention repeatedly conducted in-depth research to solve the above problems. As a result, although Non-Patent Document 1 concluded that ozone hinders the oxidation reaction of tetrachloroethylene initiated by chlorine atoms, the inventors of the present invention found that if ozone and oxygen are used in combination for the oxidative photodecomposition of halomethanes, carbonyl halides can be safely and effectively prepared even without using halogens such as chlorine, thus completing the present invention.

[0019] Hereinafter, the present invention will be described.

[0020] [1] A method for preparing carbonyl halides, characterized in that the method comprises: a step of irradiating light on a halomethane having one or more halogen substituents selected from chlorine, bromine and iodine in the presence of oxygen and ozone.

[0021] [2] The method according to [1] above, wherein light is irradiated on a mixed gas containing the halomethane, the oxygen and the ozone.

[0022] [3] The method according to [1] or [2] above, wherein the proportion of the ozone relative to the total of the oxygen and the ozone is 1 vol% or more and 20 vol% or less.

[0023] [4] The method according to [2] above, wherein the volume ratio of the halomethane to the ozone is 0.1 times or more and 50 times or less.

[0024] [5] The method according to [2] or [4] above, wherein the mixed gas does not contain chlorine.

[0025] [6]According to the method described in any one of [1]-[5] above, wherein the time for irradiating the halogenated methane with the light is 60 seconds or more and 5000 seconds or less.

[0026] [7]According to the method described in any one of [1]-[6] above, wherein the temperature when irradiating the halogenated methane with the light is 50 °C or more and 200 °C or less.

[0027] [8]A method for preparing a carbonate compound, characterized in that the method comprises:

[0028] a step of preparing a carbonyl halide by the method described in any one of [1]-[7] above; and

[0029] a step of reacting an alcohol compound with the carbonyl halide.

[0030] [9]A method for preparing a haloformate compound, characterized in that the method comprises:

[0031] a step of preparing a carbonyl halide by the method described in any one of [1]-[7] above; and

[0032] a step of reacting an alcohol compound with the carbonyl halide.

[0033]

[10] A method for preparing an isocyanate compound, characterized in that the method comprises:

[0034] a step of preparing a carbonyl halide by the method described in any one of [1]-[7] above; and

[0035] a step of reacting a primary amine compound with the carbonyl halide.

[0036]

[11] A method for preparing a carbamoyl halide compound, characterized in that the method comprises:

[0037] a step of preparing a carbonyl halide by the method described in any one of [1]-[7] above; and

[0038] a step of reacting a secondary amine compound with the carbonyl halide.

[0039]

[12] A method for preparing an amino acid-N-carboxylic acid anhydride, characterized in that the amino acid-N-carboxylic acid anhydride is a substance represented by the following formula (VIII), and the method comprises:

[0040] a step of preparing a carbonyl halide by the method described in any one of [1]-[7] above; and

[0041] a step of reacting an amino acid compound represented by the following formula (VII) with the carbonyl halide,

[0042] [Chemical Formula 1]

[0043]

[0044] In the formula,

[0045] R 4 represents an amino acid side chain group in which the reactive group is protected,

[0046] R 5 represents H or P 1 -[[-NH-CHR 6 -C(=O)-]] l -, in the formula, R 6 represents an amino acid side chain in which the reactive group is protected, P 1 represents a protecting group for the amino group, l represents an integer of 1 or more, and when l is an integer of 2 or more, multiple Rs 6 may be the same as or different from each other.

[0047]

[13] A method for preparing a Vilsmeier reagent, characterized in that the Vilsmeier reagent is a salt represented by the following formula (X), and the method includes:

[0048] A step of preparing a carbonyl halide by the method described in any one of the above [1]-[7]; and

[0049] A step of reacting the carbonyl halide with an amide compound represented by the following formula (IX),

[0050] [Chemical Formula 2]

[0051]

[0052] In the formula,

[0053] R 7 represents a hydrogen atom, C 1-6 alkyl or C 6-12 aromatic hydrocarbon group which may have a substituent,

[0054] R 8 and R 9 independently represent C 1-6 alkyl or C 6-12 aromatic hydrocarbon group which may have a substituent, and further, R 8 and R 9 may together form a ring structure having 4 or more and 7 or less members,

[0055] X represents a halogenated group selected from chlorine, bromine, and iodine,

[0056] Y - represents a counter anion,

[0057] [Chemical Formula 3]

[0058]

[0059] In the formula, R 7 -R 9 represents the same meaning as described above.

[0060] Effects of the present invention

[0061] According to the method of the present invention, using a halogenated methane with a high environmental load and restricted use and treatment as a raw material, useful carbonyl halides can be safely and effectively prepared. In addition, among halogenated methane products, there are products containing stabilizers, which hinder the oxidative photodegradation reaction of halogenated methane. However, the ozone used in the method of the present invention can decompose the stabilizer and promote the oxidative photodegradation reaction of halogenated methane. Further, in the method of the present invention, it is not necessary to use halogen gases such as highly corrosive or toxic chlorine gas. Therefore, the present invention is industrially useful as a technology capable of effectively utilizing halogenated methane and effectively preparing carbonyl halides such as carbonyl chloride. Description of the drawings

[0062] Figure 1 is a schematic diagram showing an example of the configuration of the reaction system used in the present invention.

[0063] Figure 2 is a schematic diagram showing an example of the configuration of the reaction system used in the present invention.

[0064] Figure 3 is a schematic diagram showing an example of the configuration of the reaction system used in the present invention.

[0065] Figure 4 is a schematic diagram showing an example of the configuration of the reaction system used in the present invention. Detailed embodiments

[0066] Hereinafter, each step of the method of the present invention will be described, but the present invention is not limited to the following specific examples.

[0067] 1. Oxidative photodegradation step

[0068] In this step, in the presence of oxygen and ozone, light is irradiated onto a halogenated methane having one or more halogen groups selected from chlorine, bromine, and iodine, thereby oxidatively photodegrading the halogenated methane to obtain a carbonyl halide.

[0069] The halogenated methane used in the present invention is methane having one or more halogen groups selected from chlorine, bromine, and iodine. Such a halogenated methane can be decomposed by oxygen, ozone, and light energy and converted into a carbonyl halide.

[0070] As described above, in the present invention, it is considered that halogenated methane is oxidized and photodecomposed, playing the same role as carbonyl halide. As the halogenated methane, polyhalogenated methane having two or more halogen groups is preferred, and perhalogenated methane in which all hydrogen atoms are substituted by halogen groups is also preferred.

[0071] As specific halogenated methane, for example, chloromethanes such as dichloromethane, chloroform, and carbon tetrachloride; bromomethanes such as dibromomethane and bromoform; iodomethanes such as iodomethane and diiodomethane; halogenated methane having two or more halogen groups such as bromochloromethane, chloroiodomethane, bromoiodomethane, and bromochloroiodomethane can be cited.

[0072] The halogenated methane can be appropriately selected according to the target chemical reaction or the desired product. In addition, one kind can be used alone, or two or more kinds can be used in combination. In addition, it is preferable to use only one kind of halogenated methane according to the purpose of preparing the target compound. Among the halogenated methane, from the viewpoints of gasification and cost, halogenated methane having chlorine is preferred, and chloroform is more preferred.

[0073] In general halogenated methane products, stabilizers that hinder the decomposition of halogenated methane, such as pentene or ethanol, are contained. In the present invention, in order to oxidize and photodecompose halogenated methane, halogenated methane from which the stabilizer has been removed can also be used. By using halogenated methane from which the stabilizer has been removed, visible light with relatively low energy can be used, or the light irradiation time can be reduced, etc., and halogenated methane can be decomposed more effectively. The method for removing the stabilizer from halogenated methane is not particularly limited. For example, after washing the halogenated methane with water to remove the water-soluble stabilizer, it can be dried. However, in the method of the present invention, since ozone is used, the stabilizer can be decomposed by ozone, and therefore, halogenated methane containing the stabilizer can be directly used.

[0074] As the halogenated methane used in the method of the present invention, in particular, inexpensive chloroform used as a general solvent can be used. In addition, for example, the halogenated methane used as a solvent can be recovered and reused. At this time, if a large amount of impurities or water is contained, the reaction may be hindered, so some degree of purification is preferred. For example, it is preferable to remove water or water-soluble impurities by washing with water and then dehydrate with anhydrous sodium sulfate or anhydrous magnesium sulfate, etc. However, even if about 1% by mass of water is contained, the reaction is considered to proceed, so excessive purification that reduces the productivity is not required. As the water content, it is more preferably 0.5% by mass or less, further preferably 0.2% by mass or less, and still further preferably 0.1% by mass or less. As the water content, it is preferably below the detection limit or 0% by mass. In addition, the recycled halogenated methane may also contain decomposition products of halogenated methane, etc.

[0075] Particularly, in cases where the halogenated methane is not a liquid under normal temperature and pressure or is difficult to vaporize, etc., a solvent can be used in combination with the halogenated methane. Additionally, the solvent may also promote the decomposition of the halogenated methane. Moreover, the solvent may inhibit the decomposition of the carbonyl halide caused by the oxidative photodegradation of the halogenated methane. As the solvent, a solvent that can moderately dissolve the halogenated methane is preferred. Examples of such solvents include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aliphatic hydrocarbon solvents such as n-hexane; aromatic hydrocarbon solvents such as benzene, toluene, xylene, and benzonitrile; ether solvents such as diethyl ether, tetrahydrofuran, and dioxane; and nitrile solvents such as acetonitrile.

[0076] The supply amount of oxygen can be appropriately adjusted within the range that can effectively oxidatively photodecompose the halogenated methane. For example, in the case of blowing oxygen into the liquid halogenated methane, 10 mL / min or more and 500 mL / min or less, 0.1 mmol / min or more and 50 mmol / min or less of oxygen can be supplied per 100 mL of the halogenated methane. As the above ratio, it is preferably 20 mL / min or more, more preferably 50 mL / min or more. Additionally, it is preferably 300 mL / min or less or 200 mL / min or less, more preferably 100 mL / min or less, preferably 0.5 mmol / min or more, more preferably 1 mmol / min or more, preferably 30 mmol / min or less or 20 mmol / min or less, more preferably 10 mmol / min or less or 5 mmol / min or less.

[0077] In the case of mixing gaseous halogenated methane and oxygen, for example, the volume ratio of oxygen to the halogenated methane can be 0.1 or more and 5 or less, and the molar ratio of oxygen to the halogenated methane can also be 0.1 or more and 5 or less. As the said volume ratio and molar ratio, it is preferably 0.2 or more, more preferably 0.5 or more. Additionally, it is preferably 3 or less or 2 or less, more preferably 1.5 or less.

