Method for producing carbonyl halide

Abstract

The present invention aims to provide a method for producing a carbonyl halide safely, at low cost, and with a low environmental impact. The method for producing a carbonyl halide according to the present invention is characterized by comprising a step of irradiating a mixed gas containing methane, a halogen elemental gas, and oxygen with light.

Description

[Technical Field]

[0001] The present invention relates to a method for producing carbonyl halides safely and at lower cost. [Background technology]

[0002] Carbonyl halides, such as carbonyl chloride, are very important as synthetic intermediates for various compounds. For example, carbonate derivatives are generally prepared from carbonyl chloride and compounds containing nucleophilic functional groups.

[0003] However, carbonyl chloride is highly toxic; it readily reacts with water to generate hydrogen chloride and has a history of use as a poisonous gas. Carbonyl chloride is primarily produced by the highly exothermic gas-phase reaction of anhydrous chlorine gas with high-purity carbon monoxide in the presence of an activated carbon catalyst (see, e.g., Patent Document 1). The carbon monoxide used here is also toxic. The basic production process for carbonyl chloride has not changed significantly since the 1920s. Producing carbonyl chloride using such a process requires expensive and large-scale facilities. However, due to the high toxicity of carbonyl chloride, extensive safety measures are essential in plant design, which increases production costs. Furthermore, large-scale carbonyl chloride production processes may cause numerous environmental problems. Alternatively, carbonyl chloride can be produced by decomposing triphosgene (bis(trichloromethyl)] carbonate) or diphosgene (trichloromethyl chloroformate) with a base such as triethylamine. However, triphosgene and diphosgene are expensive reagents, and are potentially dangerous as they can decompose into carbonyl chloride under some physical or chemical stimuli. They are also known to be highly toxic.

[0004] Therefore, the present inventors have developed a technique for generating halogen and / or carbonyl halide by irradiating halogenated hydrocarbon with light in the presence of oxygen (Patent Document 2). This technique is safe because the generated carbonyl halide can be reacted immediately by coexisting a reaction substrate compound such as an amine compound or an alcohol compound.

[0005] Furthermore, carbonyl halides not used in the reaction can be recovered by trapping to prevent leakage to the outside. For example, the present inventors have developed a technique for producing halogenated carboxylic acid esters by irradiating a mixture containing halogenated hydrocarbons and alcohols with light in the presence of oxygen (Patent Document 3). The present inventors have also developed a technique for producing carbonate derivatives by irradiating a composition containing halogenated hydrocarbons, a compound containing a nucleophilic functional group, and a base with light in the presence of oxygen (Patent Documents 4 and 5). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 9-59012 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-181028 [Patent Document 3] International Publication No. 2015 / 156245 Brochure [Patent Document 4] International Publication No. 2018 / 211952 Brochure [Patent Document 5] International Publication No. 2018 / 211953 Brochure Summary of the Invention [Problem to be solved by the invention]

[0007] As mentioned above, the present inventors have developed a technology for producing carbonyl halides by irradiating halogenated hydrocarbons with light in the presence of oxygen. It is possible to reuse halogenated hydrocarbons that have already been used. However, most of the halogenated hydrocarbons that can be reused have been used as solvents and are liquid at room temperature and pressure. Therefore, simple purification work and energy for gasification are required to react them in the gas phase. Furthermore, halogenated hydrocarbons are relatively expensive. Furthermore, although methane is inexpensive, its global warming potential as a greenhouse gas is approximately 25 times that of carbon dioxide, and therefore active consumption of methane is desirable. Therefore, an object of the present invention is to provide a method for producing a carbonyl halide safely, at low cost, and with a low environmental impact. [Means for solving the problem]

[0008] The present inventors have conducted extensive research to solve the above problems, and as a result have found that, while there is a risk of explosion when methane is reacted in the presence of oxygen, a carbonyl halide can be safely produced by irradiating a mixed gas containing methane, a halogen elemental gas, and oxygen with light, thereby completing the present invention. The present invention will now be described.

[0009] [1] A method for producing a carbonyl halide, comprising: A method comprising the step of irradiating a mixed gas containing methane, a halogen elemental gas, and oxygen with light. [2] The method according to [1], wherein the carbonyl halide is carbonyl chloride and the halogen element gas is chlorine gas. [3] The method according to [1] or [2], wherein the light has a peak wavelength of 360 nm or more and 830 nm or less. [4] The method according to any one of [1] to [3], wherein the mixed gas is irradiated with the light at room temperature. [5] The method according to any one of [1] to [4], wherein the shortest distance between a light source for irradiating the light and the mixed gas is 1 m or less. [6] The method according to any one of [1] to [5], further comprising a step of irradiating the mixed gas with light to neutralize hydrogen halide produced as a by-product with a basic sodium salt, thereby obtaining an aqueous sodium halide solution. [7] The method according to any one of [1] to [6], further comprising the step of obtaining a halogen element gas and sodium hydroxide by electrolysis of an aqueous sodium halide solution. [8] A method for producing a carbonate compound, comprising: a step of producing a carbonyl halide by the method according to any one of the above items [1] to [7]; and A method comprising the step of reacting an alcohol compound with the carbonyl halide. [9] A method for producing a halogenated formate compound, comprising: a step of producing a carbonyl halide by the method according to any one of the above items [1] to [7]; and A method comprising the step of reacting an alcohol compound with the carbonyl halide.

[10] A method for producing an isocyanate compound, comprising: a step of producing a carbonyl halide by the method according to any one of the above items [1] to [7]; and A method comprising the step of reacting a primary amine compound with the carbonyl halide.

[11] A method for producing a carbamoyl halide compound, comprising: a step of producing a carbonyl halide by the method according to any one of the above items [1] to [7]; and A method comprising the step of reacting a secondary amine compound with the carbonyl halide.

[12] A method for producing an amino acid-N-carboxylic acid anhydride, comprising: The amino acid-N-carboxylic acid anhydride is represented by the following formula (VIII): a step of producing a carbonyl halide by the method according to any one of the above items [1] to [7]; and A method comprising the step of reacting an amino acid compound represented by the following formula (VII) with the carbonyl halide:

[0010] [ka]

[0011] [In the formula, R 4 represents an amino acid side chain group in which a reactive group is protected, R 5 is H or P 1 -[-NH-CHR 6 -C(=O)-] l -(In the formula, R 6 indicates an amino acid side chain in which reactive groups are protected, and P 1 represents a protecting group for an 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 or different).

[13] A method for producing a Vilsmeier reagent, comprising: The Vilsmeier reagent is a salt represented by the following formula (X):

[0012] [ka]

[0013] [In the formula, R 7 is a hydrogen atom, C 1-6 alkyl group or optionally substituted C 6-12 represents an aromatic hydrocarbon group, R 8 and R 9 independently, C 1-6 alkyl group or optionally substituted C 6-12 represents an aromatic hydrocarbon group, and R 8 and R 9 may be joined together to form a 4- to 7-membered ring structure, X represents a halogeno group selected from the group consisting of chloro, bromo, and iodo; Y - indicates the counter anion.] a step of producing a carbonyl halide by the method according to any one of the above items [1] to [7]; and The method comprises a step of reacting the carbonyl halide with an amide compound represented by the following formula (IX):

[0014] [ka]

[0015] [In the formula, R 7 ~R 9 has the same meaning as above.]

[14] A method for producing a urea compound, comprising: a step of producing a carbonyl halide by the method according to any one of the above items [1] to [7]; and A method comprising the step of reacting a primary amine compound or a secondary amine compound with the carbonyl halide. [Effects of the Invention]

[0016] According to the method of the present invention, carbonyl halides can be produced at lower cost and with a lower environmental impact using methane, which is inexpensive and has a higher global warming potential than carbon dioxide, as a raw material. Furthermore, while reacting methane in the presence of oxygen poses a risk of explosion, irradiating a mixed gas containing methane, a halogen element, and oxygen with light likely results in a rapid reaction, safely producing carbonyl halides. Furthermore, the present invention also makes it possible to supply the produced carbonyl halide to a solution containing a reaction substrate compound in the same system and react therewith, or to introduce the reacted gas into a trap, thereby preventing or minimizing leakage of carbonyl halides from the system. Thus, the present invention is industrially useful for safely producing carbonyl halides, such as carbonyl chloride, at low cost and with a low environmental impact, and, by extension, for safely and efficiently producing compounds produced using carbonyl halides, such as carbonate derivatives, at low cost and with a low environmental impact. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of a reaction apparatus used in the present invention. [Figure 2] 1 shows the results of analyzing the reaction gas according to the present invention by 13C NMR. DETAILED DESCRIPTION OF THE INVENTION

[0018] The method of the present invention will be explained below step by step, but the present invention is not limited to the following specific examples.

[0019] ·Light irradiation process In this process, a mixed gas containing methane, a halogen element gas, and oxygen is irradiated with light to produce a carbonyl halide. Note that a carbonyl halide is also called a carbonyl dihalide, and for example, carbonyl chloride is also called carbonyl dichloride.

[0020] Since methane has a boiling point of -161.6°C and is a gas at room temperature and pressure, it is possible to use methane directly from a methane gas cylinder. Alternatively, it is possible to use methane gas with low environmental impact obtained by using methanogens to ferment organic matter such as food waste, paper waste, and livestock manure, or to use methane derived from methane hydrate. Furthermore, since most city gas is methane gas, it is possible to use city gas directly or methane gas purified from city gas. In addition, methods for producing methane from carbon dioxide and hydrogen have been developed, and methane gas synthesized by such methods may also be used.

[0021] Biogas may be used as a methane-containing raw material gas. Biogas is a gas generated by methane fermentation of waste from living organisms such as livestock, food waste, sludge derived from wastewater such as sewage, paper waste, vegetation waste, energy crops, etc., and is primarily composed of methane and carbon dioxide. For example, biogas contains 50 to 75 vol% methane and 25 to 50 vol% carbon dioxide, and may also contain nitrogen, hydrogen, hydrogen sulfide, oxygen, siloxane, etc. Biogas is obtained by methane fermentation of biological resources, and since carbon can be fixed by the present invention, it can be said to be carbon negative. Biogas generated by anaerobic fermentation of sewage sludge is called digester gas, and digester gas can also be used in the present invention.

[0022] City gas can also be used as a methane-containing feed gas. While city gas is primarily composed of methane, it is less expensive than purified methane and contains almost no or little components that interfere with the reaction in the present invention. For example, the composition of one city gas product was approximately 88.9 vol% methane, approximately 6.8 vol% ethane, approximately 3.1 vol% propane, and approximately 1.2 vol% butane.

[0023] The amount of methane used may be adjusted as appropriate within a range that allows a sufficient amount of carbonyl halide to be obtained, but for example, it may be used in an amount of 0.1 times or more by mole relative to the reaction substrate compound to be reacted with the generated carbonyl halide. There is no particular upper limit to the amount of methane used, but it may be, for example, 200 times or less by mole relative to the reaction substrate compound. The amount used is preferably 1 time or more by mole, 5 times or more by mole, or 10 times or more by mole, more preferably 20 times or more by mole, even more preferably 25 times or more by mole, and preferably 150 times or less by mole, more preferably 100 times or less by mole, and even more preferably 50 times or less by mole.

[0024] In the present invention, a gaseous elemental halogen is used. Examples of the elemental halogen include chlorine, bromine, and iodine. Since the boiling point of bromine is 58.8°C and iodine needs to be sublimated, chlorine and bromine are preferred, with chlorine being more preferred.

[0025] The halogen gas may be supplied from a commercially available halogenated gas cylinder, or may be prepared immediately. For example, chlorine can be produced by heating manganese(IV) oxide with concentrated hydrochloric acid, by adding concentrated hydrochloric acid to calcium hypochlorite, or industrially by electrolysis of a sodium chloride solution. MnO2+ 4HCl → MnCl2+ 2H2O + Cl2 Ca(ClO)2·3H2O + 4HCl → CaCl2+ 5H2O + 2Cl2 2NaCl + 2H2O → 2NaOH + H2+ Cl2

[0026] Bromine can be produced by adding KClO3 and H2SO4 to a Group 2 metal salt of bromide ion and heating the mixture, or by flowing a Group 2 metal salt of bromide ion down and introducing chlorine gas countercurrently from below. 3MgBr2+3H2SO4+KClO3→ 3MgSO4+KCl+3Br2+3H2O MgBr2+ Cl2 → MgCl2+ Br2

[0027] Iodine can be produced by using air to expel the easily vaporized iodine from brine containing iodide ions (blowout method), or by selectively adsorbing the iodide ions onto an ion exchange resin to concentrate them (ion exchange method).

[0028] The amount of halogen element gas used may be adjusted as appropriate within a range that allows a sufficient amount of carbonyl halide to be obtained, and may be, for example, 0.5 to 5 times by mole per mole of methane. The ratio is preferably 0.8 to 1 mole, more preferably 1 to 1 mole, and is preferably 3 to 2 moles.

[0029] The mechanism by which the reaction is promoted by the halogen element gas is not entirely clear, but it is possible that halogen oxides, which are produced by the photoreaction of halogen element gas with oxygen, react with methane. For example, chlorine oxides include chlorine monoxide, chlorine dioxide, and dichlorine heptaoxide.

[0030] The oxygen source may be any gas containing oxygen, such as air or purified oxygen. Purified oxygen may be mixed with an inert gas such as nitrogen or argon. Air can also be used from the standpoint of cost and ease. The use of air can further reduce the risk of explosion. For example, the oxygen content of the oxygen-containing gas can be adjusted to 15% by volume or more and 100% by volume or less. However, since reducing the oxygen content may potentially suppress excessive oxidation of methane, the oxygen content is preferably 75% by volume or less or 50% by volume or less, more preferably 30% by volume or less. Air is also preferred. The oxygen content of the oxygen-containing gas can be adjusted with an inert gas such as nitrogen, carbon dioxide, or argon. It is also preferred to use essentially only oxygen, excluding unavoidable impurities. The method for supplying the oxygen-containing gas is not particularly limited. It may be supplied to the reaction system from an oxygen cylinder equipped with a mass flow controller, or from an oxygen generator.

[0031] The amount of oxygen used may be adjusted as appropriate within a range that allows a sufficient amount of carbonyl halide to be obtained, and may be, for example, 0.1 to 5 times by mole relative to 1 mole of methane. The ratio is preferably 0.2 to 5 times by mole, more preferably 0.5 to 5 times by mole, and is preferably 4 to 2 times by mole, and more preferably 1.5 to 1 times by mole.

[0032] Ozone may be generated by irradiating oxygen with light, and this ozone may be involved in the reaction. Ozone may also be used in addition to oxygen.

[0033] A mixed gas containing methane, a halogen gas, and oxygen can be prepared in a batch or continuous manner by supplying each source gas to a photoreactor for irradiating light. Two or more source gases selected from methane, a halogen gas, and oxygen may be mixed in advance and then supplied to the photoreactor. For example, in the embodiment illustrated in FIG. 1, an oxygen-containing gas and chlorine gas are mixed in advance, and then methane gas is mixed to prepare a mixed gas.

[0034] The concentration of methane in the mixed gas may be adjusted as appropriate, and may be, for example, 5 vol% or more and 30 vol% or less. If the concentration is 5 vol% or more, it becomes possible to produce a carbonyl halide more efficiently, and if the concentration is 30 vol% or less, it is possible to more reliably suppress excessive decomposition of methane, and it becomes possible to produce a carbonyl halide with a higher yield. The concentration is preferably 10 vol% or more and 25 vol% or less.

[0035] Since carbonyl halide may react with water and decompose into carbon dioxide or hydrogen halide, if each source gas may contain moisture, it is preferable to dry it in advance. For example, it is preferable to dry a halogen elemental gas or air prepared just before use with a desiccant such as silica gel, calcium chloride, magnesium chloride, or calcium oxide.

[0036] When each source gas is continuously supplied, the ratio of the amount of each source gas used can be adjusted by the flow rate of each source gas supplied to the photoreactor. The flow rate of the mixed gas in the photoreactor for irradiating the mixed gas with light is preferably determined taking into account the internal volume of the photoreactor. For example, if the internal volume of the photoreactor is large, the residence time of the mixed gas tends to be long, so it is preferable to increase the flow rate. Conversely, if the internal volume is small, it is preferable to adjust the flow rate of the mixed gas to be slow. Specifically, since the internal volume of the photoreactor (L) / the flow rate of the mixed gas (L / sec) corresponds to the residence time (seconds) of the mixed gas in the photoreactor, the flow rate of the mixed gas can be determined from the desired residence time and the internal volume of the photoreactor. Furthermore, the linear velocity of the mixed gas in the photoreactor can be adjusted to approximately 0.001 m / min or more and 100 m / min or less. A linear velocity of 0.001 m / min or higher can more reliably suppress the photodecomposition of the generated carbonyl halide, while a linear velocity of 100 m / min or lower can more reliably ensure sufficient time for the conversion of methane, the halogen element gas, and oxygen to the carbonyl halide. The linear velocity can be calculated by dividing the velocity of the mixed gas passing through the photoreactor by the cross-sectional area of the photoreactor. If the cross-sectional area of the photoreactor is not constant, the cross-sectional area can be considered as the average cross-sectional area of the photoreactor in the direction of movement of the mixed gas. The average can be determined by dividing the volume of the photoreactor by the length of the mixed gas in the direction of movement within the photoreactor. The linear velocity is preferably 0.01 m / min or higher, and is preferably 50 m / min or lower or 20 m / min or lower, more preferably 10 m / min or lower or 5 m / min or lower, and even more preferably 1 m / min or lower or 0.5 m / min or lower.

[0037] The light irradiated onto the mixed gas can be high-energy light including short-wavelength light, such as light containing ultraviolet light. High-energy light including short-wavelength light may efficiently generate carbonyl halides. Specifically, light including wavelengths of 180 nm to 500 nm and light with a peak wavelength of 180 nm to 500 nm can be used. The peak wavelength here refers to the wavelength of light with the highest intensity. The wavelength of the irradiated light can be determined appropriately, but light with a wavelength of 400 nm or less, light with a wavelength of 300 nm or less, and light with a peak wavelength within these ranges can also be used. For example, light including UV-B with a wavelength of 280 nm to 315 nm and / or UV-C with a wavelength of 180 nm to 280 nm can be used, and light including UV-C with a wavelength of 180 nm to 280 nm can also be used, and light with a peak wavelength within these ranges can also be used.

[0038] In the present invention, in order to suppress decomposition of the generated carbonyl halide, safe light with relatively low energy may be used. Examples of relatively low-energy irradiation light include light whose peak wavelength is within the visible light wavelength range.

[0039] Specifically, visible light refers to light having a peak wavelength of 360 nm or more and 830 nm or less. The spectral distribution of the irradiated light used in the method of the present invention may include high-energy light such as ultraviolet light, but as long as the peak wavelength of the spectral distribution is within this range, the influence of ultraviolet light is considered to be small. The peak wavelength refers to the wavelength of light with the highest intensity in the spectral distribution of light. The peak wavelength is preferably 400 nm or more, and is preferably 800 nm or less or 700 nm or less, and more preferably 600 nm or less. High-energy light such as ultraviolet light can be blocked by using a reaction vessel made of borosilicate glass such as Pyrex (registered trademark) glass.

[0040] Among the halogen elemental gases used in the present invention, chlorine gas is highly convenient because it is a gas at room temperature and normal pressure. Chlorine gas particularly absorbs light of 280 nm or more and less than 360 nm. Therefore, it is also preferable that the irradiated light contains light of 280 nm or more and less than 360 nm. As mentioned above, as long as the peak wavelength is in the range of 360 nm or more and 830 nm or less, it is considered safer even if it contains light of 280 nm or more and less than 360 nm.

[0041] The means for light irradiation is not particularly limited as long as it can irradiate light of the above wavelength, and examples of light sources that include light in this wavelength range include sunlight, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, chemical lamps, black light lamps, metal halide lamps, LED lamps, etc. From the standpoints of reaction efficiency and cost, low-pressure mercury lamps and LED lamps are preferred, and LED lamps are more preferred.

[0042] The conditions such as the intensity and irradiation time of the irradiated light may be appropriately set depending on the type and amount of the starting material. For example, the light intensity at the shortest distance from the light source to the mixed gas is 1 mW / cm. 2 More than 100mW / cm 2 The light irradiation time is preferably 1 minute or more and 10 hours or less, more preferably 5 minutes or more and 5 hours or less, and even more preferably 10 minutes or more and 1 hour or less. The light irradiation mode is not particularly limited, and any mode can be used, such as continuous light irradiation from the start to the end of the reaction, alternating light irradiation and non-light irradiation, or light irradiation for only a predetermined time from the start of the reaction. However, a mode in which light is continuously irradiated from the time the reaction gas is supplied to the photoreactor until it is discharged is preferred. Furthermore, the shortest distance between the light source and the mixed gas is preferably 1 m or less, more preferably 50 cm or less, and even more preferably 10 cm or less or 5 cm or less. The lower limit of this shortest distance is not particularly limited, but may be 0 cm, i.e., the light source may be installed in the photoreactor or the mixed gas. When light is irradiated from the side of the reaction vessel, the shortest distance can be 1 cm or more or 2 cm or more.

[0043] The temperature during the photoreaction is not particularly limited and may be adjusted as appropriate, but can be, for example, −20° C. or higher and 200° C. or lower. The temperature is more preferably −10° C. or higher, even more preferably 0° C. or higher or 10° C. or higher, more preferably 150° C. or lower or 100° C. or lower, and even more preferably 60° C. or lower or 35° C. or lower. Alternatively, the reaction may be carried out at room temperature without temperature control.

[0044] Irradiating the mixed gas with light is thought to produce a carbonyl halide [XC(=O)-X (X is one or more halogeno groups selected from the group consisting of chloro, bromo, and iodo)]. Furthermore, when a reaction substrate compound is present in the reaction system, it is thought that not only the produced carbonyl halide but also a carbonyl halide-like compound that functions similarly to a carbonyl halide will react with the reaction substrate compound. The carbonyl halide according to the present invention also includes such carbonyl halide-like compounds. Representative examples of reactions using carbonyl halide will be described below.

[0045] Reaction apparatuses that can be used in the method of the present invention include those equipped with a light irradiation means in a reaction vessel. Figure 1 shows one embodiment of a reaction apparatus that can be used in the production method of the present invention. In the reaction apparatus shown in Figure 1, a halogen element gas is generated in a halogen element gas generator 3, while an oxygen-containing gas dried in a silica gel drying tube 1 is supplied to the halogen element gas generator 3 to obtain a mixed gas of the halogen element gas and the oxygen-containing gas. The resulting mixed gas is dried in a calcium chloride drying tube 4 and then mixed with methane gas to obtain a mixed gas. The mixed gas may be heated using a coil heater 6. The flow rate of the mixed gas can be adjusted using a mass flow controller 2. The mixed gas is supplied to a photoreactor 7 and irradiated with light from a light source 9. The temperature of the photoreaction in the photoreactor 7 can be adjusted using a heater 8. The reaction gas discharged from the photoreactor 7 contains a carbonyl halide. The reaction substrate compound and the carbonyl halide can be reacted by blowing the reaction gas into a solution containing the reaction substrate compound in a reaction vessel 10. The exhaust gas that has passed through the reaction vessel 10 may be supplied to a trap for capturing and / or decomposing excess carbonyl halide. With such a reaction apparatus, the production and consumption of carbonyl halide and the production of useful compounds can be carried out within the same system, and leakage of carbonyl halide outside the system can be suppressed.

[0046] ·Neutralization process In this step, hydrogen halide, which is a by-product of irradiating the mixed gas with light, is neutralized with a basic sodium salt to obtain an aqueous sodium halide solution.

[0047] In the method of the present invention, hydrogen halide is produced from methane presumably according to the following reaction formula: CH4+ 3X2+ 1 / 2O2→ XC(=O)-X + 4HX Furthermore, when the obtained carbonyl halide is used in a reaction, hydrogen halide can be produced. The by-produced hydrogen halide may be purified or partially purified to produce a product hydrogen halide or an aqueous solution thereof. Meanwhile, in this step, the hydrogen halide by-produced in the process of the present invention or the hydrogen halide by-produced by the reaction of the carbonyl halide obtained by the process of the present invention is neutralized to prepare an aqueous sodium halide solution. The aqueous sodium halide solution obtained in this step can be used, for example, as all or part of the aqueous sodium halide solution used in the process for producing a halogen elemental gas described below, thereby further improving the efficiency of the process of the present invention.

[0048] The basic sodium salt refers to a sodium ion salt whose aqueous solution exhibits basicity. Examples of basic sodium salts include sodium hydroxide, sodium bicarbonate, sodium carbonate, sodium acetate, disodium hydrogen phosphate, and sodium citrate, and basic sodium salts selected from sodium hydroxide, sodium bicarbonate, and sodium carbonate are preferred.

[0049] The conditions for carrying out this step may be appropriately selected. For example, the aqueous solution of a basic sodium salt may be neutralized by introducing hydrogen halide by-produced in the process of the present invention or hydrogen halide by-produced by the reaction of carbonyl halide obtained by the process of the present invention into the aqueous solution of the basic sodium salt. Furthermore, sodium halide and water are produced by the reaction of the basic sodium salt with hydrogen halide, and this aqueous sodium halide solution can be used in the process for producing a halogen elemental gas described below.

[0050] -Halogen element gas manufacturing process In this process, a halogen element gas, which is one of the raw material gases for the light irradiation process, is produced by electrolysis of a sodium halide aqueous solution. While this process is optional and, for example, a purchased halogen element gas product may be used, this process makes it possible to produce relatively dangerous halogen element gas, which exhibits toxicity and corrosiveness, in situ, thereby reducing the possibility of accidents due to transportation of the halogen element gas. Furthermore, when chlorine gas is used as the halogen element gas, the cost of carrying out this process can be significantly reduced by using seawater as the sodium chloride aqueous solution.

[0051] The electrolysis of the sodium halide aqueous solution may be carried out by a conventional method. For example, titanium, platinum, or the like can be used as the electrode metal. Direct current can be used as the current. During the electrolysis of the sodium halide aqueous solution, a halogen element is generated at the anode, and sodium hydroxide is generated at the cathode. Since sodium hypohalite (NaOX) may be generated by the reaction of the halogen element with sodium hydroxide, the sodium halide aqueous solution may be irradiated with ultrasound during electrolysis, or the two electrodes may be separated by a diaphragm.

[0052] The aqueous sodium halide solution may be a commercially available aqueous sodium halide solution or may be prepared by dissolving commercially available sodium halide in water. However, by utilizing the basic sodium salt obtained in the neutralization step, it is possible to further improve the efficiency of the method of the present invention.

[0053] Hereinafter, examples of reactions between the carbonyl halide produced by the method of the present invention and a reaction substrate compound will be described.