[0078] In the method of the present invention, ozone is not a free radical substance, so its mechanism of action is unclear. However, it can promote the oxidative photodegradation of halomethane to obtain carbonyl halide, and it is possible to obtain higher molecular weight polymers using the generated carbonyl halide compared to the case of using only oxygen. In addition, it may be possible to decompose stabilizers of halomethane such as pentene by ozone. Furthermore, by decomposing or suppressing the generation of coloring components by ozone, coloring of the reaction solution or the target compound can be suppressed. The supply amount of ozone, for example, when blowing oxygen into liquid halomethane, 0.5 mL / min or more and 50 mL / min or less, 0.005 mmol / min or more and 5 mmol / min or less of ozone can be supplied per 100 mL of halomethane. The higher the ratio of ozone to halomethane, the better the oxidative photodegradation reaction of halomethane can proceed. On the other hand, the lower the ratio of ozone to halomethane, the more reliably the further photodegradation of the generated carbonyl halide can be suppressed. As the above ratio, it is preferably 1 mL / min or more, more preferably 2 mL / min or more. In addition, it is preferably 30 mL / min or less or 20 mL / min or less, more preferably 10 mL / min or less, preferably 0.01 mmol / min or more, more preferably 0.05 mmol / min or more, preferably 3 mmol / min or less or 2 mmol / min or less, more preferably 1 mmol / min or less or 0.5 mmol / min or less.

[0079] When mixing gaseous halomethane and ozone, for example, the volume ratio of ozone to halomethane can be 0.005 or more and 0.5 or less, and the molar ratio of ozone to halomethane can be 0.005 or more and 0.5 or less. As the above volume ratio and molar ratio, it is preferably 0.01 or more, more preferably 0.05 or more. In addition, it is preferably 0.3 or less or 0.2 or less, more preferably 0.15 or less.

[0080] When mixing gaseous halomethane and ozone, as the volume ratio of halomethane to ozone, for example, it can be 0.01 times or more and 100 times or less. As this ratio, it is preferably 0.05 or more, more preferably 0.1 or more or 1 or more. In addition, it is preferably 50 times or less or 20 times or less.

[0081] The ratio of oxygen and ozone can also be adjusted appropriately. For example, the ratio of ozone to the total of oxygen and ozone can be 1 vol% or more and 50 vol% or less. As this ratio, it is preferably 30 vol% or less, more preferably 20 vol% or less.

[0082] In addition to oxygen and ozone, inert gases such as nitrogen or argon can also be mixed. Additionally, air can also be used as the oxygen source. Air is advantageous from the perspective of cost. However, in the present invention, chlorine is preferably not used. Chlorine can promote the oxidative photodegradation of halomethanes, but chlorine has strong corrosiveness and toxicity, and special preparation equipment is required. In the present invention, in order to promote the oxidative photodegradation reaction of halomethanes, ozone, which is safer than chlorine, is used.

[0083] In this step, light is irradiated on halomethanes in the presence of oxygen and ozone. "In the presence of oxygen and ozone" can be a state where oxygen and ozone are dissolved in liquid halomethanes, or a state where gaseous halomethanes are mixed and contacted with oxygen and ozone. For example, as Figure 4 schematically shown, a mixed gas containing oxygen and ozone can be supplied to a composition containing halomethanes by bubbling. The composition containing halomethanes can be only halomethanes.

[0084] Alternatively, a mixed gas containing gaseous halomethanes, oxygen, and ozone can also be prepared, and the mixed gas can be irradiated with light. By irradiating the mixed gas with light, the oxidative photodegradation of halomethanes can be carried out more effectively. The preparation conditions of the mixed gas are not particularly limited. For example, as Figures 1-3 shown, after mixing halomethanes with oxygen and ozone, it can be transported to a heater, heated to above the boiling point of halomethanes to vaporize it, and then transported to a reactor. The upper limit of the heating temperature of halomethanes is not particularly limited as long as halomethanes are effectively vaporized. For example, it can be the boiling point + 50 °C.

[0085] Additionally, the oxidative photodegradation of halomethanes can also be carried out in a two-phase system of liquid phase and gas phase. For example, in the Figure 4 shown reaction system, while heating liquid halomethanes to above (boiling point - 10 °C) and below the boiling point using a heater, light is irradiated on both the liquid phase and the gas phase. At this time, by bubbling a mixed gas containing oxygen and ozone into the composition containing halomethanes, the vaporization of halomethanes is promoted. In order to further promote the vaporization of halomethanes, the mixture containing halomethanes can be stirred.

[0086] As the light for irradiating the halogenated methane, light containing high-energy light with short-wavelength light can be used. For example, light containing ultraviolet light can be used. By the high-energy light containing short-wavelength light, the halogenated methane can be effectively oxidized and photodecomposed. Specifically, light having a wavelength of 180 nm or more and 500 nm or less, and light having a peak wavelength included in the range of 180 nm or more and 500 nm or less can be used. In addition, the wavelength of the irradiated light can be appropriately determined. Light having a wavelength of 400 nm or less can be used, light having a wavelength of 300 nm or less can be used, and light having a peak wavelength included in these ranges can also be used. For example, light containing UV-B having a wavelength of 280 nm or more and 315 nm or less and / or UV-C having a wavelength of 180 nm or more and 280 nm or less can be used, light containing UV-C having a wavelength of 180 nm or more and 280 nm or less can be used, and light having a peak wavelength included in these ranges can also be used.

[0087] In the present invention, since the halogenated methane is oxidized and photodecomposed in the presence of ozone, even low-energy light can oxidize and photodecompose the halogenated methane. As the irradiated light with lower energy, light having a peak wavelength included in the visible light wavelength region can be cited. As the wavelength range of the lower-energy light, 250 nm or more and 830 nm or less can be cited, preferably 280 nm or more, more preferably 300 nm or more. In addition, preferably 800 nm or less or 700 nm or less, more preferably 600 nm or less or 500 nm or less, further preferably 400 nm or less, and also preferably light having a peak wavelength included in these ranges.

[0088] The light irradiation unit only needs to be able to irradiate the light of the above wavelength, and there is no particular limitation. As the light source for the light having such a wavelength range in the wavelength region, for example, sunlight, low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp, chemical lamp, black light lamp, metal halide lamp, LED lamp, etc. can be cited. From the viewpoints of reaction efficiency and cost, a low-pressure mercury lamp and an LED lamp are preferred, and an LED lamp is more preferred.

[0089] The conditions such as the intensity of the irradiated light can be appropriately set according to the halogenated methane, etc. For example, as the intensity of the desired light at the shortest distance position from the light source to the liquid or gaseous halogenated methane, although it also depends on the implementation scale, the wavelength of the irradiated light, etc., it is preferably 1 mW / cm 2 or more and 500 mW / cm 2 or less. For example, when the wavelength of the irradiated light is relatively short, as the light intensity, it is more preferably 100 mW / cm 2 or less or 50 mW / cm 2 or less, and further preferably 20 mW / cm 2 or less or 10 mW / cm 2Hereinafter, when the wavelength of the irradiated light is relatively long, as the light intensity, it is more preferably 10 mW / cm 2 or more or 20 mW / cm 2 or more, and can be 50 mW / cm 2 or more or 100 mW / cm 2 or more. Additionally, it is more preferably 400 mW / cm 2 or less or 300 mW / cm 2 or less, and further preferably 200 mW / cm 2 or less. Moreover, as the shortest distance between the light source and the halogenated methane, it is preferably 1 m or less, more preferably 50 cm or less, and further preferably 10 cm or less or 5 cm or less. There is no particular limitation on the lower limit of this shortest distance, and it can be 0 cm, that is, the light source can be present in the liquid or gaseous halogenated methane.

[0090] There is no particular limitation on the method of irradiating the halogenated methane with light. For example, as shown in Figure 1 and Figure 4 , it is sufficient to dispose the light source in a reactor containing liquid or gaseous halogenated methane. Additionally, as shown in Figure 2 and Figure 3 , one or more light sources can be disposed around a transparent reactor containing liquid or gaseous halogenated methane.

[0091] It is considered that the halogenated methane is photooxidatively decomposed into carbonyl halide by oxygen, ozone, and irradiated light. However, it is also known that carbonyl halide is particularly decomposed by high-energy photolysis. Therefore, it is important to adjust the light irradiation conditions to prevent excessive decomposition of the generated carbonyl halide.

[0092] For example, as the time for irradiating the halogenated methane with light, although it also depends on the wavelength of the irradiated light and the reaction temperature, it is preferably 1 second or more and 5000 seconds or less. The time for irradiating the flowing mixed gas containing halogenated methane, oxygen, and ozone with light can also be referred to as the residence time of the flowing mixed gas in the photoreaction vessel for continuously irradiating the mixed gas with light. If this time is 1 second or more, the halogenated methane can be more reliably photooxidatively decomposed, and if it is 5000 seconds or less, the excessive decomposition of the generated carbonyl halide can be more reliably suppressed. As this time, it is preferably 5 seconds or more or 10 seconds or more, more preferably 30 seconds or more or 60 seconds or more, further preferably 120 seconds or more or 600 seconds or more. Additionally, it is preferably 3000 seconds or less, more preferably 2000 seconds or less, and further preferably 1000 seconds or less. Furthermore, in order to suppress the decomposition of carbonyl halide, light with a lower energy and a peak wavelength of 300 nm or more can be used.

[0093] The flow rate of the flowing mixed gas in the photoreaction vessel for irradiating the flowing mixed gas with high-energy light is preferably determined in consideration of the internal volume of the photoreaction vessel. For example, when the internal volume of the photoreaction vessel is large, since there is a tendency for the residence time of the mixed gas to become longer, it is preferable to increase the flow rate. On the contrary, when the internal volume is small, it is preferable to adjust the flow rate of the mixed gas to be slower. Specifically, since the internal volume (L) of the photoreaction vessel / the flow rate of the flowing mixed gas (L / second) is equivalent to the residence time (seconds) of the flowing mixed gas in the photoreaction vessel, the flow rate of the flowing mixed gas can be determined based on the required residence time and the internal volume of the photoreaction vessel. In addition, the linear velocity of the flowing mixed gas in the photoreaction vessel can be adjusted to be about 0.001 m / minute or more and 100 m / minute or less. If this linear velocity is 0.001 m / minute or more, the photodecomposition of the carbonyl halide generated from the halomethane by the gas-phase reaction can be more reliably suppressed. If it is 100 m / minute or less, sufficient time for the conversion of the halomethane to the carbonyl halide can be more reliably obtained. This linear velocity can be calculated by dividing the velocity of the mixed gas flowing through the photoreaction vessel by the cross-sectional area inside the photoreaction vessel. When the cross-sectional area inside the photoreaction vessel is not constant, this cross-sectional area can be regarded as the average value of the cross-sectional area of the photoreaction vessel in the moving direction of the flowing mixed gas. This average value can be obtained by dividing the volume inside the photoreaction vessel by the length of the moving direction of the flowing mixed gas inside the photoreaction vessel. As this linear velocity, it is preferably 0.01 m / minute or more. In addition, it is preferably 50 m / minute or less or 20 m / minute or less, more preferably 10 m / minute or less or 5 m / minute or less, and further preferably 1 m / minute or less or 0.5 m / minute or less.

[0094] The temperature when light irradiates the halomethane can be appropriately adjusted within the range where the halomethane can be photo-oxidatively decomposed and the excessive decomposition of the generated carbonyl halide can be suppressed. As the temperature, for example, it can be 35°C or more and 250°C or less. As this temperature, it is preferably 40°C or more or 50°C or more, more preferably 60°C or more or 70°C or more, and further preferably 75°C or more. In addition, it is preferably 200°C or less, more preferably 150°C or less, and further preferably 120°C or less. The temperature can be adjusted by a heater or a heat medium provided in the reactor.

[0095] When irradiating a mixed gas containing halomethane, oxygen, and ozone with light, the mixed gas can be unpressurized, but it can also be pressurized to at least the extent that the mixed gas can pass through the reaction vessel. In addition, by pressurizing the mixed gas, the productivity can also be increased. The gauge pressure of the mixed gas inside the reaction vessel can be adjusted to be 0 MPaG or more and 2 MPaG or less, preferably 1 MPaG or less, and more preferably 0.5 MPaG or less.

[0096] In this step, the halogenated methane is oxidatively photodecomposed to produce a carbonyl halide [X-C(=O)-X (X represents one or more halogenated groups selected from chlorine, bromine, and iodine)]. In addition, not only the carbonyl halide is produced, but also a carbonyl halide-like compound that has the same function as the carbonyl halide can be produced. The carbonyl halide-like compound is also included in the acyl halide of the present invention. Hereinafter, representative examples of the reaction using the carbonyl halide will be described.

[0097] 3. Post-reaction step - Preparation of carbonate compound

[0098] The carbonate compound can be prepared by reacting the carbonyl halide with an alcohol compound.

[0099] The reaction method is not particularly limited. For example, as Figures 1-4 shown, a gas containing the generated carbonyl halide can be blown into the composition containing the alcohol compound. In addition, for example, in the reaction system Figure 4 shown, by irradiating light while blowing oxygen and ozone into the composition containing the halogenated methane and the alcohol compound, the carbonyl halide generated in the composition can immediately react with the alcohol compound, or the alcohol compound and the halogenated methane can be continuously supplied to the gas phase together, and the carbonyl halide generated in the gas phase can immediately react with the alcohol compound.

[0100] A cooler can be provided between the photoreactor and the reactor for reacting with reactants such as the alcohol compound. Preferably, the temperature of the cooler is adjusted so that the generated carbonyl halide can pass through. For example, among the carbonyl halides, the boiling point of phosgene [ClC(=O)Cl] is 8.2 °C. Therefore, when phosgene is generated, the temperature of the cooler is preferably set to 10 °C or higher and lower than room temperature. It should be noted that the carbonyl halide is also called a dihalocarbonyl, and phosgene is also called a dichlorocarbonyl.

[0101] The alcohol compound refers to an organic compound having a hydroxyl group. For example, a monohydric alcohol compound represented by the following formula (I) or a dihydric alcohol compound represented by the following formula (II) can be cited. Hereinafter, the compound represented by formula x may sometimes be simply referred to as "compound x". For example, "the monohydric alcohol compound represented by formula (I)" may sometimes be simply referred to as "monohydric alcohol compound (I)".

[0102] R 1 -OH ··· (I)

[0103] HO-R 2 -OH ··· (II)

[0104] In the formula, R 1 represents a monovalent organic group, and R 2 represents a divalent organic group.

[0105] The organic group is not particularly limited as long as it is inert to the reaction in this process. For example, it may include a C 1-10 aliphatic hydrocarbon group, a C 6-30 aromatic hydrocarbon group, a heteroaryl group that may have substituents, an organic group formed by bonding two or more and five or less C 1-10 aliphatic hydrocarbon groups and a C 6-12 aromatic hydrocarbon group, and an organic group formed by bonding two or more and five or less C 1-10 aliphatic hydrocarbon groups and a heteroaryl group that may have substituents.

[0106] As the C 1-10 aliphatic hydrocarbon group, for example, it may include a C 1-10 linear aliphatic hydrocarbon group, a C 3-10 cyclic aliphatic hydrocarbon group, and an organic group formed by bonding two or more and five or less C 1-10 linear aliphatic hydrocarbon groups and a C 3-10 cyclic aliphatic hydrocarbon group.

[0107] “C 1-10 linear aliphatic hydrocarbon group” means a saturated or unsaturated aliphatic hydrocarbon group having a straight or branched chain with 1 to 10 carbon atoms. For example, as a monovalent C 1-10 linear aliphatic hydrocarbon group, it may include a C 1-10 alkyl group, a C 2-10 alkenyl group, and a C 2-10 alkynyl group.

[0108] As the C 1-10 alkyl group, for example, it may include methyl, ethyl, n-propyl, isopropyl, n-butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, 2,2-dimethylethyl, n-pentyl, n-hexyl, 2-hexyl, 3-hexyl, 4-methyl-2-pentyl, n-heptyl, n-octyl, n-decyl, etc. Preferably a C 2-8 alkyl group, more preferably a C 4-6 alkyl group.

[0109] As the C 2-10 alkenyl group, for example, it may include ethenylene (vinyl), 1-propenyl, 2-propenyl (allyl), butenyl, hexenyl, octenyl, decenyl, etc. Preferably a C 2-8 alkenyl group, more preferably a C 4-6 alkenyl group.

[0110] As the C 2-10 alkynyl group, for example, it may include ethynyl, propynyl, butynyl, hexynyl, octynyl, pentadecynyl, etc. Preferably a C 2-8 alkynyl group, more preferably a C2-6 Alkynyl group.

[0111] “C 3-10 "Cycloaliphatic hydrocarbon group" means a cyclic saturated or unsaturated aliphatic hydrocarbon group having 3 or more and 10 or less carbon atoms. For example, as a monovalent C 3-10 cycloaliphatic hydrocarbon group, C 3-10 cycloalkyl group, C 4-10 cycloalkenyl group, and C 4-10 cycloalkynyl group can be cited.

[0112] As an organic group formed by bonding 2 or more and 5 or less C 1-10 chain aliphatic hydrocarbon groups and C 3-10 cycloaliphatic hydrocarbon groups, for example, C 3-10 monovalent cycloaliphatic hydrocarbon group-C 1-10 divalent chain aliphatic hydrocarbon group, C 1-10 monovalent chain aliphatic hydrocarbon group-C 3-10 divalent cycloaliphatic hydrocarbon group-C 1-10 divalent chain aliphatic hydrocarbon group can be cited.

[0113] “C 6-12 "Aromatic hydrocarbon group" means an aromatic hydrocarbon group having 6 or more and 12 or less carbon atoms. For example, the monovalent C 6-12 aromatic hydrocarbon group is phenyl, indenyl, naphthyl, biphenyl, etc., and phenyl is preferred.

[0114] “C 6-30 "Aromatic hydrocarbon group" means an aromatic hydrocarbon group having 6 or more and 30 or less carbon atoms. For example, as the divalent C 6-30 aromatic hydrocarbon group, for example, in addition to divalent C 6-12 aromatic hydrocarbon groups such as phenylene, indenylene, naphthylene, biphenylene, etc., the alcohol compound (II-1) described later can also be cited.

[0115] "Heteroaryl" means a five-membered aromatic heterocyclic group, a six-membered aromatic heterocyclic group, or a fused-ring aromatic heterocyclic group having at least one heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom. For example, a monovalent 5-membered ring heteroaryl such as pyrrolyl, imidazolyl, pyrazolyl, thienyl, furyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, thiadiazole, etc.; a monovalent 6-membered heteroaryl such as pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, etc.; a monovalent fused-ring aromatic heterocyclic group such as indolyl, isoindolyl, quinolinyl, isoquinolinyl, benzofuryl, isobenzofuryl, benzopyranyl, etc. can be cited.

[0116] As "an organic group formed by bonding 2 or more and 5 or less C 1-10 aliphatic hydrocarbon groups and C 6-12 aromatic hydrocarbon groups", for example, C 6-12 aromatic hydrocarbon group-C1-10 A chain aliphatic hydrocarbon group, C 1-10 A chain aliphatic hydrocarbon group-C 6-12 An aromatic hydrocarbon group, C 1-10 A chain aliphatic hydrocarbon group-C 6-12 An aromatic hydrocarbon group-C 1-10 A chain aliphatic hydrocarbon group and C 6-12 An aromatic hydrocarbon group-C 1-10 A chain aliphatic hydrocarbon group-C 6-12 An aromatic hydrocarbon group, as an "organic group formed by bonding two or more and five or less C 1-10 aliphatic hydrocarbon groups and heteroaryl groups", for example, heteroaryl-C 1-10 A chain aliphatic hydrocarbon group, C 1-10 A chain aliphatic hydrocarbon group-heteroaryl, C 1-10 A chain aliphatic hydrocarbon group-heteroaryl-C 1-10 A chain aliphatic hydrocarbon group and heteroaryl-C 1-10 A chain aliphatic hydrocarbon group-heteroaryl.

[0117] As a substituent that a C 1-10 aliphatic hydrocarbon group can have, for example, one or more substituents selected from a halogen group, a nitro group, and a cyano group can be cited, and a halogen group is preferred. As a C 6-12 substituent that an aromatic hydrocarbon group and a heteroaryl group can have, for example, one or more substituents selected from C 1-6 alkyl, C 1-6 alkoxy, halogen group, nitro group, and cyano group can be cited, and a halogen group is preferred. As the "halogen group", fluorine, chlorine, bromine, and iodine can be cited, and fluorine is preferred.

[0118] In addition, alcohol compounds can also be classified into fluorinated alcohol compounds that must have a fluorine group as a substituent and non-fluorinated alcohols that are not substituted by a fluorine group. The halogen group of the substituent that the non-fluorinated alcohol can have is one or more halogen groups selected from chlorine, bromine, and iodine. In addition, the group "R x " having a fluorine group as a substituent can also be denoted as "R F x ".

[0119] "C 1-6 alkyl" refers to a straight-chain or branched monovalent saturated aliphatic hydrocarbon group having 1 or more and 6 or less carbon atoms. For example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, etc. C 1-4 alkyl is preferred, C 1-2 alkyl is more preferred, and methyl is further preferred.

[0120] "C 1-6"Alkoxy" refers to a straight-chain or branched-chain saturated fatty hydrocarbon oxy group having 1 or more and 6 or less carbon atoms. For example, it is methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, n-pentyloxy, n-hexyloxy, etc., preferably C 1-4 alkoxy, more preferably C 1-2 alkoxy, and even more preferably methoxy.

[0121] The monohydric alcohol compound (I) may be a fluorinated alcohol compound. Examples of the monohydric fluorinated alcohol compound (I) include fluorinated ethanols such as difluoroethanol and trifluoroethanol; and fluorinated propanols such as monofluoropropanol, difluoropropanol, trifluoropropanol, tetrafluoropropanol, pentafluoropropanol, and hexafluoropropanol.

[0122] Examples of the divalent organic group include divalent organic groups corresponding to the exemplified monovalent organic groups. For example, divalent organic groups corresponding to the C 1-10 alkyl group, C 2-10 alkenyl group, and C 2-10 alkynyl group are C 1-10 alkanediyl groups, C 2-10 alkenediyl groups, and C 2-10 alkynediyl groups.