[0054] Post-reaction process - carbonate compound production A carbonate compound can be produced by reacting a carbonyl halide with an alcohol compound. The reaction mode is not particularly limited, and for example, as shown in Figure 1, a gas containing the produced carbonyl halide may be blown into a composition containing an alcohol compound in a reaction vessel 10.

[0055] An alcohol compound is an organic compound having a hydroxyl group, and examples thereof include a monohydric alcohol compound represented by the following formula (I) and a dihydric alcohol compound represented by the following formula (II). Hereinafter, a compound represented by formula x may be abbreviated as "compound x." For example, a "monohydric alcohol compound represented by formula (I)" may be abbreviated as "monohydric alcohol compound (I)." R 1 -OH (I) HO-R 2 -OH (II) [In the formula, R 1 represents a monovalent organic group, and R 2 represents a divalent organic group.]

[0056] The organic group is not particularly limited as long as it is inert to the reaction in this step. For example, C 1-10 Aliphatic hydrocarbon group, optionally substituted C 6-30 Aromatic hydrocarbon groups, optionally substituted heteroaryl groups, and optionally substituted C groups having 2 or more and 5 or less C groups. 1-10 C optionally having an aliphatic hydrocarbon group and a substituent 6-12 An organic group to which an aromatic hydrocarbon group is bonded, and a C 1-10 Examples include organic groups to which an aliphatic hydrocarbon group and an optionally substituted heteroaryl group are bonded.

[0057] C 1-10 Examples of the aliphatic hydrocarbon group include C 1-10 Acyclic aliphatic hydrocarbon group, C 3-10 Cyclic aliphatic hydrocarbon groups and C groups of 2 or more and 5 or less 1-10 Acyclic aliphatic hydrocarbon groups and C 3-10 Examples include organic groups to which cyclic aliphatic hydrocarbon groups are bonded.

[0058] "C 1-10The term "linear aliphatic hydrocarbon group" refers to a linear or branched saturated or unsaturated aliphatic hydrocarbon group having 1 to 10 carbon atoms. For example, a monovalent C 1-10 As the chain aliphatic hydrocarbon group, C 1-10 Alkyl group, C 2-10 Alkenyl groups, and C 2-10 Mention may be made of alkynyl groups.

[0059] C 1-10 Examples of the alkyl group 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, and n-decyl. 1-6 alkyl group, more preferably C 1-4 It is preferably an alkyl group, and even more preferably methyl.

[0060] C 2-10 Examples of alkenyl groups include ethenyl (vinyl), 1-propenyl, 2-propenyl (allyl), butenyl, hexenyl, octenyl, and decenyl. 2-8 alkenyl group, more preferably C 4-6 It is an alkenyl group.

[0061] C 2-10 Examples of the alkynyl group include ethynyl, propynyl, butynyl, hexynyl, octynyl, and pentadecynyl. 2-8 Alkynyl groups, more preferably C 2-6 It is an alkynyl group.

[0062] "C 3-10 The term "alicyclic hydrocarbon group" refers to a cyclic saturated or unsaturated aliphatic hydrocarbon group having 3 to 10 carbon atoms. For example, a monovalent C 3-10 The cyclic aliphatic hydrocarbon group is C 3-10 Cycloalkyl groups, C 4-10 Cycloalkenyl groups, and C 4-10Mention may be made of cycloalkynyl groups.

[0063] C: 2 or more, 5 or less 1-10 Acyclic aliphatic hydrocarbon groups and C 3-10 Examples of the organic group to which a cyclic aliphatic hydrocarbon group is bonded include C 3-10 Monovalent cycloaliphatic hydrocarbon group -C 1-10 Divalent chain aliphatic hydrocarbon groups and C 1-10 Monovalent aliphatic hydrocarbon group -C 3-10 Divalent cycloaliphatic hydrocarbon group -C 1-10 Examples include divalent chain aliphatic hydrocarbon groups.

[0064] "C 6-12 The term "aromatic hydrocarbon group" refers to an aromatic hydrocarbon group having 6 to 12 carbon atoms. For example, a monovalent C 6-12 The aromatic hydrocarbon group is phenyl, indenyl, naphthyl, biphenyl, etc., and preferably phenyl.

[0065] "C 6-30 The term "aromatic hydrocarbon group" refers to an aromatic hydrocarbon group having 6 to 30 carbon atoms. For example, a divalent C 6-30 Examples of aromatic hydrocarbon groups include divalent C groups such as phenylene, indenylene, naphthylene, and biphenylene. 6-12 In addition to the aromatic hydrocarbon group, examples thereof include the aromatic hydrocarbon group contained in the alcohol compound (II-1) described below.

[0066] The term "heteroaryl group" refers to a 5-membered aromatic heterocyclyl group, 6-membered aromatic heterocyclyl group, or fused-ring aromatic heterocyclyl group having at least one heteroatom such as a nitrogen atom, oxygen atom, or sulfur atom. Examples include monovalent 5-membered heteroaryl groups such as pyrrolyl, imidazolyl, pyrazolyl, thienyl, furyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, and thiadiazole; monovalent 6-membered heteroaryl groups such as pyridinyl, pyrazinyl, pyrimidinyl, and pyridazinyl; and monovalent fused-ring aromatic heterocyclyl groups such as indolyl, isoindolyl, quinolinyl, isoquinolinyl, benzofuranyl, isobenzofuranyl, and chromenyl.

[0067] "2 or more, 5 or less, C 1-10 Aliphatic hydrocarbon groups and C 6-12 Examples of the "organic group having an aromatic hydrocarbon group bonded thereto" include C 6-12 Aromatic hydrocarbon group -C 1-10 Acyclic aliphatic hydrocarbon group, C 1-10 Chain aliphatic hydrocarbon group -C 6-12 Aromatic hydrocarbon group, C 1-10 Chain aliphatic hydrocarbon group -C 6-12 Aromatic hydrocarbon group -C 1-10 Chain aliphatic hydrocarbon groups, and C 6-12 Aromatic hydrocarbon group -C 1-10 Chain aliphatic hydrocarbon group -C 6-12 Aromatic hydrocarbon groups include those having 2 or more and 5 or less C 1-10 Examples of the "organic group to which an aliphatic hydrocarbon group and a heteroaryl group are bonded" include the heteroaryl group -C 1-10 Acyclic aliphatic hydrocarbon group, C 1-10 Chain aliphatic hydrocarbon group-heteroaryl group, C 1-10 Chain aliphatic hydrocarbon group-heteroaryl group-C 1-10 Chain aliphatic hydrocarbon groups and heteroaryl groups -C 1-10 Examples include a chain aliphatic hydrocarbon group-heteroaryl group.

[0068] C 1-10 Examples of the substituents that the aliphatic hydrocarbon group may have include one or more substituents selected from the group consisting of a halogeno group, a nitro group, and a cyano group, with a halogeno group being preferred. 6-12 Examples of the substituents that the aromatic hydrocarbon group and heteroaryl group may have include C 1-6 Alkyl group, C 1-6 The substituents may be one or more selected from the group consisting of alkoxy, halogeno, nitro, and cyano groups, with halogeno being preferred. The "halogeno group" includes fluoro, chloro, bromo, and iodo, with fluoro being preferred.

[0069] Furthermore, alcohol compounds can also be divided into fluorinated alcohol compounds that essentially have a fluoro group as a substituent, and non-fluorinated alcohols that are not substituted with a fluoro group. The halogeno group that the non-fluorinated alcohol may have as a substituent is one or more halogeno groups selected from chloro, bromo, and iodo. In addition, the group "R" having a fluoro group as a substituent x " is "R F x " can also be written as ".

[0070] "C 1-6 The term "alkyl group" refers to a linear or branched monovalent saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms. Examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, and n-hexyl. Preferably, C 1-4 alkyl group, more preferably C 1-2 It is preferably an alkyl group, and even more preferably methyl.

[0071] "C 1-6 The term "alkoxy group" refers to a linear or branched saturated aliphatic hydrocarbon oxy group having 1 to 6 carbon atoms. Examples include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, t-butoxy, n-pentoxy, n-hexoxy, etc., and preferably C 1-4 is an alkoxy group, more preferably C 1-2 It is an alkoxy group, and even more preferably methoxy.

[0072] The monohydric alcohol compound (I) may be a monohydric 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.

[0073] The divalent organic group may be a divalent organic group corresponding to the examples of the monovalent organic group. For example, the monovalent organic group C 1-10 Alkyl group, C 2-10 Alkenyl groups, and C 2-10 The divalent organic group corresponding to the alkynyl group is C 1-10 Alkanediyl, C 2-10 Alkenediyl group, and C 2-10 It is an alkynediyl group.

[0074] The divalent organic group is a divalent (poly)alkylene glycol group -[-OR 2 -] n -[wherein, R 2 is C 1-8 represents an alkanediyl group, and n represents an integer of 1 or more and 50 or less.

[0075] Furthermore, examples of the dihydric alcohol compound (II) include the following dihydric alcohol compound (II-1).

[0076] [ka]

[0077] [In the formula, R 11 and R 12 are independently H, C 1-6 Alkyl group, C 1-6 Fluoroalkyl group or C 6-12 Indicates an aromatic hydrocarbon group or together with C 1-6 C optionally substituted with alkyl 3-6 forming a cycloalkyl, R 13 and R 14 are independently H, C 1-6 Alkyl group or C 6-12 represents an aromatic hydrocarbon group, and when p1 or p2 is an integer of 2 or more, a plurality of R 13 or R 14 may be the same or different from each other, p1 and p2 independently represent an integer of 0 or more and 4 or less.

[0078] Specific examples of the dihydric non-fluorinated alcohol compound (II-1) include 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, and 2,2-bis(4-hydroxy-3-isopropylphenyl)propane, with 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) being preferred.

[0079] The dihydric alcohol compound (II) may be a dihydric fluorinated alcohol compound. Examples of the dihydric fluorinated alcohol compound (II) include fluorinated ethylene glycol, fluorinated propylene glycols such as monofluoropropylene glycol and difluoropropylene glycol, fluorinated butanediols such as monofluorobutanediol, difluorobutanediol, trifluorobutanediol, and tetrafluorobutanediol, fluorinated pentanediols such as monofluoropentanediol, difluoropentanediol, trifluoropentanediol, tetrafluoropentanediol, pentafluoropentanediol, and hexafluoropentanediol, and fluorinated pentanediols such as monofluorohexanediol, difluorohexanediol, trifluorohexanediol, tetrafluorohexanediol, pentafluorohexanediol, hexafluorohexanediol, heptafluorohexanediol, and octafluorohexanediol. fluorinated hexanediols such as hexanediol; fluorinated heptanediols such as monofluoroheptanediol, difluoroheptanediol, trifluoroheptanediol, tetrafluoroheptanediol, pentafluoroheptanediol, hexafluoroheptanediol, heptafluoroheptanediol, octafluoroheptanediol, nonafluoroheptanediol, and decafluoroheptanediol; fluorinated octanediols such as monofluorooctanediol, difluorooctanediol, trifluorooctanediol, tetrafluorooctanediol, pentafluorooctanediol, hexafluorooctanediol, heptafluorooctanediol, octafluorooctanediol, nonafluorooctanediol, decafluorooctanediol, undecafluorooctanediol, and dodecafluorooctanediol;Fluorinated nonanediols such as monofluorononanediol, difluorononanediol, trifluorononanediol, tetrafluorononanediol, pentafluorononanediol, hexafluorononanediol, heptafluorononanediol, octafluorononanediol, nonafluorononanediol, decafluorononanediol, undecafluorononanediol, dodecafluorononanediol, tridecafluorononanediol, and tetradecafluorononanediol; monofluorodecanediol, difluorodecanediol, trifluorodecanediol, tetrafluorodecanediol, and pentafluorodecanediol Fluorinated decanediols such as hexafluorodecanediol, heptafluorodecanediol, octafluorodecanediol, nonafluorodecanediol, decafluorodecanediol, undecafluorodecanediol, dodecafluorodecanediol, tridecafluorodecanediol, tetradecafluorodecanediol, pentadecafluorodecanediol, and hexadecafluorodecanediol; fluorinated polyethylene glycols such as fluorinated diethylene glycol, fluorinated triethylene glycol, fluorinated tetraethylene glycol, fluorinated pentaethylene glycol, and fluorinated hexaethylene glycol;

[0080] The amount of alcohol compound used may be adjusted as appropriate within a range in which the reaction proceeds smoothly. For example, a dihydric alcohol compound having a molar ratio of 1 or more relative to the carbonyl halide produced can be used, and a monohydric alcohol compound having a molar ratio of 2 or more can be used. By using an excess of alcohol compound, a carbonate compound can be obtained more efficiently. However, since the yield of carbonyl halide relative to the methane used is not constant, it is preferable that the molar ratio of dihydric alcohol compound to methane is 1 or more, and the molar ratio of monohydric alcohol compound to methane is 2 or more. The molar ratio of dihydric alcohol is preferably 1.5 or more, more preferably 2 or more, and is preferably 10 or less, and preferably 5 or less. The molar ratio of monohydric alcohol is preferably 2.5 or more, more preferably 4 or more, and is preferably 20 or less, and preferably 10 or less.