[0123] In addition, the divalent organic group is a divalent (poly)alkylene glycol group -[-O-R 2 -] n -[wherein, R 2 represents C 1-8 alkanediyl, and n represents an integer of 1 or more and 50 or less.].

[0124] In addition, examples of the diol compound (II) include the following diol compound (II-1).

[0125] [Chemical formula 4]

[0126]

[0127] In the formula,

[0128] R 11 and R 12 independently represent H, C 1-6 alkyl, C 1-6 fluoroalkyl, or C 6-12 aromatic hydrocarbon group, or together form a C 1-6 cycloalkyl group that may be substituted by C 3-6 alkyl,

[0129] R 13 and R 14 independently represent H, C 1-6 alkyl, or C 6-12An aromatic hydrocarbon group, when P1 or p2 is an integer of 2 or more, a plurality of R 13 or R 14 may be the same as or different from each other,

[0130] P1 and p2 independently represent an integer of 0 or more and 4 or less.

[0131] As the diol compound (II-1), specifically, for example, 2,2-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 2,2-bis(4-hydroxyphenyl)butane, bis(4-hydroxyphenyl)diphenylmethane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)ethane, bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxy-3-isopropylphenyl)propane, and preferably 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) can be cited.

[0132] The diol compound (II) may be a fluorinated alcohol compound. As the difluorinated alcohol compound (II), for example, fluorinated ethylene glycol; fluorinated propylene glycols such as monofluoropropylene glycol and difluoropropylene glycol; fluorinated butylene glycols such as monofluorobutylene glycol, difluorobutylene glycol, trifluorobutylene glycol, and tetrafluorobutylene glycol; fluorinated pentylene glycols such as monofluoropentylene glycol, difluoropentylene glycol, trifluoropentylene glycol, tetrafluoropentylene glycol, pentafluoropentylene glycol, and hexafluoropentylene glycol; fluorinated hexylene glycols such as monofluorohexylene glycol, difluorohexylene glycol, trifluorohexylene glycol, tetrafluorohexylene glycol, pentafluorohexylene glycol, hexafluorohexylene glycol, heptafluorohexylene glycol, and octafluorohexylene glycol; fluorinated heptylene glycols such as monofluoroheptylene glycol, difluoroheptylene glycol, trifluoroheptylene glycol, tetrafluoroheptylene glycol, pentafluoroheptylene glycol, hexafluoroheptylene glycol, heptafluoroheptylene glycol, octafluoroheptylene glycol, nonafluoroheptylene glycol, and decafluoroheptylene glycol; fluorinated octylene glycols such as monofluoroctylene glycol, difluoroctylene glycol, trifluoroctylene glycol, tetrafluoroctylene glycol, pentafluoroctylene glycol, hexafluoroctylene glycol, heptafluoroctylene glycol, octafluoroctylene glycol, nonafluoroctylene glycol, decafluoroctylene glycol, undecafluoroctylene glycol, and dodecafluoroctylene glycol; fluorinated nonylene glycols such as monofluorononylene glycol, difluorononylene glycol, trifluorononylene glycol, tetrafluorononylene glycol, pentafluorononylene glycol, hexafluorononylene glycol, heptafluorononylene glycol, octafluorononylene glycol, nonafluorononylene glycol, decafluorononylene glycol, undecafluorononylene glycol, dodecafluorononylene glycol, tridecafluorononylene glycol, and tetradecafluorononylene glycol; fluorinated decylene glycols such as monofluorodecylene glycol, difluorodecylene glycol, trifluorodecylene glycol, tetrafluorodecylene glycol, pentafluorodecylene glycol, hexafluorodecylene glycol, heptafluorodecylene glycol, octafluorodecylene glycol, nonafluorodecylene glycol, decafluorodecylene glycol, undecafluorodecylene glycol, dodecafluorodecylene glycol, tridecafluorodecylene glycol, tetradecafluorodecylene glycol, pentadecafluorodecylene glycol, and hexadecafluorodecylene glycol; fluorinated polyethylene glycols such as fluorinated diethylene glycol, fluorinated triethylene glycol, fluorinated tetraethylene glycol, fluorinated pentaethylene glycol, and fluorinated hexaethylene glycol.

[0133] The amount of the alcohol compound used can be appropriately adjusted as long as the reaction proceeds well. Preferably, the molar ratio of the alcohol compound to the generated carbonyl halide is (2 / valence of the alcohol compound) or more and (20 / valence of the alcohol compound) or less. For example, a diol compound having a molar ratio of 1 or more to the generated carbonyl halide can be used, and a monohydric alcohol compound having a molar ratio of 2 or more can be used. By using an excessive amount of the alcohol compound, the carbonate compound can be obtained more effectively. However, since the yield of the carbonyl halide relative to the used halomethane is not constant, preferably, the molar ratio of the alcohol compound to the halomethane is (2 / valence of the alcohol compound) or more and (20 / valence of the alcohol compound) or less. For example, it is preferable that the molar ratio of the diol compound to the halomethane is 1 or more, and the molar ratio of the monohydric alcohol compound to the halomethane is 2 or more. As the above molar ratio of the diol, it is preferably 1.5 or more, more preferably 2 or more, and preferably 10 or less, preferably 5 or less. As the above molar ratio of the monohydric alcohol, it is preferably 2 or more, more preferably 4 or more, and preferably 20 or less, preferably 10 or less.

[0134] To promote the reaction between the carbonyl halide and the alcohol compound, a base can be used. The base is classified into an inorganic base and an organic base. As the inorganic base, for example, carbonates of alkali metals such as lithium carbonate, sodium carbonate, potassium carbonate, and cesium carbonate; carbonates of Group 2 metals such as magnesium carbonate, calcium carbonate, and barium carbonate; bicarbonates of alkali metals such as lithium bicarbonate, sodium bicarbonate, potassium bicarbonate, and cesium bicarbonate; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; hydroxides of Group 2 metals such as magnesium hydroxide and calcium hydroxide; fluoride salts of alkali metals such as lithium fluoride, sodium fluoride, potassium fluoride, and cesium fluoride can be cited. Preferably, carbonates or bicarbonates of alkali metals or Group 2 metals with low hygroscopicity and deliquescence are used, and more preferably carbonates of alkali metals are used. When using an inorganic base, fine substances such as powders can be used, or aqueous solutions can also be used. As the organic base, from the viewpoint of low reactivity of the product of the photoreaction with tetrachloroethylene, for example, tri(C 1-4 alkyl)amines such as trimethylamine, triethylamine, and diisopropylethylamine; tert-butoxides of alkali metals such as sodium tert-butoxide and potassium tert-butoxide; non-nucleophilic organic bases such as diazabicycloundecene, lithium diisopropylamide, lithium tetramethylpiperidine, 1,4-diazabicyclo[2.2.2]octane (DABCO), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,1,3,3-tetramethylguanidine (TMG), and N-methylmorpholine can be used, and low-nucleophilic organic bases such as pyridine or dimethylpyridine can also be used.

[0135] In the oxidative photodecomposition reaction of halogenated methane and the reaction of carbonyl halide with an alcohol compound, hydrogen halides such as hydrogen chloride are by-produced. Bases are effective for capturing such hydrogen halides, but in the case of using a reaction tube with a small diameter such as a coil reaction device, salts of hydrogen halides and bases precipitate, sometimes causing blockage. In such a case, it is preferable to use a base in which the salt of hydrogen halide and the base is an ionic liquid. As the base, for example, organic bases such as imidazole derivatives such as 1-methylimidazole can be mentioned. In addition, a base having a relatively low melting point of its hydrochloride such as pyridine can also be used.

[0136] The amount of the base used can be appropriately adjusted as long as the reaction proceeds well. For example, relative to 1 mol of halogenated methane, it can be 1 mol or more and 10 mol or less.

[0137] The base can be added to the alcohol compound, for example, or can be continuously injected together with the alcohol compound.

[0138] In the case of reacting a carbonyl halide with an alcohol compound, a solvent can be used. The solvent can be added to the composition containing the alcohol compound, for example. As the solvent, for example, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aliphatic hydrocarbon solvents such as n-hexane; aromatic hydrocarbon solvents such as benzene, toluene, xylene, and benzonitrile; ether solvents such as diethyl ether, tetrahydrofuran, and dioxane; nitrile solvents such as acetonitrile; and halogenated hydrocarbon solvents such as dichloromethane and chloroform can be mentioned.

[0139] The temperature for reacting a carbonyl halide with an alcohol compound is not particularly limited and can be appropriately adjusted. For example, it can be 0 °C or higher and 250 °C or lower. As this temperature, it is more preferably 10 °C or higher, further preferably 20 °C or higher, and furthermore, it is more preferably 200 °C or lower or 150 °C or lower, and further preferably 100 °C or lower or 80 °C or lower. However, in the case of not using a base or in the case of using a base and wishing to further promote the reaction, this temperature can be adjusted to a relatively high temperature such as 50 °C or higher or 100 °C or higher.

[0140] The time for reacting a carbonyl halide with an alcohol compound is not particularly limited and can be appropriately adjusted. For example, it is preferably 0.5 hour or more and 50 hours or less. As this reaction time, it is more preferably 1 hour or more, further preferably 5 hours or more, and furthermore, it is more preferably 30 hours or less, and further preferably 20 hours or less. In addition, after the formation of the carbonyl halide is completed, for example, the reaction solution can be continuously stirred until the consumption of the alcohol compound is confirmed.

[0141] According to the reaction of carbonyl halide with an alcohol compound, when a monohydric alcohol compound (I) is used, a chain carbonate compound represented by the following formula (III) is formed, and when a dihydric alcohol compound (II) is used, a polycarbonate compound containing a unit represented by the following formula (IV-1) or a cyclic carbonate compound represented by the following formula (IV-2) is formed. When a dihydric alcohol compound (II) is used, a polycarbonate compound (IV-1) or a cyclic carbonate compound (IV-2) is formed, and their formation ratios mainly depend on the distance between the two hydroxyl groups and the flexibility of the chemical structure in the dihydric alcohol compound (II). Specifically, it can be confirmed through preliminary experiments and the like.

[0142] R 1 -O-C(=O)-O-R 1 (III)

[0143] [-A-R 2 -A-C(=O)-](IV-1)

[0144] [Chemical formula 5]

[0145]

[0146] According to the present invention, the polymerization reaction can be carried out very effectively, and a polycarbonate compound with a high molecular weight can be obtained. For example, the polystyrene-converted weight-average molecular weight of the polycarbonate compound obtained by the method of the present invention analyzed by gel permeation chromatography (GPC) is preferably 10,000 or more and 1,000,000 or less, and the number-average molecular weight is preferably 5,000 or more and 500,000 or less.

[0147] 4. Post-reaction process - Preparation of haloformate

[0148] In the above method for preparing a carbonate compound, by not using a base and making the molar ratio of the alcohol compound to the halogenated methane less than 1, a haloformate is mainly obtained. As this molar ratio, it is preferably 0.9 or less, more preferably 0.8 or less. Depending on the conditions, both a carbonate compound and a haloformate can be obtained. As the alcohol compound, the above monohydric alcohol compound (I) can be used. In addition, a fluorinated haloformate is obtained from the fluorinated monohydric alcohol compound (I), and a non-fluorinated haloformate is obtained from the non-fluorinated monohydric alcohol compound (I).

[0149] 5. Post-reaction process - Preparation of isocyanate compound

[0150] An isocyanate compound can be prepared by reacting a carbonyl halide with a primary amine compound. The isocyanate compound is useful as a raw material for a urethane compound or a carbamate compound, etc. As a reaction mode, in the above method for preparing a carbonate compound, a primary amine compound can be used in place of an alcohol compound except for the following aspects.

[0151] The primary amine compound is not particularly limited as long as it is a compound having one or more amino groups (-NH2 groups). For example, a primary amine compound (V): R 3 -(NH2) m can be used. In the formula, R 3 represents an m-valent organic group, and m represents an integer of 1 or more and 6 or less, preferably 5 or less, 4 or less, or 3 or less, more preferably 1 or 2, and still more preferably 2.

[0152] In the organic group R 3 , examples of the monovalent organic group include the same groups as the monovalent organic group R 1 in the above method for preparing a carbonate compound, and examples of the divalent organic group include the same groups as the divalent organic group R 2 . In addition, as the trivalent or higher organic group, a trivalent or higher organic group corresponding to the exemplified monovalent organic group R 1 can be cited. For example, the trivalent organic groups corresponding to the monovalent organic groups of C 1-10 alkyl, C 2-10 alkenyl, and C 2-10 alkynyl are C 1-10 alkanetriyl, C 2-10 alkenetriyl, and C 2-10 alkynetriyl.

[0153] By reacting a carbonyl halide with a primary amine compound (V), an isocyanate compound (VI): R 3 -(N=C=O) m is obtained. However, the generated R 3 -(N=C=O) m may react with the primary amine compound (V) to form a urea compound R 3 -[NH-C(=O)-NH-R 3 m . To suppress this reaction, it is preferable to adjust the molar ratio of the primary amine compound (V) to methyl halide to 1 or less, or use a salt as the primary amine compound (V), or not use a base. In addition, by dissolving the generated carbonyl halide in a solvent to prepare a carbonyl halide solution and adding the primary amine compound (V) or its solution to this solution to keep the molar ratio of the carbonyl halide to the primary amine compound (V) greater than 1, an isocyanate compound can be effectively prepared.

[0154] ​When the target compound is an isocyanate compound, it is preferable that the molar ratio of the primary amine compound (V) to the generated carbonyl halide is 1 or less. However, since it is sometimes difficult to predict the exact amount of carbonyl halide generated, it is preferable that the molar ratio of the primary amine compound (V) to the used methyl halide is less than 1. As this molar ratio, it is preferably 0.5 or less, more preferably 0.2 or less. Additionally, it is preferably 0.001 or more, more preferably 0.05 or more. On the other hand, when the target compound is a urea compound, as this ratio, it is preferably 2 or more, more preferably 4 or more. Additionally, it is preferably 20 or less, more preferably 15 or less.

[0155] When the target compound is an isocyanate compound, it is difficult for the isocyanate compound to react with an amine salt. Therefore, it is preferable to use a salt as the primary amine compound (V). As the said salt, for example, inorganic acid salts such as hydrochloride, hydrobromide, hydroiodide, sulfate, nitrate, perchlorate, phosphate, etc.; organic acid salts such as oxalate, malonate, maleate, fumarate, lactate, malate, citrate, tartrate, benzoate, trifluoroacetate, acetate, methanesulfonate, p-toluenesulfonate, trifluoromethanesulfonate, etc. can be cited.

[0156] The temperature for the reaction of the carbonyl halide compound and the primary amine compound is preferably set lower than the reaction temperature with the alcohol compound to maintain, for example, the liquid state of the carbonyl halide compound. For example, this reaction temperature can be set to 15°C or lower, preferably 10°C or lower, more preferably 5°C or lower, and further preferably 2°C or lower. There is no particular limitation on the lower limit of this temperature. For example, as this temperature, it is preferably -80°C or higher, more preferably -20°C or higher or -15°C or higher.

[0157] When the target compound is an isocyanate compound and a base is used, as the base, it is preferable to select one or more bases from heterocyclic aromatic amines and non-nucleophilic strong bases. A heterocyclic aromatic amine refers to a compound containing at least one heterocycle and having at least one amine functional group other than -NH2. As heterocyclic aromatic amines, for example, pyridine, α-methylpyridine, β-methylpyridine, γ-methylpyridine, 2,3-dimethylpyridine, 2,4-dimethylpyridine, 2,6-dimethylpyridine, 3,5-dimethylpyridine, 2-chloropyridine, 3-chloropyridine, 4-chloropyridine, 2,4,6-trimethylpyridine, 4-dimethylaminopyridine, and other pyridine and its derivatives, etc. can be cited.

[0158] "Non-nucleophilic strong base" refers to a base in which the nucleophilicity of the lone pair of electrons on the nitrogen atom is weak due to steric hindrance but has strong basicity. For example, triethylamine, N,N-diisopropylethylamine, tripropylamine, triisopropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, tridecylamine, tris(dodecyl)amine, triphenylamine, tribenzylamine, N,N-diisopropylethylamine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), and 1,1,3,3-tetramethylguanidine (TMG) can be listed. In addition, bases with relatively high basicity can also be used. For example, as a base with a basicity (pK BH+ ) of 20 or more in acetonitrile, TBD (pK BH+ : 25.98), MTBD (pK BH+ : 25.44), DBU (pK BH+ : 24.33), DBN (pK BH+ : 23.89), and TMG (pK BH+ : 23.30) can be used.

[0159] In addition, as a base, general organic amines such as trimethylamine, dimethylethylamine, diethylmethylamine, N-ethyl-N-methylbutylamine, and 1-methylpyrrolidine can also be used.

[0160] In addition, when the target compound is a urea compound, it is preferable that the molar ratio of the primary amine compound to the halogenated methane or the generated carbonyl halide exceeds 1. As this molar ratio, it is preferably 1.5 or more, and more preferably 2 or more.

[0161] 6. Post-reaction process - Preparation of carbamoyl halide compounds

[0162] By reacting a carbonyl halide with a secondary amine compound, a carbamoyl halide compound can be prepared. The carbamoyl halide compound is useful as a synthetic intermediate for carbamates, such as carbamate compounds having insecticidal properties, and other physiologically active substances such as pharmaceuticals and pesticides. As a reaction method, in the above method for preparing an isocyanate compound, a secondary amine compound can be used instead of the primary amine compound.

[0163] The secondary amine compound is not particularly limited as long as it is a compound having one or more secondary amino groups (-NHR group). For example, the secondary amine compound (XI): R 21 -NH-R 22 . In the formula, R 21 and R 22Independently represents a monovalent organic group, and examples thereof include the monovalent organic group R in the preparation method of the above-mentioned carbonate compound 1 The same group, preferably C 1-10 alkyl group.

[0164] By reacting a carbonyl halide with a secondary amine compound (XI), a carbamoyl halide compound (XII) is obtained: R 21 R 22 N-C(=O)-X (wherein X is one or more halogen substituents selected from chlorine, bromine, and iodine). However, the generated R 21 R 22 N-C(=O)-X may react with the secondary amine compound (XI) to form a urea compound R 21 R 22 N-C(=O)-NR 21 R 22 . To suppress this reaction, it is preferable to adjust the amount of the secondary amine compound (XI) used to be low. For example, the molar ratio of the secondary amine compound (XI) to methane is adjusted to 1 or less, or no base is used. In addition, by dissolving the generated carbonyl halide in a solvent to prepare a carbonyl halide solution and adding the secondary amine compound (XI) or its solution to this solution to keep the molar ratio of the carbonyl halide to the secondary amine compound (XI) greater than 1, the carbamoyl halide compound can be effectively prepared.

[0165] When the target compound is a carbamoyl halide compound, it is preferable to adjust the amount of the secondary amine compound (XI) used to be low. For example, it is preferable that the molar ratio of the secondary amine compound (XI) to the generated carbonyl halide is 1 or less. However, it is sometimes difficult to predict the accurate amount of carbonyl halide generated. Therefore, it is preferable that the molar ratio of the secondary amine compound (XI) to the methane used is less than 1. As this molar ratio, it is preferably 0.5 or less, more preferably 0.2 or less. Additionally, it is preferably 0.001 or more, more preferably 0.05 or more. On the other hand, when the target compound is a urea compound, as this ratio, it is preferably 2 or more, more preferably 4 or more. Additionally, it is preferably 20 or less, more preferably 15 or less.

[0166] The temperature for the reaction of the carbonyl halide compound with the secondary amine compound (XI) is preferably set to be lower than the reaction temperature with the alcohol compound to maintain, for example, the liquid state of the carbonyl halide compound. For example, this reaction temperature can be set to 15°C or lower, preferably 10°C or lower, more preferably 5°C or lower, and further preferably 2°C or lower. The lower limit of this temperature is not particularly limited. For example, as this temperature, it is preferably -80°C or higher, more preferably -20°C or higher or -15°C or higher.

[0167] When the target compound is a carbamoyl halide compound and a base is used, as the base, it is preferable to use one or more bases selected from the heterocyclic aromatic amines and non-nucleophilic strong bases exemplified in the preparation conditions of the above-mentioned isocyanate compounds. In addition, when the target compound is a urea compound, it is preferable that the molar ratio of the secondary amine compound to methane or the generated carbonyl halide exceeds 1. As this molar ratio, it is preferably 1.5 or more, more preferably 2 or more.

[0168] 7. Post-reaction process - Preparation of NCA

[0169] In the above method for preparing a carbonate compound, by using an amino acid compound (VII) instead of an alcohol compound, an amino acid-N-carboxylic anhydride (VIII) (NCA) can also be prepared.

[0170] [Chemical formula 6]

[0171]

[0172] In the formula,

[0173] R 4 represents an amino acid side chain group in which the reactive group is protected,

[0174] R 5 represents H or P 1 -[[-NH-CHR 6 -C(=O)-]] l -, in the formula, R 6 represents an amino acid side chain in which the reactive group is protected, P 1 represents a protecting group for the amino group, l represents an integer of 1 or more, and when l is an integer of 2 or more, a plurality of R 6 may be the same as or different from each other.

[0175] 8. Post-reaction process - Preparation of Vilsmeier reagent

[0176] By reacting a carbonyl halide with an amide compound (IX), a Vilsmeier reagent (X) can be prepared. In the preparation of the Vilsmeier reagent, the amide compound (IX) is used instead of the alcohol compound and no base is used. Other than this, it can be carried out in the same manner as the above method for preparing the carbonate compound.

[0177] [Chemical formula 7]

[0178]

[0179] In the formula,

[0180] R 7 represents a hydrogen atom, a C 1-6 alkyl group or a C 6-12 aryl hydrocarbon group which may have a substituent,

[0181] R 8 and R 9 independently represent C 1-6 alkyl or C aromatic hydrocarbon group which may have substituents 6-12 In addition, R 8 and R 9 may together form a ring structure having 4 or more and 7 or less members,

[0182] X represents a halogenated group selected from chlorine, bromine and iodine,

[0183] Y− represents a counter anion.