[0081] A base may be used to promote the reaction between the carbonyl halide and the alcohol compound. Bases are classified into inorganic and organic bases. Examples of inorganic bases include alkali metal carbonates such as lithium carbonate, sodium carbonate, potassium carbonate, and cesium carbonate; Group 2 metal carbonates such as magnesium carbonate, calcium carbonate, and barium carbonate; alkali metal bicarbonates such as lithium bicarbonate, sodium bicarbonate, potassium bicarbonate, and cesium bicarbonate; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; Group 2 metal hydroxides such as magnesium hydroxide and calcium hydroxide; and alkali metal fluoride salts such as lithium fluoride, sodium fluoride, potassium fluoride, and cesium fluoride. Carbonates or bicarbonates of alkali metals or Group 2 metals, which have relatively low hygroscopicity and deliquescence, are preferred, and alkali metal carbonates are more preferred. Examples of organic bases include tri(C) bases such as trimethylamine, triethylamine, and diisopropylethylamine, from the viewpoint of low reactivity with the product of the photoreaction of tetrahaloethylene. 1-4Alkyl)amines; alkali metal tert-butoxides 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, as well as weakly nucleophilic organic bases such as pyridine and lutidine.

[0082] During photoreactions or reactions between carbonyl halides and alcohol compounds, hydrogen halides such as hydrogen chloride are produced as by-products. Bases are effective in capturing such hydrogen halides, but when small-diameter piping is used, a salt of the hydrogen halide and the base may precipitate, causing clogging. In such cases, it is preferable to use a base whose salt of the hydrogen halide and the base forms an ionic liquid. Examples of such bases include organic bases such as imidazole derivatives such as 1-methylimidazole. Bases such as pyridine, whose hydrochloride salts have a relatively low melting point, can also be used.

[0083] The amount of base used may be adjusted as appropriate within the range in which the reaction proceeds well, and may be, for example, 1 mol or more and 10 mol or less per mol of methane.

[0084] The base may be added to the alcohol compound in advance, or may be continuously injected together with the alcohol compound.

[0085] When reacting a carbonyl halide with an alcohol compound, a solvent may be used. The solvent may be added to a composition containing an alcohol compound. Examples of the solvent 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; nitrile solvents such as acetonitrile; and halogenated hydrocarbon solvents such as dichloromethane and chloroform.

[0086] The temperature for reacting the carbonyl halide with the alcohol compound is not particularly limited and may be adjusted as appropriate, for example, to a temperature of 0° C. or higher and 250° C. or lower. The temperature is more preferably 10° C. or higher, even more preferably 20° C. or higher, more preferably 200° C. or lower or 150° C. or lower, and even more preferably 100° C. or lower or 80° C. or lower. However, when no base is used or when a base is used and it is desired to further promote the reaction, the temperature may be adjusted to a relatively high temperature, such as 50° C. or higher or 100° C. or higher.

[0087] The time for reacting the carbonyl halide with the alcohol compound is not particularly limited and may be adjusted as appropriate, but is preferably, for example, 0.5 hours or more and 50 hours or less. The reaction time is more preferably 1 hour or more, even more preferably 5 hours or more, and more preferably 30 hours or less, and even more preferably 20 hours or less. Furthermore, even after the production of the carbonyl halide is complete, stirring of the reaction solution may be continued, for example, until consumption of the alcohol compound is confirmed.

[0088] When a monohydric alcohol compound (I) is used, the reaction between a carbonyl halide and an alcohol compound produces a chain carbonate compound represented by the following formula (III), while 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 mainly produced. When a dihydric alcohol compound (II) is used, whether a polycarbonate compound (IV-1) or a cyclic carbonate compound (IV-2) is produced, and the ratio of their production, mainly depends on the distance between the two hydroxyl groups in the dihydric alcohol compound (II) and the flexibility of the chemical structure. Specific confirmation can be achieved by preliminary experiments, etc. R 1 -OC(=O)-OR 1 (III) [-OR 2 -OC(=O)-] (IV-1)

[0089] [ka]

[0090] According to the present invention, the polymerization reaction proceeds very efficiently, and it is possible to obtain a polycarbonate compound having a high molecular weight. For example, the polycarbonate compound obtained by the method of the present invention preferably has a weight average molecular weight, calculated on a polystyrene basis, of 10,000 to 1,000,000, and a number average molecular weight, calculated on a polystyrene basis, of 5,000 to 500,000, as analyzed by gel permeation chromatography (GPC).

[0091] Post-reaction process - Production of halogenated formates In the above-mentioned method for producing a carbonate compound, a base is not used and the amount of the alcohol compound used is adjusted to a relatively low level, for example, the molar ratio of the alcohol compound to methane is set to less than 1, thereby mainly producing a halogenated formate ester. The molar ratio is preferably 0.9 or less, more preferably 0.8 or less. Depending on the conditions, both a carbonate compound and a halogenated formate ester can be obtained. The monohydric alcohol compound (I) can be used as the alcohol compound. Furthermore, a halogenated formate fluoride can be obtained from the monohydric fluorinated alcohol compound (I), and a halogenated formate non-fluorinated can be obtained from the monohydric non-fluorinated alcohol compound (I).

[0092] Post-reaction process - production of isocyanate compounds An isocyanate compound can be produced by reacting a carbonyl halide with a primary amine compound. The isocyanate compound is useful as a raw material for carbamate compounds, urethane compounds, etc. As a reaction mode, a primary amine compound may be used instead of an alcohol compound in the above-mentioned method for producing a carbonate compound, except for the following points.

[0093] The primary amine compound is not particularly limited as long as it is a compound having one or more primary amino groups (—NH groups). For example, the primary amine compound (V):R 3 -(NH2) m can be used. 3 represents an m-valent organic group, where 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 even more preferably 2.

[0094] organic group R 3 Among these, the monovalent organic group is the monovalent organic group R 1 The divalent organic group can be a divalent organic group R 2 The trivalent or higher organic group may be a monovalent organic group R 1Examples of the trivalent or higher organic groups include monovalent organic groups such as C 1-10 Alkyl group, C 2-10 Alkenyl groups, and C 2-10 The trivalent organic group corresponding to the alkynyl group is C 1-10 Alcantriyl, C 2-10 Alkentriyl group, and C 2-10 It is an alkynetriyl group.

[0095] The reaction of carbonyl halide with primary amine compound (V) produces isocyanate compound (VI):R 3 -(N=C=O) m However, the generated R 3 -(N=C=O) m reacts with a primary amine compound (V) to form a urea compound R 3 -[NH-C(=O)-NH-R 3 ] m In order to suppress such a reaction, it is preferable to adjust the amount of the primary amine compound (V) used to a relatively low level, for example, to adjust the molar ratio of the primary amine compound (V) to methane to 1 or less, or to use a salt as the primary amine compound (V), or to not use a base. Alternatively, the generated carbonyl halide may be dissolved in a solvent to prepare a carbonyl halide solution, and the primary amine compound (V) or a solution thereof may be added to the solution while maintaining the molar ratio of the carbonyl halide to the primary amine compound (V) at a level greater than 1, thereby enabling efficient production of an isocyanate compound.

[0096] When the target compound is an isocyanate compound, it is preferable to set the molar ratio of the primary amine compound (V) to the carbonyl halide produced to 1 or less, but since it is sometimes difficult to predict the exact amount of carbonyl halide produced, it is preferable to set the molar ratio of the primary amine compound (V) to the methane used to less than 1. The molar ratio is preferably 0.5 or less, more preferably 0.2 or less, and is preferably 0.001 or more, more preferably 0.05 or more.

[0097] When the target compound is an isocyanate compound, it is preferable to use a salt as the primary amine compound (V) because isocyanate compounds are unlikely to react with amine salts. Examples of such salts include inorganic acid salts such as hydrochloride, hydrobromide, hydroiodide, sulfate, nitrate, perchlorate, and phosphate; and organic acid salts such as oxalate, malonate, maleate, fumarate, lactate, malate, citrate, tartrate, benzoate, trifluoroacetate, acetate, methanesulfonate, p-toluenesulfonate, and trifluoromethanesulfonate.

[0098] The temperature for the reaction of the carbonyl halide with the primary amine compound is preferably set lower than the reaction temperature with the alcohol compound, for example, in order to maintain the carbonyl halide in a liquid state. For example, the reaction temperature can be set to 15°C or lower, preferably 10°C or lower, more preferably 5°C or lower, and even more preferably 2°C or lower. There is no particular lower limit to the temperature, but for example, the temperature is preferably -80°C or higher, more preferably -20°C or higher or -15°C or higher.

[0099] When the target compound is an isocyanate compound and a base is used, the base is preferably one or more bases selected from heterocyclic aromatic amines and non-nucleophilic strong bases. Heterocyclic aromatic amines refer to compounds containing at least one heterocycle and at least one amine functional group other than -NH. Examples of heterocyclic aromatic amines include pyridine and its derivatives, such as pyridine, α-picoline, β-picoline, γ-picoline, 2,3-lutidine, 2,4-lutidine, 2,6-lutidine, 3,5-lutidine, 2-chloropyridine, 3-chloropyridine, 4-chloropyridine, 2,4,6-trimethylpyridine, and 4-dimethylaminopyridine.

[0100] The term "strong non-nucleophilic base" refers to a base that has a weak nucleophilicity of the lone electron pair on the nitrogen atom due to steric hindrance, but is a strong base. Examples include triethylamine, N,N-diisopropylethylamine, tripropylamine, triisopropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, tridecylamine, tridodecylamine, 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). Alternatively, a base with a relatively high basicity may be used. For example, the basicity (pK BH+ ) as 20 or more bases, 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.

[0101] Other bases that can be used include general-purpose organic amines such as trimethylamine, dimethylethylamine, diethylmethylamine, N-ethyl-N-methylbutylamine, and 1-methylpyrrolidine.

[0102] Post-reaction process - Production of carbamoyl halide compounds A carbamoyl halide compound can be produced by reacting a carbonyl halide with a secondary amine compound. Carbamoyl halide compounds are useful as synthetic intermediates for carbamate esters, such as carbamate compounds with insecticidal properties, and physiologically active substances such as pharmaceuticals and pesticides. Furthermore, carbamoyl halide compounds having two or more carbamoyl halide groups [—N(C═O)—Cl] can be used as raw materials for polyurea and polyurethane. In a reaction mode, a secondary amine compound may be used instead of a primary amine compound in the above-mentioned method for producing an isocyanate compound.

[0103] The secondary amine compound is not particularly limited as long as it is a compound having one or more secondary amino groups (—NHR groups). For example, the secondary amine compound (XI):R 21 -(NH-R 22 ) m can be used. 21 represents an m-valent organic group, where m is an integer of 1 to 6, preferably 5 or less, 4 or less, or 3 or less, more preferably 1 or 2, and even more preferably 2. 22 represents a monovalent organic group, and the monovalent organic group R 1 and C 1-10 Alkyl groups are preferred.

[0104] The reaction of a carbonyl halide with a secondary amine compound (XI) gives a carbamoyl halide compound (XII):R 21 -[N(R 22 )-C(=O)-X] m (wherein X represents one or more halogeno groups selected from the group consisting of chloro, bromo, and iodo) is obtained. However, the produced R 21 -[N(R 22 )-C(=O)-X] mand the secondary amine compound (XI), which may react to produce a urea compound. To suppress such a reaction, it is preferable to adjust the amount of the secondary amine compound (XI) used to a relatively low level, for example, to adjust the molar ratio of the secondary amine compound (XI) to methane to 1 or less, or to not use a base. Alternatively, the produced carbonyl halide may be dissolved in a solvent to prepare a carbonyl halide solution, and the secondary amine compound (XI) or a solution thereof may be added to the solution while maintaining the molar ratio of the carbonyl halide to the secondary amine compound (XI) at more than 1, thereby efficiently producing a carbamoyl halide compound.

[0105] When the target compound is a carbamoyl halide compound, it is preferable to adjust the amount of secondary amine compound (XI) used to a relatively low level, for example, to set the molar ratio of secondary amine compound (XI) to the carbonyl halide produced to 1 or less. However, since it can be difficult to predict the exact amount of carbonyl halide produced, it is preferable to set the molar ratio of secondary amine compound (XI) to the methane used to less than 1. The molar ratio is preferably 0.5 or less, more preferably 0.2 or less, and also preferably 0.001 or more, more preferably 0.05 or more. On the other hand, when the target compound is a urea compound, the ratio is preferably 2 or more, preferably 4 or more, and also preferably 20 or less, more preferably 15 or less.

[0106] The temperature for the reaction of the carbonyl halide with the secondary amine compound (XI) is preferably set lower than the reaction temperature with the alcohol compound, for example, in order to maintain the carbonyl halide in a liquid state. For example, the reaction temperature can be set to 15°C or lower, preferably 10°C or lower, more preferably 5°C or lower, and even more preferably 2°C or lower. There is no particular lower limit to the temperature, but for example, the temperature is preferably -80°C or higher, more preferably -20°C or higher or -15°C or higher.

[0107] When the target compound is a carbamoyl halide compound and a base is used, it is preferable to use one or more bases selected from the heterocyclic aromatic amines and non-nucleophilic strong bases exemplified in the production conditions for the isocyanate compound. When the target compound is a urea compound, it is preferable to set the molar ratio of the secondary amine compound to methane or the generated carbonyl halide to greater than 1. The molar ratio is preferably 1.5 or more, more preferably 2 or more.

[0108] Post-reaction process - NCA production In the above-mentioned method for producing a carbonate compound, it is also possible to produce an amino acid N-carboxylic anhydride (VIII) (NCA) by using an amino acid compound (VII) instead of an alcohol compound.

[0109] [ka]

[0110] [In the formula, R 4 represents an amino acid side chain group in which a reactive group is protected, R 5 is H or P 1 -[-NH-CHR 6 -C(=O)-] l -(In the formula, R 6 indicates an amino acid side chain in which reactive groups are protected, and P 1 represents a protecting group for an 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 or different).