[0184] C 6-12 The substituents that the aromatic hydrocarbon group may have are not particularly limited as long as they do not hinder the reaction of the present invention. For example, examples thereof include one or more substituents selected from C 1-6 alkyl, C 1-6 alkoxy, halogenated group, nitro and cyano. The number of substituents is not particularly limited as long as substitution is possible. For example, it can be set to 1 or more and 5 or less, preferably 3 or less, more preferably 2 or less, and further preferably 1. When the number of substituents is 2 or more, the substituents may be the same as or different from each other.

[0185] As R 8 and R 9 The ring structure having 4 or more and 7 or less members formed together with the nitrogen atom, for example, includes pyrrolidinyl, piperidinyl, and morpholinyl.

[0186] As specific amide compounds (IX), for example, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), N-methyl-N-phenylformamide, N-methylpyrrolidone (NMP), 1,3-dimethylimidazolidinone (DMI), tetramethylurea, tetraethylurea, tetrabutylurea, etc. are exemplified. From the viewpoints of versatility, cost, etc., DMF is preferred.

[0187] As Y in formula (X) - , chloride ion, bromide ion and iodide ion derived from halogenated methane can be exemplified, but are not particularly limited.

[0188] The amount of the amide compound used can be appropriately adjusted as long as the reaction proceeds well. For example, relative to 1 mL of halogenated methane, it can be set to 0.1 mol or more and 100 mol or less.

[0189] In the case of reacting an acyl halide with an amide compound, a solvent can be used. For example, the solvent can be added to the composition containing the amide compound. Examples of the solvent include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as ethyl acetate; aliphatic hydrocarbon solvents such as n-hexane; aromatic hydrocarbon solvents such as benzene, toluene, xylene, and benzonitrile; ether solvents such as diethyl ether, tetrahydrofuran, and dioxane; and nitrile solvents such as acetonitrile.

[0190] The temperature for reacting the carbonyl halide with the amide compound is not particularly limited and can be appropriately adjusted. For example, it can be set to be 0°C or higher and 120°C or lower. As this temperature, it is more preferably 10°C or higher, further preferably 20°C or higher. Additionally, it is more preferably 100°C or lower, further preferably 80°C or lower or 50°C or lower.

[0191] The time for reacting the acyl halide with the amide compound is not particularly limited and can be appropriately adjusted. For example, it is preferably 0.5 hours or longer and 50 hours or shorter. As this reaction time, it is more preferably 1 hour or longer, further preferably 5 hours or longer, and more preferably 30 hours or shorter, further preferably 20 hours or shorter. Additionally, after the formation of the carbonyl halide is completed, for example, the reaction solution can also be continuously stirred until the consumption of the amide compound is confirmed.

[0192] Through the Vilsmeier-Haack reaction using the Vilsmeier reagent, an aromatic compound having an active group can be aldehydized or ketonized. Additionally, it is known that the Vilsmeier reagent converts the carboxyl group of a carboxylic acid compound into a halocarbonyl group. Furthermore, by reacting a compound containing a hydroxyl group with the Vilsmeier reagent, a formate ester is obtained.

[0193] An aromatic compound having an active group (hereinafter referred to as "active aromatic compound") is an aromatic compound activated by substituents or the like. For example, an amino group or a hydroxyl group containing an alkylamino substituted by an alkyl group strongly activates the aromatic compound. Additionally, an alkylcarbonylamino (-N(C=O)R), an alkylcarbonyloxy (-O(C=O)R), an ether group (-OR), an alkyl group (-R) (R represents an alkyl group, preferably C 1-6 alkyl), and an aromatic group also activate the aromatic compound. Hereinafter, these substituents are referred to as activating groups. Additionally, compounds such as anthracene in which an aromatic ring is condensed and the conjugated system is expanded are also activated and are aldehydized or ketonized by the Vilsmeier reagent. The π electrons at the activated site react electrophilicly with the Vilsmeier reagent, thereby being aldehydized or ketonized.

[0194] The active aromatic compound is not particularly limited as long as it is activated and aldehyde-formed or ketone-formed by the Vilsmeier reagent. For example, benzene, naphthalene, etc. substituted with the above-mentioned activating groups, etc. C 6-12 Aromatic hydrocarbons; Condensed aromatic hydrocarbons such as phenanthrene and anthracene that can be substituted with the above-mentioned activating groups; 5-membered ring heteroaryls such as pyrrole, imidazole, pyrazole, thiophene, furan, oxazole, isoxazole, thiazole, isothiazole, and thiadiazole that can be substituted with the above-mentioned active groups; 6-membered ring heteroaryls such as pyridine, pyrazine, pyrimidine, and pyridazine that can be substituted with the above-mentioned activating groups; Condensed heteroaryls such as indole, isoindole, quinoline, isoquinoline, benzofuran, isobenzofuran, and chromene that can be substituted with the above-mentioned activating groups. In addition, for unsubstituted furan, thiophene, etc., there are no reported examples of aldehyde formation or ketone formation in the conventional Vilsmeier-Haack reaction, but according to the method of the present invention, aldehyde formation or ketone formation of the carbon adjacent to the hetero element can be achieved.

[0195] The active group-containing aromatic compound, carboxylic acid compound, and hydroxyl group-containing compound as the substrate compound for the above reaction can be added to the reaction solution after blowing the carbonyl halide-containing gas into the composition containing the amide compound, or can be added to the reaction solution before blowing the carbonyl halide-containing gas into the composition containing the amide compound or during the blowing process.

[0196] The usage amounts of the active group-containing aromatic compound, carboxylic acid compound, and hydroxyl group-containing compound can be appropriately adjusted. For example, relative to the amide compound, it can be 0.1 times mole or more and 1.0 times mole or less.

[0197] In addition, the Vilsmeier reagent is also useful for obtaining carboxylic acid halides from carboxylic acid compounds. The Vilsmeier reagent obtained by halogenating the carboxylic acid compound is restored to an amide compound. If an alcohol compound is reacted with the obtained carboxylic acid halide, an ester compound can be obtained, and if a carboxylic acid is reacted with the obtained carboxylic acid halide, a carboxylic anhydride can be obtained. In addition, if a carboxylic acid compound and a base are used instead of the amide compound, it can be considered that the carboxylic acid compound anionized by the base is directly converted into a carboxylic acid halide through the carbonyl halide. This carboxylic acid halide can also be used for the preparation of an ester compound or a carboxylic anhydride.

[0198] 9. Post-treatment process

[0199] Since many carbonyl halides are harmful, it is preferred not to allow the generated carbonyl halide to leak to the outside of the system. For example, as Figures 1-4 shown, it is preferred to introduce the gas phase discharged from the reaction vessel where the generated carbonyl halide reacts into an alcohol trap, and then introduce the gas phase discharged from the alcohol trap into an alkaline trap. The alcohol trap can be cooled to, for example, -80 °C or higher and about 50 °C or lower within the range where the used alcohol does not solidify. In addition, for the alkaline trap, an aqueous sodium hydroxide solution or a saturated aqueous sodium bicarbonate solution can be used, for example.

[0200] When the compound obtained from the carbonyl halide is relatively unstable, for example, when the obtained compound is an isocyanate compound, another reaction matrix compound can be added to the reaction solution of the carbonyl halide reaction. Or, when the compound obtained from the carbonyl halide is relatively stable, such as a carbonate compound, the target compound can be refined from the reaction solution. For example, a water-insoluble organic solvent such as chloroform and water can be added to the reaction solution for liquid separation. After drying the organic phase with anhydrous sodium sulfate, anhydrous magnesium sulfate, etc., it is concentrated under reduced pressure, and the organic phase is further purified by chromatography or the like.

[0201] This application claims the benefit of priority based on Japanese Patent Application No. 2022-203823 filed on December 21, 2022. The entire contents of the specification of Japanese Patent Application No. 2022-203823 filed on December 21, 2022 are incorporated herein by reference.

[0202] Examples

[0203] Hereinafter, the present invention will be described more specifically by way of examples. However, the present invention is of course not limited to the following examples, and can of course be appropriately modified and implemented within the scope that can conform to the gist of the foregoing and following, and they are all included in the technical scope of the present invention.

[0204] Example 1: Preparation of Carbonyl Chloride

[0205] [Chemical Formula 8]

[0206]

[0207] Use Figure 1 The flow photoreaction system schematically shown in [description] is used to perform the photooxidation of ozone of chloroform containing 10 ppm of pentene as a stabilizer.

[0208] Chloroform is delivered from an injection pump and merged with an ozone-oxygen mixed gas generated by an ozone gas generator (“PZH-05N”, manufactured by KOFLOC Corporation). They are mixed in an arbitrary ratio within a PTFE tube, and then passed through a coil heater heated to 120 °C to prepare a chloroform-ozone-oxygen mixed gas, which is fed into a flow-through photoreactor. The flow-through photoreactor (volume: 700 mL, length: 180 mm) is composed of the following heating plate (“HTP452AB”, manufactured by ADVANTEC Corporation). In a cylindrical borosilicate glass container (Φ80 mm), a quartz glass inner tube (Φ30 mm) is installed, and a 20 W low-pressure mercury lamp (“SUL-20P”, manufactured by SEN Special Light Source Corporation, luminous part length: 130 mm) is installed inside the inner tube, and the bottom is heated to 100 °C. In addition, the wavelength range of the lamp light is 185 - 600 nm, the peak wavelengths are 184.9 nm and 253.7 nm, and the illuminance of the light with a wavelength of 185 nm at a position 5 mm away from the lamp is 2.00 - 2.81 mW / cm 2 , and the illuminance of the light with a wavelength of 254 nm at the same position is 5.60 - 8.09 mW / cm 2 . As shown in Table 1, the flow rates of chloroform and ozone gas are adjusted, and the residence time of the reaction gas in the flow-through photoreactor is controlled at 3.4 minutes to study the ozonation photooxidation reaction of chloroform. The gas products generated in this system are blown into 1-butanol contained in the first reaction vessel to obtain a mixed product of chloroformate and carbonate. The gas from the first reaction vessel is similarly added to the second reaction vessel containing 1-butanol. The reaction liquids in the first reaction vessel and the second reaction vessel are analyzed to determine the production amounts of ethyl chloroformate, dibutyl carbonate, and phosgene. The results are shown in Table 1. It should be noted that the production amount of phosgene is calculated assuming that all the generated phosgene reacts with 1-butanol.