[0111] Post-reaction process - Vilsmeier reagent production Vilsmeier reagent (X) can be produced by reacting carbonyl halide with amide compound (IX). The Vilsmeier reagent can be produced in the same manner as in the above-mentioned method for producing a carbonate compound, except that amide compound (IX) is used instead of an alcohol compound and no base is used.

[0112] [ka]

[0113] [In the formula, R 7 is a hydrogen atom, C 1-6 alkyl group or optionally substituted C 6-12 represents an aromatic hydrocarbon group, R 8 and R 9 independently, C 1-6 alkyl group or optionally substituted C 6-12 represents an aromatic hydrocarbon group, and R 8 and R 9 may be joined together to form a 4- to 7-membered ring structure, X represents a halogeno group selected from the group consisting of chloro, bromo, and iodo; Y - indicates the counter anion.]

[0114] C 6-12 The substituent that the aromatic hydrocarbon group may have is not particularly limited as long as it does not inhibit the reaction according to the present invention. For example, C 1-6 Alkyl group, C 1-6 Examples of the substituents include one or more substituents selected from the group consisting of an alkoxy group, a halogeno group, a nitro group, and a cyano group. The number of substituents is not particularly limited as long as it is substitutable, but can be, for example, 1 to 5, preferably 3 or less, more preferably 2 or less, and even more preferably 1. When the number of substituents is 2 or more, the substituents may be the same or different from each other.

[0115] R 8 and R9 Examples of the 4- to 7-membered ring structure formed by combining with the nitrogen atom include a pyrrolidyl group, a piperidyl group, and a morpholino group.

[0116] Specific examples of the amide compound (IX) include N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), N-methyl-N-phenylformamide, N-methylpyrrolidone (NMP), 1,3-dimethylimidazolidinone (DMI), tetramethylurea, tetraethylurea, and tetrabutylurea, and DMF is preferred from the viewpoints of versatility, cost, and the like.

[0117] Y in formula (X) - Examples of the ions include chloride ions, bromide ions, and iodide ions derived from simple halogen gases, but are not particularly limited.

[0118] The amount of the amide compound used may be adjusted as appropriate within a range in which the reaction proceeds well, and may be, for example, 0.1 mol or more and 100 mol or less per mol of methane.

[0119] When reacting a carbonyl halide with an amide compound, a solvent may be used. The solvent may be added to a composition containing an amide compound. Examples of the solvent include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester-based solvents such as ethyl acetate; aliphatic hydrocarbon solvents such as n-hexane; aromatic hydrocarbon solvents such as benzene, toluene, xylene, and benzonitrile; ether-based solvents such as diethyl ether, tetrahydrofuran, and dioxane; and nitrile-based solvents such as acetonitrile.

[0120] The temperature for reacting the carbonyl halide with the amide compound is not particularly limited and may be adjusted as appropriate, but may be, for example, 0° C. or higher and 120° C. or lower. The temperature is more preferably 10° C. or higher, even more preferably 20° C. or higher, and more preferably 100° C. or lower, and even more preferably 80° C. or lower or 50° C. or lower.

[0121] The time for reacting the carbonyl halide with the amide compound is not particularly limited and may be adjusted as appropriate, but is preferably, for example, 0.5 hours or more and 50 hours or less. The reaction time is more preferably 1 hour or more, even more preferably 5 hours or more, and more preferably 30 hours or less, and even more preferably 20 hours or less. Furthermore, even after the production of the carbonyl halide is complete, stirring of the reaction solution may be continued, for example, until consumption of the amide compound is confirmed.

[0122] The Vilsmeier-Haack reaction using a Vilsmeier reagent can convert aromatic compounds with activated groups into aldehydes or ketones. It is also known that the Vilsmeier reagent converts the carboxyl group of carboxylic acid compounds into haloformyl groups. Furthermore, by reacting a hydroxyl-containing compound with the Vilsmeier reagent, a formic acid ester can be obtained. The inventors have also discovered that when a carbamoyl compound with a carbamoyl group (-C(=O)-NH2) is placed in the presence of DMF, the Vilsmeier reagent likely acts as a dehydrating agent to produce a nitrile compound with a cyano group. Examples of carbamoyl compounds include R 1 -C(=O)-NH2, and examples of nitrile compounds include R 1 -CN is one example.

[0123] Aromatic compounds having an active group (hereinafter referred to as "activated aromatic compounds") are aromatic compounds activated by a substituent or the like. For example, amino groups containing alkylamino groups substituted with alkyl groups, and hydroxyl groups, strongly activate aromatic compounds. In addition, alkylcarbonylamino groups (-NH(C=O)R), alkylcarbonyloxy groups (-O(C=O)R), ether groups (-OR), and alkyl groups (-R) (where R represents an alkyl group and C 1-6 (Alkyl groups are preferred) and aromatic groups also activate aromatic compounds. Hereinafter, these substituents will be referred to as activating groups. Compounds with condensed aromatic rings and extended conjugated systems, such as anthracene, are also activated and undergo aldehyde or ketonization with Vilsmeier reagent. It is believed that the π electrons of the activated sites react electrophilically with the Vilsmeier reagent, resulting in aldehyde or ketonization.

[0124] The activated aromatic compound is not particularly limited as long as it is an activated compound that can be converted into an aldehyde or a ketone by a Vilsmeier reagent. For example, C benzene or naphthalene substituted with the above-mentioned activating group can be used. 6-12 Examples of such heteroaryl groups include aromatic hydrocarbons; fused aromatic hydrocarbons, such as phenanthrene and anthracene, which may be substituted with the above-mentioned activating groups; 5-membered heteroaryl groups, such as pyrrole, imidazole, pyrazole, thiophene, furan, oxazole, isoxazole, thiazole, isothiazole, and thiadiazole, which may be substituted with the above-mentioned activating groups; 6-membered heteroaryl groups, such as pyridine, pyrazine, pyrimidine, and pyridazine, which may be substituted with the above-mentioned activating groups; and fused heteroaryl groups, such as indole, isoindole, quinoline, isoquinoline, benzofuran, isobenzofuran, and chromene, which may be substituted with the above-mentioned activating groups.

[0125] The substrate compounds of the above reaction, that is, the active group-containing aromatic compound, the carboxylic acid compound, and the hydroxyl group-containing compound, may be added to the reaction liquid after blowing the carbonyl halide-containing gas into the composition containing the amide compound, or may be added to the reaction liquid before or during blowing the carbonyl halide-containing gas into the composition containing the amide compound.

[0126] The amounts of the active group-containing aromatic compound, carboxylic acid compound, and hydroxyl group-containing compound used may be adjusted as appropriate, for example, to 0.1 to 1.0 times by mole relative to the amide compound.

[0127] Vilsmeier reagents are also useful for obtaining carboxylic acid halides from carboxylic acid compounds. When a carboxylic acid compound is halogenated, the Vilsmeier reagent converts it back into an amide compound. Reacting the resulting carboxylic acid halide with an alcohol compound yields an ester compound, while reacting with a carboxylic acid yields a carboxylic acid anhydride. It is believed that if a carboxylic acid compound and a base are used instead of an amide compound, the carboxylic acid compound anionized by the base can be directly converted into a carboxylic acid halide by a carbonyl halide. Such carboxylic acid halides can also be used to produce ester compounds and carboxylic acid anhydrides.

[0128] Post-reaction process - production of urea compounds A urea compound can be produced by reacting a carbonyl halide with a primary amine compound or a secondary amine compound. Specifically, in the above-mentioned method for producing an isocyanate compound or a carbamoyl halide compound, the amount of the primary amine compound or the secondary amine compound is adjusted to be relatively large, for example, by setting the molar ratio of the primary amine compound or the secondary amine compound to methane to 1 or more, thereby mainly producing a urea compound. It is believed that the isocyanate compound or the carbamoyl halide compound is produced by reacting the carbonyl halide with the primary amine compound or the secondary amine compound, and the urea compound is produced by further reacting the isocyanate compound or the carbamoyl halide compound with the primary amine compound or the secondary amine compound. The molar ratio is preferably 1.5 or more, more preferably 2 or more or 4 or more, and is preferably 20 or less, more preferably 15 or less.

[0129] As the primary amine compound, the primary amine compound (V):R exemplified in the method for producing the isocyanate compound is 3 -(NH2) m As the secondary amine compound, the secondary amine compound (XI):R exemplified in the method for producing the carbamoyl halide compound can be used. 21 -(NH-R 22 ) m can be used.

[0130] When a primary amine compound or a secondary amine compound is used in this reaction step, it is preferable to use a base because the reaction may be inhibited by the formation of a salt with the by-product hydrogen halide. The base is preferably one or more bases selected from heterocyclic aromatic amines and non-nucleophilic strong bases. The amount of base used may be adjusted appropriately within a range in which the reaction proceeds smoothly, and can be, for example, 1 mol or more and 10 mol or less per mol of methane.

[0131] The reaction of the carbonyl halide with the primary amine compound (V) or the secondary amine compound (XI) produces an isocyanate compound or a carbamoyl halide compound, which is then thought to react with the primary amine compound (V) or the secondary amine compound (XI) to produce a urea compound.

[0132] Post-processing Since many carbonyl halides are harmful, it is preferable to prevent the generated carbonyl halide from leaking out of the system. For example, it is preferable to introduce the gas phase discharged from the reaction vessel in which the generated carbonyl halide is reacted into an alcohol trap, and then introduce the gas phase discharged from the alcohol trap into an alkali trap. The alcohol trap may be cooled to a temperature within a range in which the alcohol used does not solidify, for example, to a temperature of about −80° C. or higher and about 50° C. or lower. In addition, for example, an aqueous sodium hydroxide solution or a saturated aqueous sodium bicarbonate solution can be used for the alkali trap.

[0133] When the compound obtained from the carbonyl halide is relatively unstable, such as an isocyanate compound, an additional reaction substrate compound may be added to the reaction solution obtained by reacting the carbonyl halide. Alternatively, when the compound obtained from the carbonyl halide is relatively stable, such as a carbonate compound, the target compound may be purified from the reaction solution. For example, a water-insoluble organic solvent such as chloroform and water may be added to the reaction solution to separate the layers, and the organic phase may be dried over anhydrous sodium sulfate, anhydrous magnesium sulfate, or the like, concentrated under reduced pressure, and further purified by chromatography or the like.

[0134] This application claims the benefit of priority based on Japanese Patent Application No. 2023-176533, filed on October 12, 2023. The entire contents of the specification of Japanese Patent Application No. 2023-176533, filed on October 12, 2023, are incorporated herein by reference. [Example]

[0135] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples, and it is possible to carry out the invention by making appropriate modifications within the scope of the above and below-described aims, and all such modifications are included in the technical scope of the present invention.

[0136] Example 1: Synthesis of carbonyl chloride from high-purity methane gas [ka] The reaction system shown in Figure 1 was constructed, and the following reagents and equipment were used. Methane: Sumitomo Seika Chemicals (purity > 99.0%) Calcium hypochlorite: Nacalai Tesque (available chlorine > 60%) Hydrochloric acid: Nacalai Tesque (concentration: 35%) 1-Butanol: Fujifilm Wako Pure Chemical Industries, Ltd. (purity >99.0%) Calcium chloride: Fujifilm Wako Pure Chemical Industries, Ltd. (purity >95.0%) Air pump: "Nisso Silent β-60 Air Pump" manufactured by Marukan Mass flow controller: "MODEL8500MC" manufactured by KOFLOC Ultrasonic cleaner: "1510J-MT" manufactured by BRANSONIC Hot plate: "C-MAG HP7" manufactured by IKA Calcium hypochlorite (11.4 g, 80 mmol) was placed in a three-necked flask immersed in a water bath, and while irradiating the flask with 70 W, 42 kHz ultrasound using an ultrasonic cleaner, 11.3 mol / L hydrochloric acid was added using a syringe pump at an injection rate of 228.1 μL / min at room temperature, thereby continuously generating chlorine gas according to the following formula. Ca(ClO)2·3H2O + 4HCl → CaCl2+ 2Cl2+ 5H2O An air pump was used to send air into a gas drying tube (inner diameter 16 mm × length 265 mm) filled with silica gel for drying. The flow rate of the dried air was adjusted using a mass flow controller as shown in Table 1 and sent to the three-neck flask. The resulting chlorine-air mixed gas was dried by passing it through a gas drying tube (inner diameter 16 mm × length 265 mm) filled with calcium chloride. This was then combined in a T-mixer with methane gas (supplied from a cylinder) whose flow rate was controlled by a mass flow controller to prepare a chlorine-air-methane mixed gas. This gas was then sent into a PTFE coil heater and then into the flow photoreactor. The flow photoreactor was a rectangular borosilicate glass vessel (external dimensions: 220 mm × 185 mm × 30 mm, wall thickness: 3.3 mm, internal volume: 891 cm). 3 ), or a cylindrical borosilicate glass container (external dimensions: φ55 mm x 150 mm, plate thickness: 2.0 mm, internal volume: 300 cm 3 ), 365nm LED lamp (Polarstar, peak wavelength: 365nm, 45W, LED (14cm x 18cm), illuminance: 36.5mW / cm 2 ), or a 405 nm LED lamp (Polarstar, peak wavelength: 405 nm, 30 W, LED (14 cm x 18 cm), illuminance: 57.2 to 54.5 mW / cm 2 The flow rate of the air and methane gases and the rate of chlorine generation were adjusted to control the residence time of the reaction gases in the flow photoreactor. The gaseous product generated in the system was blown into 1-butanol placed in a first reactor to obtain a mixed product of chloroformate and carbonate. The gas from the first reactor was supplied to a second reactor, which also contained 1-butanol. The reaction solutions in the first and second reactors were 1 The amounts of butyl chloroformate and dibutyl carbonate produced were determined by H NMR analysis, and the amount of carbonyl chloride produced was calculated. The experimental conditions are shown in Table 1, and the experimental results are shown in Table 2. In addition, the reaction gas passed through the photoreactor was blown into CDCl3 at 0°C, 13 The results are shown in Figure 2.

[0137] [Table 1]

[0138] [Table 2]

[0139] As shown in Figure 2, carbonyl chloride was confirmed in the gas obtained by reacting methane, chlorine, and oxygen. Other peaks are those of the solvent, CDCl3, etc.

[0140] As can be seen from the results of Experiments 1 to 3, compared to Experiment 2, even if the temperature of the photoreaction vessel was increased from room temperature to 100°C (Experiment 1), or even if the photoreaction vessel was cooled to 0°C (Experiment 3), the amounts of chloroformate and carbonate produced did not change significantly, and therefore it was thought that the amount of carbonyl chloride produced would also not change significantly. Furthermore, when a relatively small photoreactor was used (Experiment No. 4), the yield of chloroformate ester decreased somewhat, possibly due to a shorter residence time of the reaction gas, but no significant decrease was observed, suggesting that the amount of carbonyl chloride produced did not decrease significantly either. Furthermore, even when the irradiation light was changed to light with a relatively long wavelength and low energy (Experiment No. 5), the yield of chloroformate ester decreased slightly, but no significant decrease was observed, suggesting that the amount of carbonyl chloride produced did not decrease significantly. Furthermore, when the amount of air introduced into the high-purity methane gas was increased to reduce the methane concentration in the reaction gas (Experiment Nos. 6 and 7), a tendency for the conversion rate of methane to carbonyl chloride to increase was observed.

[0141] Example 2: Synthesis of carbonyl chloride from city gas The reaction system shown in Figure 1 was used. Calcium hypochlorite (18.5 g, 130 mmol) was placed in a three-necked flask immersed in an ice bath. Chlorine gas was continuously generated by adding 2.1 mmol / L hydrochloric acid at a rate of 370 μL / min using a syringe pump at room temperature while irradiating the flask with 70 W, 42 kHz ultrasonic waves using an ultrasonic cleaner. Air was dried by an air pump through a silica gel-filled gas drying tube (16 mm inner diameter x 265 mm length) and then pumped into the three-neck flask at a flow rate of 55 mL / min (O2 flow rate: 0.46 mmol / min) using a mass flow controller. The resulting chlorine-air mixture was combined with city gas, the flow rate of which was controlled by a mass flow controller to 13.2 mL / min (methane flow rate: 0.55 mmol / min), and pumped into a PTFE coil heater. A chlorine-air-city gas mixture was prepared and pumped into the flow photoreactor. The city gas was provided by Osaka Gas Co., Ltd. and had a composition of approximately 88.9 vol% methane, 6.8 vol% ethane, 3.1 vol% propane, and 1.2 vol% butane. The flow photoreactor was a rectangular borosilicate glass vessel (external dimensions: 220 mm × 185 mm × 30 mm, plate thickness: 3.3 mm, internal volume: 891 cm). 3 ) and a 365 nm LED lamp (Polarstar, peak wavelength: 365 nm, 45 W, LED (14 cm × 18 cm), illuminance: 54.7–54.4 mW / cm 2 ) The reaction time was 2 hours, during which the amount of methane supplied to the flow photoreactor was 50 mmol and the amount of chlorine supplied to the flow photoreactor was 56 mmol. The residence time of the reaction gas in the flow photoreactor was 9 minutes. During the reaction, the temperature of the flow photoreactor and the coil heater were not controlled. The gaseous product generated in the reaction system was blown into 1-butanol placed in a first reaction vessel to obtain a mixed product of chloroformate and carbonate. The gas from the first reaction vessel was supplied to a second reaction vessel containing 1-butanol as well. The reaction solutions in the first and second reaction vessels were 1The amount of carbonyl chloride produced was determined from the amounts of ethyl chloroformate and dibutyl carbonate produced by H NMR analysis. The results are shown in Table 3.

[0142] [Table 3]

[0143] As shown in Table 3, carbonyl chloride was obtained from methane containing other hydrocarbon gases such as ethane. Since the conversion rate of methane to carbonyl chloride was not significantly different from that in Example 1, it is believed that other hydrocarbon gases such as ethane were decomposed into compounds other than carbonyl chloride.

[0144] Example 3: Synthesis of carbonyl chloride from biogas The reaction system shown in Figure 1 was used. Calcium hypochlorite was added to a three-neck flask immersed in an ice bath. While irradiating the flask with 70W, 42kHz ultrasonic waves using an ultrasonic cleaner, 2.1mmol / L hydrochloric acid was added at room temperature at a rate of 370μL / min using a syringe pump to continuously generate chlorine gas. The amount of calcium hypochlorite was 18.5g (130mmol) in Experiments 1 and 2, and 129.5g (906mmol) in Experiment 3, which used a longer reaction time. Air pumped from an air pump was dried through a silica gel-filled gas drying tube (16 mm inner diameter x 265 mm length) and then pumped into the three-neck flask at a flow rate of 55 mL / min (O2 flow rate: 0.46 mmol / min) using a mass flow controller. The resulting chlorine-air mixture was combined with biogas (TLF-06472, Air Water Corporation) at a flow rate of 24.8 mL / min (methane flow rate: 0.55 mmol / min) using a mass flow controller, and pumped into a PTFE coil heater. A chlorine-air-biogas mixture was prepared and pumped into the flow photoreactor. The biogas used had a composition of 53 vol% methane, 34 vol% carbon dioxide, 8.3 vol% nitrogen, and 2.5 vol% oxygen. The flow photoreactor was a rectangular borosilicate glass vessel (external dimensions: 220 mm × 185 mm × 30 mm, plate thickness: 3.3 mm, internal volume: 891 cm). 3 ) and a 365 nm LED lamp (Polarstar, peak wavelength: 365 nm, 45 W, LED (14 cm × 18 cm), illuminance: 54.7–54.4 mW / cm 2 ) or a 405 nm LED lamp (Polarstar, peak wavelength: 405 nm, 30 W, LED (14 cm × 18 cm), illuminance: 57.2 to 54.5 mW / cm 2 ) The residence time of the reaction gas in the flow photoreactor was 11.2 minutes. During the reaction, the temperature was not controlled by the flow photoreactor or the coil heater. The gaseous product generated in the reaction system was blown into 1-butanol placed in a first reaction vessel to obtain a mixed product of chloroformate and carbonate. The gas from the first reaction vessel was supplied to a second reaction vessel containing 1-butanol as well. The reaction solutions in the first and second reaction vessels were 1 The amount of carbonyl chloride produced was determined from the amounts of ethyl chloroformate and dibutyl carbonate produced by H NMR analysis. The experimental conditions are shown in Table 4, and the experimental results are shown in Table 5.

[0145] [Table 4]

[0146] [Table 5]

[0147] As shown in Table 5, carbonyl chloride was obtained from biogas with a good conversion rate. The reason for this is thought to be that biogas contains relatively large amounts of inert gases such as carbon dioxide and nitrogen, and the concentration of methane is relatively low, which suppresses excessive chlorination and oxidation reactions of methane.

[0148] Example 4: Synthesis of carbonyl chloride from biogas The reaction system used was the one shown in Fig. 1. However, the scale of the experiment was larger than that of Example 3. Calcium hypochlorite (39.0 g, 273 mmol) was added to a three-necked flask immersed in an ice bath. Chlorine gas was continuously generated by adding 2.1 mmol / L hydrochloric acid at a rate of 1029 μL / min using a syringe pump at room temperature while irradiating the flask with 70 W, 42 kHz ultrasonic waves using an ultrasonic cleaner. Air delivered by an air pump was dried through a gas drying tube (inner diameter 16 mm x length 265 mm) filled with silica gel and then fed into the three-neck flask at the flow rate shown in Table 6 using a mass flow controller. The resulting chlorine-air mixed gas was combined with biogas (TLF-06472, Air Water Corporation), the flow rate of which was controlled by a mass flow controller, and fed into a PTFE coil heater to prepare a chlorine-air-biogas mixed gas, which was then fed into the flow photoreactor. The biogas used had a composition of methane: 53 vol%, carbon dioxide: 34 vol%, nitrogen: 8.3 vol%, and oxygen: 2.5 vol%. The flow photoreactor was housed in a rectangular borosilicate glass vessel (external dimensions: 220 mm x 185 mm x 50 mm, plate thickness: 3.3 mm, internal volume: 1652 cm). 3), or two square borosilicate glass vessels (external dimensions: 220 mm x 90 mm x 50 mm, plate thickness: 3.3 mm, internal volume: 772 cm) connected in series. 3 ) and a 365 nm LED lamp (Polarstar, peak wavelength: 365 nm, 45 W, LED (14 cm × 18 cm), illuminance: 54.7–54.4 mW / cm 2 ) During the reaction, the temperature was not controlled by the flow photoreactor and the coil heater. The gaseous product generated in the reaction system was blown into 1-butanol placed in a first reaction vessel to obtain a mixed product of chloroformate and carbonate. The gas from the first reaction vessel was supplied to a second reaction vessel containing 1-butanol as well. The reaction solutions in the first and second reaction vessels were 1 The amount of carbonyl chloride produced was determined from the amounts of ethyl chloroformate and dibutyl carbonate produced by H NMR analysis. The experimental conditions are shown in Table 6, and the experimental results are shown in Table 7.

[0149] [Table 6]

[0150] [Table 7]

[0151] As shown in the results in Table 7, even when the scale of the experiment was increased, carbonyl chloride could be produced in good yield from biogas, chlorine gas, and air.

[0152] Example 5: Synthesis of carbonyl chloride with the use of ozone The reaction system shown in Figure 1 was used. Calcium hypochlorite (39.0 g, 273 mmol) was added to a three-necked flask immersed in an ice bath. Chlorine gas was continuously generated by adding 2.1 mmol / L hydrochloric acid at a rate of 1029 μL / min using a syringe pump at room temperature while irradiating the flask with 70 W, 42 kHz ultrasonic waves using an ultrasonic cleaner. Ozone was generated using an ozone generator ("R200" manufactured by WUOAUM). The ozone generation rate was 200 mg / h. The ozone-containing air generated by the ozone generator was dried through a gas drying tube (inner diameter 16 mm x length 265 mm) filled with silica gel and then delivered to the three-neck flask using a mass flow controller at the flow rate shown in Table 8. The resulting chlorine-air mixture was combined with biogas ("TLF-06472" manufactured by Air Water Corporation) whose flow rate was controlled by a mass flow controller, and delivered to a PTFE coil heater. A chlorine-air-biogas mixture was prepared and delivered to the flow photoreactor. The biogas used had a composition of 53 vol% methane, 34 vol% carbon dioxide, 8.3 vol% nitrogen, and 2.5 vol% oxygen. The flow photoreactor was a rectangular borosilicate glass vessel (external dimensions: 220 mm × 185 mm × 50 mm, plate thickness: 3.3 mm, internal volume: 1652 cm). 3 ) and a 365 nm LED lamp (Polarstar, peak wavelength: 365 nm, 45 W, LED (14 cm × 18 cm), illuminance: 54.7–54.4 mW / cm 2 ) During the reaction, the temperature was not controlled by the flow photoreactor and the coil heater. The gaseous products generated in the reaction system were blown into 1-butanol placed in the first reaction vessel to obtain a mixed product of chloroformate and carbonate. The gas from the first reactor was supplied to a second reactor containing 1-butanol. 1 The amount of carbonyl chloride produced was determined from the amounts of ethyl chloroformate and dibutyl carbonate produced by H NMR analysis. The experimental conditions and results are shown in Table 8.

[0153] [Table 8]

[0154] Although ozone was used in combination with oxygen, the production efficiency of carbonyl chloride was not significantly improved.

[0155] Example 6: Synthesis of carbonate [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (11.9 g, 83 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a flow rate of 388.9 μL / min to continuously generate chlorine gas. Dry air dehydrated through silica gel was then pumped into the flask at a flow rate of 55.5 mL / min (O2 flow rate: 0.49 mmol / min) using a mass flow controller, resulting in a chlorine-air mixture. The resulting mixture was then mixed with biogas at a flow rate of 24.8 mL / min (CH4 flow rate: 0.55 mmol / min). The resulting mixed gas was sent to a box-type photoreactor (volume: 891 mL) measuring 220 mm x 185 mm x 30 mm, where it was irradiated with light from a 365 nm LED lamp (45 W), yielding a photooxidized gas containing mainly carbonyl chloride and hydrogen chloride. The resulting photooxidation gas was blown into an acetonitrile solution (50 mL) containing 1-hexanol (30 mmol, 3.1 g) and pyridine (240 mmol, 19.2 mL) and stirred at room temperature. The gas discharged from the reaction system was sent to an aqueous sodium bicarbonate solution to decompose and treat the photooxidation products, such as hydrogen chloride and excess carbonyl chloride. After 55 minutes of biogas injection (CH4 amount: 30 mmol) and 1 hour 25 minutes of 365 nm light irradiation, the reaction system was stopped and air was pumped in for 30 minutes to expel any remaining gases in the reaction system. After the reaction was completed, 1,2-dichloroethane (10 mmol, 0.8 mL) was added to the solution as an internal standard. 1 Analysis was performed by 1 H NMR. 1 1 H NMR measurement confirmed the formation of dihexyl carbonate in the solution after the reaction (NMR yield: 99%). The resulting reaction solution was washed with 1 M hydrochloric acid and water and extracted with CHCl. The resulting organic layer was dried over anhydrous sodium sulfate, and the solvent was removed by atmospheric distillation to obtain dihexyl carbonate as a colorless liquid (yield: 3.2 g, 14.0 mmol, 93%).