[0209] [Table 1]

[0210]

[0211] Example 2: Preparation of Phosgene

[0212] Using Figure 2 the flow-through photoreaction system schematically shown in

[0213] Chloroform was delivered from an injection pump, merged with the ozone-oxygen mixed gas generated by an ozone gas generator (“PZH-05N”, manufactured by KOFLOC Corporation), mixed within a PTFE tube, and passed through a coil heater heated to 120 °C to prepare a chloroform-ozone-oxygen mixed gas, which was then fed into a flow photoreactor. The flow photoreactor consisted of a borosilicate glass container (outer dimensions: 250 mm × 400 mm × 50 mm, plate thickness: 3.3 mm, internal volume: 4157 cm 3 ), an LED lamp (manufactured by Polarstar Corporation, peak wavelength: 365 nm, 30 W, LED (14 cm × 18 cm) × 2 units), and a heating plate heated to 100 °C (“HTP452AB” manufactured by ADVANTEC Corporation). Additionally, the illuminance of the light at a position 5 mm away from the lamp was 54.7 - 54.4 mW / cm 2 . The flow rates of chloroform and ozone gas were adjusted to control the residence time of the reaction gas in the flow photoreactor at 35 minutes, and the ozone photooxidation reaction of chloroform was studied. The gas products generated in this system were blown into 1-butanol contained in a first reaction vessel to obtain a mixed product of chloroformate and carbonate. The gas from the first reaction vessel was similarly added to a second reaction vessel containing 1-butanol. The reaction liquids in the first and second reaction vessels were analyzed to determine the production amounts of ethyl chloroformate, dibutyl carbonate, and phosgene.

[0214] In addition, for comparison, the experiment was conducted in the same manner except that ozone was not supplied.

[0215] The results are shown in Table 2.

[0216] [Table 2]

[0217]

[0218] As shown in the results of Table 2, chloroform containing pentene (2-pentene) as a stabilizer was hardly photooxidized under irradiation with visible light (365 nm).

[0219] In contrast, when ozone gas was used in addition to oxygen, even chloroform containing pentene as a stabilizer was photooxidized, and phosgene was produced in a high yield of 95%.

[0220] It should be noted that 1 1H NMR experiments confirmed that pentene (2-pentene) decomposed through reaction with ozone, thereby providing acetaldehyde and propionaldehyde.

[0221] Example 3: Preparation of Phosgene

[0222] Using Figure 3The flow photoreaction system schematically shown below is used to carry out the photo-oxidation of chloroform with ozone. As chloroform, chloroform containing pentene as a stabilizer, chloroform from which the stabilizer has been removed, and chloroform that has been pretreated with ozone to decompose pentene are used.

[0223] Chloroform is delivered from a syringe pump and merged with the ozone-oxygen mixed gas generated by an ozone gas generator (“PZH-05N”, manufactured by KOFLOC Co., Ltd.). The mixture is then mixed inside a PTFE tube, passed through a coil heater heated to 120 °C to prepare a chloroform-ozone-oxygen mixed gas, which is then fed into a flow photoreactor. The flow photoreactor consists of a PFA tube (inner diameter: 0.2 cm, outer diameter: 0.3 cm, length: 1940 cm, volume: 61.0 cm 3 ), two LED lamps (manufactured by Polarstar Co., Ltd., peak wavelength: 365 nm, 30 W, LED (14 cm × 18 cm)), and a heating plate heated to 100 °C (“HTP452AB”, manufactured by ADVANTEC Co., Ltd.). Additionally, the illuminance of the light at a position 5 mm away from the lamp is 54.7 - 54.4 mW / cm 2 . The flow rates of chloroform and ozone gas are adjusted to control the residence time of the reaction gas in the flow photoreactor to 1.5 minutes, and the photo-oxidation reaction of chloroform with ozone is studied. The gaseous products generated in this system are blown into 1-butanol contained in a first reaction vessel to obtain a mixed product of chloroformate and carbonate. The gas from the first reaction vessel is similarly added to a second reaction vessel containing 1-butanol. The reaction liquids in the first and second reaction vessels are analyzed to determine the amounts of ethyl chloroformate, dibutyl carbonate, and phosgene formed.

[0224] In addition, for comparison, an LED lamp with a peak wavelength of 405 nm is used, or no light is irradiated, and the experiment is carried out in the same way otherwise. Additionally, the illuminance of the light at a position 5 mm away from the lamp is 31.6 - 32.4 mW / cm 2 .

[0225] The results are shown in Table 3.

[0226] [Table 3]

[0227]

[0228] As shown in the results of Table 3, chloroform containing pentene (2-pentene) as a stabilizer is not photo-oxidized by irradiation with only oxygen and visible light (365 nm) without using ozone.

[0229] Chloroform without a stabilizer or chloroform in which the stabilizer has been decomposed by ozone pretreatment is somewhat photo-oxidized even by irradiation with only visible light, but its conversion efficiency is insufficient.

[0230] In addition, chloroform containing a stabilizer hardly undergoes oxidative decomposition without light irradiation.

[0231] In contrast, when ozone is added to oxygen, the yield is significantly increased, and when the proportion of ozone increases, the yield further increases. Phosgene can also be prepared well from chloroform containing a stabilizer by using ozone in combination.

[0232] However, when using an LED lamp with a longer irradiation light wavelength of 405 nm, the yield decreases somewhat. In addition, the relatively low conversion efficiency compared to other examples is considered to be due to the short residence time of the gas in the reactor, which is as short as 1.5 minutes.

[0233] Example 4: Preparation of Phosgene

[0234] Use Figure 4 The flow photoreaction system schematically shown in

[0235] was used to carry out the ozonation photocatalysis of chloroform containing about 10 ppm pentene as a stabilizer. Liquid chloroform was added to a 1 L two-necked eggplant-shaped flask, heated and stirred at 60 °C, and a mixed gas of ozone-oxygen generated by an ozone gas generator (“PZH-05N”, manufactured by KOFLOC Co., Ltd.) was blown into the liquid chloroform through a PTFE tube (inner diameter: 0.2 cm, outer diameter: 0.3 cm), and the flask was irradiated with light. The flow photoreactor consists of this eggplant-shaped flask equipped with a condenser for cooling (0 °C), a magnetic stirrer, an LED lamp (manufactured by Polarstar Co., Ltd., 365 nm, 30 W, LED (14 cm × 18 cm) × 1) and an aluminum block bath. By adjusting the flow rate of the ozone gas and controlling the residence time of the gas in the reactor as shown in Table 4, the ozonation photocatalysis reaction of chloroform was studied. The gas product generated in this system was blown into 1-butanol contained in a two-necked eggplant-shaped flask to obtain a mixed product of chloroformate and carbonate. The mixed product was analyzed to determine the production amounts of ethyl chloroformate, dibutyl carbonate and phosgene. The results are shown in Table 4. In addition, the results in Table 4 are the average values calculated from a 2-hour reaction.

[0236] [Table 4]

[0237]

[0238] As shown in the results of Table 4, when only oxygen is supplied to the reaction system without supplying ozone, phosgene cannot be obtained sufficiently, but by supplying ozone in addition to oxygen, the yield of phosgene can be greatly improved.

[0239] Example 5: Preparation of Diphenyl Carbonate

[0240] [Chemical Formula 9]

[0241]

[0242] At a flow rate of 16.8 mL / min Figure 3 A mixed gas of ozone: oxygen = 16 vol%: 84 vol% is supplied to the schematically represented photoreaction system. In addition, chloroform containing pentene as a stabilizer is injected at a flow rate of 50.3 μL / min, vaporized by a heater, and mixed with the ozone-oxygen mixed gas to prepare a mixed gas of ozone-oxygen-chloroform. The ozone-oxygen-chloroform mixed gas is continuously fed to the flow photoreaction device and irradiated with light having a peak wavelength of 365 nm at 100°C. In addition, a solution of phenol (9.411 g, 100 mmol) and pyridine (12.07 mL, 150 mmol) dissolved in dichloromethane (64 mL) is placed in a two-necked flask, and the gas obtained from the flow photoreaction device is blown in for 2 hours while stirring at room temperature. 2M hydrochloric acid is added to the reaction solution for liquid separation, and the organic phase is washed with distilled water and dried over anhydrous sodium sulfate. The solvent was distilled off from the organic phase under reduced pressure using an evaporator, and the obtained residue was dried in vacuo at 80°C for 3 hours to obtain the target compound (9.57 g, 44.7 mmol) as a white solid. The isolated yield relative to the raw material phenol was 89%.

[0243] Ozone may oxidize phenol and color it brown, but such coloration was not confirmed in this reaction. According to visual observation, the diphenyl carbonate prepared using ozone was less colored than the diphenyl carbonate prepared in the same manner except that only oxygen was used. The mechanism is unknown, but it may be due to the decolorization effect of ozone.

[0244] Example 6: Preparation of polycarbonate

[0245] [Chemical formula 10]

[0246]

[0247] At a flow rate of 16.8 mL / min Figure 3Ozone is supplied in a mixed gas of ozone:oxygen = 16 vol%:84 vol% in a schematically represented photoreaction system. In addition, chloroform containing pentene as a stabilizer is injected at a flow rate of 50.3 μL / min, vaporized by a heater, and mixed with the ozone-oxygen mixed gas to prepare an ozone-oxygen-chloroform mixed gas. The ozone-oxygen-chloroform mixed gas is continuously fed into a flow photoreaction apparatus and irradiated with light having a peak wavelength of 365 nm at 100 °C. In addition, a solution prepared by dissolving bisphenol A (11.41 g, 50 mmol) and pyridine (20.12 mL, 250 mmol) in dichloromethane (128 mL) is added to a two-necked flask, and while stirring at room temperature, the gas obtained from the flow photoreaction apparatus is blown in for 2 hours. Then, stirring is further continued at room temperature for 2 hours. 2M hydrochloric acid is added to the reaction solution for liquid separation, the organic phase is washed with distilled water, and dried over anhydrous sodium sulfate. The solvent is distilled off under reduced pressure from the organic phase using an evaporator, n-hexane is added, the resulting precipitate is filtered off, and vacuum dried at 80 °C for 2 hours to obtain the target compound as a white solid (9.18 g, 36.1 mmol). The separation yield relative to the raw material bisphenol A is 72%.

[0248] In addition, the soluble portion of the obtained polycarbonate was analyzed by gel permeation chromatography (GPC), and the molecular weight was determined by conversion to standard polystyrene. The apparatus, column, and measurement conditions used for GPC are as follows.

[0249] Apparatus: "LC-2000" manufactured by JASCO Corporation

[0250] Pump: "4-solvent low-pressure gradient pump PU-2089" manufactured by JASCO Corporation

[0251] Detector: "Differential refractive index detector RI-4030" manufactured by JASCO Corporation

[0252] Guard column: "TSKgel GuardcolumnH HR -H" × 1 piece, manufactured by Tosoh Corporation

[0253] Analysis column: "TSKgelG5000H HR " × 1 piece + "TSKgelG4000HHR" × 1 piece, manufactured by Tosoh Corporation Solvent: HPLC grade THF

[0254] Sample pretreatment: ADVANTEC DISMIC-03JP (pore size 0.5 μm)

[0255] Sample injection volume: 25 μL

[0256] Sample concentration: 0.2 w / v% in HPLC grade THF solution

[0257] Solvent flow rate: 1.0 mL / min

[0258] Measured temperature: 40 °C

[0259] Standard polystyrene: "Polystyrene standard for GPC calibration" prepared by ChemcoPlus

[0260] The results are shown below.

[0261] [Table 5]

[0262] <![CDATA[M w > <![CDATA[M n > <![CDATA[M w / M n > 306,500 133,300 2.30

[0263] Ozone may oxidize phenol and color it brown, but such coloring was not confirmed in this reaction. According to visual observation, the polycarbonate made using ozone has less coloring than the polycarbonate made in the same manner except using only oxygen. Therefore, according to the method of the present invention, polycarbonate with higher transparency can be prepared.

[0264] In addition, most of the polycarbonate obtained by the method of the present invention is insoluble in organic solvents, and the molecular weight of the soluble part is much larger than that of the polycarbonate obtained by the same method except using only oxygen. Therefore, by using ozone in addition to oxygen, not only the oxidative photodegradation reaction of chloroform, but also the polymerization reaction may be accelerated.

[0265] Example 7: Preparation of Isocyanate

[0266] [Chemical formula 11]

[0267]

[0268] Supply a mixed gas of ozone:oxygen = 16 vol%:84 vol% to the Figure 3 schematically shown photoreaction system at a flow rate of 16.8 mL / min. In addition, inject chloroform containing pentene as a stabilizer at a flow rate of 50.3 μL / min, vaporize it with a heater, and mix it with the ozone-oxygen mixed gas to prepare a mixed gas of ozone-oxygen-chloroform. Continuously feed the ozone-oxygen-chloroform mixed gas into a flow-through photoreactor and irradiate it with light having a peak wavelength of 365 nm at 100 °C. In addition, add dichloromethane (100 mL) to a two-necked flask, and while stirring at 0 °C, blow in the gas obtained from the flow-through photoreactor for 1 hour or 2 hours.

[0269] Cut off the power supply of the LED lamp, stop the injection of chloroform, and under normal indoor lighting, inject a dichloromethane solution of the amine or diamine shown in Table 6 into the above dichloromethane solution. Then, add 5 times the molar amount of pyridine of the amino group of the added amine or diamine and stir at 0 °C for 1 hour.

[0270] Add 1,2-dichloroethane as an internal standard to the reaction solution, and use1 Analysis was carried out by HNMR to confirm that the target compound isocyanate was produced at a yield of 96% or more. The results are shown in Table 6. It should be noted that the conversion efficiency in Table 6 is relative to the raw material amine or diamine used.

[0271] [Table 6]

[0272]

[0273] In a similar reaction using only oxygen, pyridine caused coloring and the reaction solution turned brown. However, when ozone was used in addition to oxygen, no coloring occurred and the reaction solution containing the product was colorless and transparent. In the method of the present invention, it is considered that certain factors causing coloring were removed by ozone.

[0274] Example 8: Preparation of carbamoyl chloride

[0275] [Chemical formula 12]

[0276]

[0277] A mixed gas of ozone:oxygen = 16:84 (volume ratio) was supplied to the photoreaction system schematically shown at a flow rate of 16.8 mL / min. In addition, chloroform containing pentene as a stabilizer was injected at a flow rate of 26.82 μL / min, vaporized with a heater, and mixed with the ozone-oxygen mixed gas to prepare an ozone-oxygen-chloroform mixed gas. Figure 3 The ozone-oxygen-chloroform mixed gas was continuously fed into a flow photoreactor and irradiated with light having a peak wavelength of 365 nm at 100 °C. In addition, dichloromethane (200 mL) was added to a two-necked flask, and while stirring at 0 °C, the gas obtained from the flow photoreactor was blown in for 1 hour.

[0278] The power supply of the LED lamp was turned off, the injection of chloroform was stopped, and the secondary amine or its hydrochloride (15 mmol) shown in Table 7 was injected into the above dichloromethane solution under a normal indoor lamp. Then, triethylamine (TEA) (60 mmol), which is 4 times the molar amount of the added amine, was added, and the mixture was stirred at 0 °C for 1 hour.

[0279] 1,2-Dichloroethane as an internal standard was added to the reaction solution, and analysis was carried out by

[0280] HNMR to confirm that the target compound carbamoyl chloride was produced at a yield of 75 - 97%. The results are shown in Table 7. It should be noted that the conversion efficiency in Table 7 is relative to the raw material secondary amine used. 1 Analysis was carried out by HNMR to confirm that the target compound carbamoyl chloride was produced at a yield of 75 - 97%. The results are shown in Table 7. It should be noted that the conversion efficiency in Table 7 is relative to the raw material secondary amine used.

[0281] [Table 7]

[0282]

[0283] In addition, for comparison, the same experiment was conducted using only oxygen instead of ozone. As a result, coloring was caused by TEA and the reaction solution turned brown.

[0284] In contrast, when ozone was used in addition to oxygen, no coloring occurred and the reaction solution containing the product was colorless and transparent. In the method of the present invention, it is considered that certain factors causing coloring were removed by ozone.

[0285] Example 9: Preparation of phenylalanine-N-carboxylic anhydride

[0286] [Chemical formula 13]

[0287]

[0288] A mixed gas of ozone:oxygen = 16:84 (volume ratio) was supplied to the Figure 3 schematically shown photoreaction system at a flow rate of 16.8 mL / min. In addition, chloroform containing pentene as a stabilizer was injected at a flow rate of 50.3 μL / min, vaporized with a heater, and mixed with the ozone-oxygen mixed gas to prepare a mixed gas of ozone-oxygen-chloroform.

[0289] The ozone-oxygen-chloroform mixed gas was continuously fed into a flow photoreaction apparatus and irradiated with light having a peak wavelength of 365 nm at 100°C. In addition, a solution obtained by suspending L-phenylalanine (6.6 g, 40 mmol) in a mixed solution of chloroform (60 mL, 740 mmol) and acetonitrile (60 mL, 1.1 mol) was added to a two-necked flask, and while stirring at 70°C, the gas obtained from the flow photoreaction apparatus was blown in for 2 hours.

[0290] Then, dichloromethane (2.56 mL, 40 mmol) was added to the reaction solution as an internal standard, and 1 analysis was performed by HNMR. As a result, the formation of the target compound phenylalanine-N-carboxylic anhydride could be confirmed (yield: >99%).

[0291] Example 10: Preparation of Vilsmeier reagent

[0292] [Chemical formula 14]

[0293]

[0294] A flow rate of 16.8 mL / min was used to feed into Figure 3A mixed gas of ozone:oxygen = 16:84 (volume ratio) is supplied to the schematically shown photoreaction system. Additionally, chloroform containing pentene as a stabilizer is injected at a flow rate of 50.3 μL / min, vaporized by a heater, and mixed with the ozone-oxygen mixed gas to prepare an ozone-oxygen-chloroform mixed gas.

[0295] The ozone-oxygen-chloroform mixed gas is continuously fed into a flow photoreaction device and irradiated with light having a peak wavelength of 365 nm at 100 °C. Additionally, a solution prepared by dissolving DMF (1.55 mL, 20 mmol) in chloroform (20 mL) is added to a two-necked flask, and while stirring at room temperature, the gas obtained from the flow photoreaction device is blown in for 1 hour. Then, the supply of the gas and the light irradiation are stopped, and the reaction solution is stirred at 50 °C for 1.5 hours. Subsequently, the stirring is stopped, and as a result, the reaction solution separates into two layers.

[0296] By 1 Analyzing each layer by 1H NMR, it was found that almost no peaks of the Vilsmeier reagent were observed in the lower layer. On the other hand, peaks of the Vilsmeier reagent (chloromethylene) dimethyliminium chloride were confirmed in the upper layer. Furthermore, the ratio of DMF remaining in the upper layer to the Vilsmeier reagent (DMF:Vilsmeier reagent) was approximately 1:6 based on the peak intensities, and it was estimated that up to 17 mmol of the Vilsmeier reagent was generated.

Claims

1. A method for preparing carbonyl halide, characterized in that, The method includes the step of irradiating a halogenated methane having one or more halogenated groups selected from chlorine, bromine, and iodine with light in the presence of oxygen and ozone.

2. The method according to claim 1, wherein Irradiate the mixed gas containing the halogenated methane, the oxygen, and the ozone with light.

3. The method according to claim 1, wherein, The proportion of the ozone relative to the total of the oxygen and the ozone is 1 vol% or more and 20 vol% or less.

4. The method according to claim 2, wherein, The volume ratio of the halogenated methane to the ozone is 0.1 times or more and 50 times or less.

5. The method according to claim 2, wherein The mixed gas does not contain chlorine.

6. The method according to claim 1, wherein, The time for irradiating the halogenated methane with the light is 60 seconds or more and 5000 seconds or less.

7. The method according to claim 1, wherein The temperature when irradiating the halogenated methane with the light is 50°C or more and 200°C or less.

8. A method for preparing a carbonate compound, characterized in that, The method includes: The step of preparing a carbonyl halide by the method according to any one of claims 1 - 7; and The step of reacting an alcohol compound with the carbonyl halide.

9. A method for preparing a haloformate compound, characterized in that, The method includes: The step of preparing a carbonyl halide by the method according to any one of claims 1 - 7; and The step of reacting an alcohol compound with the carbonyl halide.

10. A method for preparing an isocyanate compound, characterized in that, The method includes: The step of preparing a carbonyl halide by the method according to any one of claims 1 - 7; and The step of reacting a primary amine compound with the carbonyl halide.

11. A method for preparing a carbamyl halide compound, characterized in that, The method includes: The step of preparing a carbonyl halide by the method according to any one of claims 1 - 7; and The step of reacting a secondary amine compound with the carbonyl halide.

12. A method for preparing an amino acid-N-carboxylic anhydride, characterized in that, The amino acid - N - carboxylic anhydride is a substance represented by the following formula (VIII), and the method includes: The step of preparing a carbonyl halide by the method according to any one of claims 1 - 7; and The step of reacting an amino acid compound represented by the following formula (VII) with the carbonyl halide, [Chemical formula 1] In the formula, R 4 represents an amino acid side chain group in which the reactive group is protected, R 5 represents H or P 1 -[[-NH-CHR 6 -C(=O)-] l -, wherein R 6 represents an amino acid side chain in which the reactive group is protected, P 1 represents a protecting group for the amino group, l represents an integer of 1 or more, and when l is an integer of 2 or more, a plurality of R 6 may be the same as or different from each other.

13. A method for preparing a Vilsmeier reagent, characterized in that, The Vilsmeier reagent is a salt represented by the following formula (X), and the method includes: The step of preparing a carbonyl halide by the method according to any one of claims 1 - 7; and The step of reacting the carbonyl halide with an amide compound represented by the following formula (IX), [Chemical formula 2] In the formula, R 7 represents a hydrogen atom, C 1-6 alkyl group or a C 6-12 aromatic hydrocarbon group which may have substituents, R 8 and R 9 each independently represents C 1-6 alkyl or C aromatic hydrocarbon group which may have substituents, and further, R 6-12 and R 8 and R 9 may together form a ring structure having 4 or more and 7 or less members, X represents a halogenated group selected from chlorine, bromine, and iodine, Y - represents a counter anion, [Chemical formula 3] wherein, R 7 -R 9 has the same meaning as described above.

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