[0156] Example 7: Synthesis of urea derivatives [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (11.9 g, 83 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a flow rate of 388.9 μL / min to continuously generate chlorine gas. Dry air dehydrated through silica gel was then pumped into the flask at a flow rate of 55.5 mL / min (O2 flow rate: 0.49 mmol / min) using a mass flow controller, resulting in a chlorine-air mixture. The resulting mixture was then mixed with biogas at a flow rate of 24.8 mL / min (CH4 flow rate: 0.55 mmol / min). The resulting mixed gas was sent to a box-type photoreactor (volume: 891 mL) measuring 220 mm x 185 mm x 30 mm, where it was irradiated with light from a 365 nm LED lamp (45 W), yielding a photooxidized gas containing mainly carbonyl chloride and hydrogen chloride. The resulting photooxidation gas was blown into an acetonitrile solution (50 mL) containing aniline (30 mmol, 3.0 g) and pyridine (120 mmol, 9.6 mL) and stirred at room temperature. The gas discharged from the reaction system was sent to an aqueous sodium bicarbonate solution to decompose and treat the photooxidation products, such as hydrogen chloride and excess carbonyl chloride. After 55 minutes of biogas injection (CH4 amount: 30 mmol) and 1 hour 25 minutes of 365 nm light irradiation, the reaction system was stopped and air was pumped in for 30 minutes to expel any remaining gas. After the reaction was completed, the solution was washed with 1 M hydrochloric acid and water and extracted with CHCl. The resulting organic layer was dried over anhydrous sodium sulfate, the solvent was removed by vacuum distillation, and the residue was purified using a glass tube oven (Shibata Scientific Co., Ltd.) to obtain a colorless liquid diphenylurea (yield: 2.8 g, 13.0 mmol, 88%).

[0157] Example 8: Synthesis of N-protected amino acids [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (13.0 g, 91 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a flow rate of 388.9 μL / min to continuously generate chlorine gas. Dry air dehydrated through silica gel was then pumped into the flask at a flow rate of 40.0 mL / min (O2 flow rate: 0.35 mmol / min) using a mass flow controller, resulting in a chlorine-air mixture. The resulting mixture was then mixed with biogas at a flow rate of 24.8 mL / min (CH4 flow rate: 0.55 mmol / min). The resulting mixed gas was pumped into a 220 mm x 185 mm x 30 mm box-type photoreactor (volume: 891 mL) and irradiated with a 365 nm LED lamp (45 W). Benzyl alcohol was injected at a flow rate of 25.8 μL / min using a syringe pump through a T-shaped mixer connected to the outlet of the box-type photoreactor, and the reaction was carried out in a PTFE tube (inner diameter: 2.4 mm, length: 1000 mm, volume: 4.52 mL). The resulting reaction mixture was added dropwise to a mixed solvent containing L-aspartic acid (5 mmol, 0.7 g), potassium carbonate (120 mmol, 23.8 g), water (30 mL), and acetonitrile (10 mL) and stirred at room temperature for 18 hours. After 1 hour of biogas injection (CH4 content: 33.3 mmol) and 1 hour and 30 minutes of 365 nm light irradiation, the reaction system was stopped and air was pumped in for 30 minutes to expel any remaining sample gas. The gas discharged from the reaction system was pumped into an aqueous sodium bicarbonate solution to decompose and treat photooxidation products such as hydrogen chloride and excess carbonyl chloride. After the reaction was completed, 1,1,2,2-tetrachloroethane (5 mmol, 0.53 mL) was added to the solution as an internal standard. 1 Analysis was performed by 1 H NMR. 1 1 H NMR measurement confirmed the production of N-Cbz-L-aspartic acid in the solution after the reaction (NMR yield: 20%). It is believed that methane, chlorine, and oxygen reacted to produce carbonyl chloride, which then reacted with benzyl alcohol to produce benzyloxycarbonyl chloride, which then reacted with L-aspartic acid.

[0158] Example 9: Synthesis of isocyanate compounds [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (19.5 g, 136 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a flow rate of 388.9 μL / min to continuously generate chlorine gas. Dry air dehydrated through silica gel was then pumped into the flask at a flow rate of 55.5 mL / min (O2 flow rate: 0.49 mmol / min) using a mass flow controller, resulting in a chlorine-air mixture. The resulting mixture was then mixed with biogas at a flow rate of 24.8 mL / min (CH4 flow rate: 0.55 mmol / min). The resulting mixed gas was sent to a box-type photoreactor (volume: 891 mL) measuring 220 mm x 185 mm x 30 mm, where it was irradiated with light from a 365 nm LED lamp (45 W), yielding a photooxidized gas containing mainly carbonyl chloride and hydrogen chloride. The resulting photooxidation gas was blown into a toluene solution (50 mL) of hexylamine hydrochloride (0.7 g, 5 mmol) and stirred at 100°C. The gas discharged from the reaction system was sent to an aqueous sodium bicarbonate solution to decompose and treat photooxidation products such as hydrogen chloride and excess carbonyl chloride. After 1 hour and 30 minutes of biogas injection (CH4 content: 50 mmol) and 2 hours of 365 nm light irradiation, the reaction system was stopped and air was pumped into the system for 30 minutes to expel any remaining gas. After the reaction was completed, 1,1,2,2-tetrachloroethane (1.1 mL, 10 mmol) was added to the solution as an internal standard. 1 Analysis was performed by 1 H NMR. 1 1 H NMR measurement confirmed the production of 1-isocyanatehexane in the solution after the reaction (NMR yield: 87%).

[0159] Example 10: Synthesis of isocyanate compounds [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (19.5 g, 136 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a flow rate of 388.9 μL / min to continuously generate chlorine gas. Dry air dehydrated through silica gel was then pumped into the flask at a flow rate of 40.0 mL / min (O2 flow rate: 0.35 mmol / min) using a mass flow controller, resulting in a chlorine-air mixture. The resulting mixture was then mixed with biogas at a flow rate of 24.8 mL / min (CH4 flow rate: 0.55 mmol / min). The resulting mixed gas was sent to a box-type photoreactor (volume: 891 mL) measuring 220 mm x 185 mm x 30 mm, where it was irradiated with light from a 365 nm LED lamp (45 W), yielding a photooxidized gas containing mainly carbonyl chloride and hydrogen chloride. The resulting photooxidation gas was blown into toluene (200 mL) in a three-necked round-bottom flask and stirred at 0° C. The gas discharged from the reaction system was sent to an aqueous sodium bicarbonate solution to decompose and treat photooxidation products such as hydrogen chloride and excess carbonyl chloride. After 1.5 hours of biogas injection (CH4 content: 50 mmol) and 2 hours of 365 nm light irradiation, the reaction system was stopped, and 4,4'-diaminodiphenylmethane (5 mmol, 1.0 g) dissolved in toluene (20 mL) was injected into the toluene containing the photooxidation gas and stirred. Subsequently, pyridine (50 mmol, 4.0 g) dissolved in toluene (10 mL) was injected and stirred. The reaction vessel was then heated to 60 °C and air was introduced for 30 minutes to expel any remaining gases in the system. After the reaction was completed, 1,1,2,2-tetrachloroethane (1.1 mL, 10 mmol) was added to the solution as an internal standard. 1 Analysis was performed by 1 H NMR. 1 1 H NMR measurement confirmed the production of methylenediphenyl 4,4′-diisocyanate in the solution after the reaction (NMR yield: 38%).

[0160] Example 11: Vilsmeier reaction → esterification [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (11.9 g, 83 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a flow rate of 388.9 μL / min to continuously generate chlorine gas. Dry air dehydrated through silica gel was then pumped into the flask at a flow rate of 55.5 mL / min (O2 flow rate: 0.49 mmol / min) using a mass flow controller, resulting in a chlorine-air mixture. The resulting mixture was then mixed with biogas at a flow rate of 24.8 mL / min (CH4 flow rate: 0.55 mmol / min). The resulting mixed gas was sent to a box-type photoreactor (volume: 891 mL) measuring 220 mm x 185 mm x 30 mm, where it was irradiated with light from a 365 nm LED lamp (45 W), yielding a photooxidized gas containing mainly carbonyl chloride and hydrogen chloride. The resulting photooxidation gas was blown into an acetonitrile solution (50 mL) containing benzoic acid (15 mmol, 1.8 g) and N,N-dimethylformamide (30 mmol, 2.3 mL) and stirred at 30°C. The gas discharged from the reaction system was sent to an aqueous sodium bicarbonate solution to decompose and treat photooxidation products such as hydrogen chloride and excess carbonyl chloride. After 55 minutes of biogas injection (CH4: 30 mmol) and 1 hour 25 minutes of 365 nm light irradiation, the reaction system was stopped and air was pumped in for 30 minutes to expel any remaining gases. Next, 1-butanol (60 mmol, 5.5 mL) and pyridine (120 mmol, 9.6 mL) were added at 0 °C, and the mixture was stirred at room temperature for 1 hour. After the reaction was completed, 1,2-dichloroethane (10 mmol, 0.8 mL) was added to the solution as an internal standard. 1 Analysis was performed by 1 H NMR. 1H NMR analysis confirmed the formation of butyl benzoate in the reaction solution (NMR yield: >99%). The solvent was removed from the resulting reaction solution by distillation at atmospheric pressure at 90-150°C. Subsequently, silica gel column chromatography (eluent: hexane / ethyl acetate = 5 / 1) yielded butyl benzoate as a colorless liquid (yield: 80%, yield: 2.1 g, 12 mmol).

[0161] Example 12: Vilsmeier reaction → amidation [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (11.9 g, 83 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a flow rate of 388.9 μL / min to continuously generate chlorine gas. Dry air dehydrated through silica gel was then pumped into the flask at a flow rate of 55.5 mL / min (O2 flow rate: 0.49 mmol / min) using a mass flow controller, resulting in a chlorine-air mixture. The resulting mixture was then mixed with biogas at a flow rate of 24.8 mL / min (CH4 flow rate: 0.55 mmol / min). The resulting mixed gas was sent to a box-type photoreactor (volume: 891 mL) measuring 220 mm x 185 mm x 30 mm, where it was irradiated with light from a 365 nm LED lamp (45 W), yielding a photooxidized gas containing mainly carbonyl chloride and hydrogen chloride. The resulting photooxidation gas was blown into an acetonitrile solution (50 mL) containing benzoic acid (15 mmol, 1.8 g) and N,N-dimethylformamide (30 mmol, 2.3 mL) and stirred at 30°C. The gas discharged from the reaction system was sent to an aqueous sodium bicarbonate solution to decompose and treat photooxidation products such as hydrogen chloride and excess carbonyl chloride. After 55 minutes of biogas injection (CH4: 30 mmol) and 1 hour 25 minutes of 365 nm light irradiation, the reaction system was stopped and air was pumped in for 30 minutes to expel any remaining gases. Next, aniline (60 mmol, 5.5 mL) and pyridine (120 mmol, 9.6 mL) were added at 0 °C, and the mixture was stirred at room temperature for 2 hours. After the reaction was completed, 1,2-dichloroethane (10 mmol, 0.8 mL) was added to the solution as an internal standard. 1 Analysis was performed by 1 H NMR. 1 H NMR analysis confirmed the formation of benzanilide in the reaction solution (NMR yield: >99%). 1M hydrochloric acid and dichloromethane were added to the resulting reaction solution, and the mixture was separated. The organic layer was dried over anhydrous sodium sulfate, and the solvent was removed by distillation under reduced pressure to obtain benzanilide as a red solid (yield: 84%, yield: 2.5 g, 13 mmol).

[0162] Example 13: Formylation by Vilsmeier reaction [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (11.9 g, 83 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a flow rate of 388.9 μL / min to continuously generate chlorine gas. Dry air dehydrated through silica gel was then pumped into the flask at a flow rate of 55.5 mL / min (O2 flow rate: 0.49 mmol / min) using a mass flow controller, resulting in a chlorine-air mixture. The resulting mixture was then mixed with biogas at a flow rate of 24.8 mL / min (CH4 flow rate: 0.55 mmol / min). The resulting mixed gas was sent to a box-type photoreactor (volume: 891 mL) measuring 220 mm x 185 mm x 30 mm, where it was irradiated with light from a 365 nm LED lamp (45 W), yielding a photooxidized gas containing mainly carbonyl chloride and hydrogen chloride. The resulting photooxidation gas was blown into an acetonitrile solution (50 mL) containing N,N-dimethylformamide (50 mmol, 3.8 mL) and stirred at 30°C. The gas discharged from the reaction system was sent to an aqueous sodium bicarbonate solution to decompose and treat photooxidation products such as hydrogen chloride and excess carbonyl chloride. After 1 hour and 30 minutes of biogas injection (CH4 content: 50 mmol) and 2 hours of 365 nm light irradiation, the reaction system was stopped and air was pumped in for 30 minutes to expel any remaining gas. Next, 2-methylthiophene (10 mmol, 1.9 g) was added at 0 °C and the mixture was stirred at 70 °C for 30 minutes. After that, aqueous sodium carbonate solution (80 mL, 240 mmol) was added to the reaction mixture and stirred at room temperature for 30 minutes. After the reaction was completed, water and dichloromethane were added to the reaction mixture, and the mixture was separated. The organic layer was dried over anhydrous sodium sulfate, and the solvent was removed by distillation under reduced pressure to obtain 5-methylthiophene-2-carboxaldehyde as a yellow liquid (yield: 85%, yield: 1.1 g, 8.5 mmol).

[0163] Example 14: Synthesis of carbamoyl chloride [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (11.9 g, 83 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a flow rate of 388.9 μL / min to continuously generate chlorine gas. Dry air dehydrated through silica gel was then pumped into the flask at a flow rate of 55.5 mL / min (O2 flow rate: 0.49 mmol / min) using a mass flow controller, resulting in a chlorine-air mixture. The resulting mixture was then mixed with biogas at a flow rate of 24.8 mL / min (CH4 flow rate: 0.55 mmol / min). The resulting mixed gas was sent to a box-type photoreactor (volume: 891 mL) measuring 220 mm x 185 mm x 30 mm, where it was irradiated with light from a 365 nm LED lamp (45 W), yielding a photooxidized gas containing mainly carbonyl chloride and hydrogen chloride. The resulting photooxidation gas was blown into an acetonitrile solution (50 mL) containing N-methylaniline (3 mmol, 0.32 g) and N,N-diisopropylethylamine (80 mmol, 14 mL) and stirred at room temperature. The gas discharged from the reaction system was sent to an aqueous sodium bicarbonate solution to decompose and treat the photooxidation products, such as hydrogen chloride and excess carbonyl chloride. After 55 minutes of biogas injection (CH4 amount: 30 mmol) and 1 hour 25 minutes of 365 nm light irradiation, the reaction system was stopped and air was pumped in for 30 minutes to expel any remaining gas in the system. After the reaction was completed, 1,2-dichloroethane (10 mmol, 0.8 mL) was added to the reaction mixture as an internal standard. 1 Analysis was performed by 1 H NMR. 1 1 H NMR measurement confirmed the formation of N-methyl-N-phenylcarbamic acid chloride in the solution after the reaction (NMR yield: >99%). The resulting reaction mixture was washed with an aqueous solvent, the resulting organic layer was dried over anhydrous sodium sulfate, and the solvent was removed by atmospheric distillation. The resulting residue was subjected to silica gel column chromatography (eluent: ethyl acetate / hexane = 5 / 1) and recrystallized using dichloromethane / hexane to obtain N-methyl-N-phenylcarbamic acid chloride as a white solid (yield: 88%, yield: 0.45 g, 2.7 mmol).

[0164] Example 15: Synthesis of α-amino acid N-carboxylic acid anhydrides (NCAs) [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (11.9 g, 83 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a flow rate of 388.9 μL / min to continuously generate chlorine gas. Dry air dehydrated through silica gel was then pumped into the flask at a flow rate of 55.5 mL / min (O2 flow rate: 0.49 mmol / min) using a mass flow controller, resulting in a chlorine-air mixture. The resulting mixture was then mixed with biogas at a flow rate of 24.8 mL / min (CH4 flow rate: 0.55 mmol / min). The resulting mixed gas was sent to a box-type photoreactor (volume: 891 mL) measuring 220 mm x 185 mm x 30 mm, where it was irradiated with light from a 365 nm LED lamp (45 W), yielding a photooxidized gas containing mainly carbonyl chloride and hydrogen chloride. The resulting photooxidation gas was blown into an acetonitrile solution (30 mL) containing L-phenylalanine (1 mmol, 0.17 g) and stirred at 70°C. The gas discharged from the reaction system was sent to an aqueous sodium bicarbonate solution to decompose and treat photooxidation products such as hydrogen chloride and excess carbonyl chloride. After 3 hours and 18 minutes of biogas injection (CH4 amount: 110 mmol) and 3 hours and 48 minutes of 365 nm light irradiation, the reaction system was stopped and air was introduced for 30 minutes to expel any remaining gas in the system. After the reaction was completed, 1,2-dichloroethane (10 mmol, 0.8 mL) was added to the reaction mixture as an internal standard. 1 Analysis was performed by 1 H NMR. 1 H NMR analysis confirmed the formation of L-phenylalanine-NCA in the reaction solution (NMR yield: >99%). 1M hydrochloric acid and dichloromethane were added to the resulting reaction solution, and the layers were separated. The organic layer was dried over anhydrous sodium sulfate, the solvent was removed by atmospheric distillation, and recrystallization from dichloromethane / hexane yielded L-phenylalanine-NCA as a yellow solid (yield: >99%, yield: 0.19 g, 1 mmol).

[0165] Example 16: Synthesis of polycarbonate [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (15.6 g, 109 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a flow rate of 388.9 μL / min to continuously generate chlorine gas. Dry air dehydrated through silica gel was then pumped into the flask at a flow rate of 55.5 mL / min (O2 flow rate: 0.49 mmol / min) using a mass flow controller, resulting in a chlorine-air mixture. The resulting mixture was then mixed with biogas at a flow rate of 24.8 mL / min (CH4 flow rate: 0.55 mmol / min). The resulting mixed gas was sent to a box-type photoreactor (volume: 891 mL) measuring 220 mm x 185 mm x 30 mm, where it was irradiated with light from a 365 nm LED lamp (45 W), yielding a photooxidized gas containing mainly carbonyl chloride and hydrogen chloride. The resulting photooxidation gas was blown into an acetonitrile solution (50 mL) containing bisphenol A (10 mmol, 2.28 g) and pyridine (200 mmol, 16.1 mL) and stirred at 30°C. The gas discharged from the reaction system was sent to an aqueous sodium bicarbonate solution to decompose and treat photooxidation products such as hydrogen chloride and excess carbonyl chloride. After 1 hour and 12 minutes of biogas injection (CH4 amount: 40 mmol) and 1 hour and 42 minutes of 365 nm light irradiation, the reaction system was stopped and air was blown into the system at 50 °C for 1 hour to expel any remaining gases in the system. After the reaction was completed, methanol was added to the reaction solution to precipitate the polymer, which was then filtered to obtain a white solid polycarbonate (yield: 88%, yield: 2.24 g, 8.8 mmol). The resulting polycarbonate bisphenol A was analyzed by gel permeation chromatography (GPC) to determine its molecular weight, and the results are shown in Table 9.

[0166] [Table 9]

[0167] Example 17: Synthesis of carboxylic acid chlorides [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (19.5 g, 136 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a rate of 388.9 μL / min to continuously generate chlorine gas. Dry air (40.0 mL / min, O2: 0.35 mmol / min) that had been dehydrated through silica gel was then pumped into the flask using a mass flow controller, producing a chlorine-air mixture. This mixture was then mixed with biogas (24.8 mL / min, CH4: 0.55 mmol / min). The resulting mixed gas was pumped into a 220 mm x 185 mm x 30 mm box-type photoreactor (volume: 891 mL) and irradiated with a 365 nm LED lamp (45 W). The resulting photooxidized gas was bubbled into a toluene solution (3.0 mL) containing 2-ethylhexanoic acid (40.5 mmol, 5.8 g) and DMF (40.5 mmol, 3.1 mL) and stirred at room temperature. The discharged gas was pumped into an aqueous sodium bicarbonate solution to decompose photooxidation products such as hydrogen chloride and excess carbonyl chloride. After 1.5 hours of biogas injection (CH4: 50 mmol) and 2 hours of 365 nm light irradiation, air was pumped in for 30 minutes to purge any remaining gas from the system. After the reaction was completed, 1,1,2,2-tetrachloroethane (10 mmol, 1.1 mL) was added to the solution as an internal standard. 1 The product was analyzed by H NMR. The results confirmed that the target product, 2-ethylhexanoyl chloride, was produced in a yield of 60% (24.3 mmol) based on the carboxylic acid used. It is believed that carbonyl chloride was produced from the methane contained in the biogas through an oxidative photoreaction, and that this carbonyl chloride reacted with DMF to produce Vilsmeier reagent, which then converted 2-ethylhexanoic acid into a chloride.

[0168] Example 18: Synthesis of Vilsmeier reagent and its dehydration reaction [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (7.2 g, 50 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a rate of 429 μL / min to continuously generate chlorine gas. Dry air (38.5 mL / min, O: 0.34 mmol / min) that had been dehydrated through silica gel was then pumped into the flask using a mass flow controller, producing a chlorine-air mixture. This mixture was then mixed with biogas (24.8 mL / min, CH: 0.55 mmol / min). The resulting mixed gas was pumped into a 220 mm x 185 mm x 30 mm box-type photoreactor (volume: 891 mL) and irradiated with a 365 nm LED lamp (45 W). The resulting photooxidized gas was bubbled into a chloroform solution (30 mL) containing benzamide (5 mmol, 0.61 g) and dimethylformamide (25 mmol, 1.83 g) and stirred at room temperature. The discharged gas was pumped into an aqueous sodium bicarbonate solution to decompose photooxidation products such as hydrogen chloride and excess carbonyl chloride. After 30 minutes of biogas injection (CH4: 0.55 mmol) and 1 hour of 365 nm light irradiation, air was pumped in for 30 minutes to purge any remaining gas from the system. After the reaction was completed, 1,1,2,2-tetrachloroethane (5 mmol, 0.53 mL) was added to the solution as an internal standard. 1 Analysis by H NMR confirmed that the target compound, benzonitrile, was produced in a yield of >99% based on the amide used. It is thought that the carbonyl chloride produced by the photoreaction reacted with DMF to produce a Vilsmeier reagent, which then contributed to the dehydration reaction of the carbamoyl group of the benzamide.

[0169] Example 19: Synthesis of carbonate [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (19.5 g, 136 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a rate of 388.9 μL / min to continuously generate chlorine gas. Dry air (40.0 mL / min, O2: 0.35 mmol / min) that had been dehydrated through silica gel was then pumped into the flask using a mass flow controller, producing a chlorine-air mixture. This mixture was then mixed with biogas (24.8 mL / min, CH4: 0.55 mmol / min). The resulting mixed gas was pumped into a 220 mm x 185 mm x 30 mm box-type photoreactor (volume: 891 mL) and irradiated with a 365 nm LED lamp (45 W). The resulting photooxidized gas was bubbled into a dichloromethane solution (10 mL) containing hexafluoro-2-propanol (40 mmol, 4.62 mL) and pyridine (160 mmol, 12.8 mL) and stirred at room temperature. The discharged gas was pumped into an aqueous sodium bicarbonate solution to decompose photooxidation products such as hydrogen chloride and excess carbonyl chloride. After 1.5 hours of biogas injection (CH4: 50 mmol) and 2 hours of 365 nm light irradiation, air was pumped in for 30 minutes to purge any remaining gas from the system. After the reaction was completed, 1,1,2,2-tetrachloroethane (10 mmol, 1.1 mL) was added to the solution as an internal standard. 1 Analysis by H NMR confirmed that the target compound, bis(1,1,1,3,3,3-hexafluoropropan-2-yl) carbonate, was produced in a yield of 98% (19.6 mmol) based on the alcohol used.

[0170] Example 20: Synthesis of isocyanates [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (19.5 g, 136 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a rate of 388.9 μL / min to continuously generate chlorine gas. Dry air (40.0 mL / min, O2: 0.35 mmol / min) that had been dehydrated through silica gel was then pumped into the flask using a mass flow controller, producing a chlorine-air mixture. This mixture was then mixed with biogas (24.8 mL / min, CH4: 0.55 mmol / min). The resulting mixed gas was pumped into a 220 mm x 185 mm x 30 mm box-type photoreactor (volume: 891 mL) and irradiated with a 365 nm LED lamp (45 W). The resulting photooxidized gas was blown into a toluene suspension (50 mL) of 2,6-dimethylaniline hydrochloride (5 mmol, 0.8 g) and stirred at 100 °C. The discharged gas was pumped into an aqueous sodium bicarbonate solution to decompose photooxidation products such as hydrogen chloride and excess carbonyl chloride. After 1.5 hours of biogas injection (CH4: 50 mmol) and 2 hours of 365 nm light irradiation, air was pumped in for 30 minutes to purge any remaining gas from the system. After the reaction was completed, 1,1,2,2-tetrachloroethane (5 mmol, 0.5 mL) was added to the reaction solution as an internal standard. 1 Analysis by H NMR confirmed that the target product, 2,6-dimethylphenyl isocyanate, was produced in a yield of 34% (1.7 mmol) based on the amount of 2,6-dimethylaniline hydrochloride used.

[0171] Example 21: Synthesis of isocyanates [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (19.5 g, 136 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a rate of 388.9 μL / min to continuously generate chlorine gas. Dry air (40.0 mL / min, O2: 0.35 mmol / min) that had been dehydrated through silica gel was then pumped into the flask using a mass flow controller, producing a chlorine-air mixture. This mixture was then mixed with biogas (24.8 mL / min, CH4: 0.55 mmol / min). The resulting mixed gas was transferred to a 220 mm x 185 mm x 30 mm box-type photoreactor (volume: 891 mL) and irradiated with a 365 nm LED lamp (45 W). The resulting photooxidized gas was then bubbled into toluene (200 mL) in a three-necked round-bottom flask and stirred at 0 °C. The discharged gas was then pumped into an aqueous solution of sodium bicarbonate to decompose photooxidation products such as hydrogen chloride and excess carbonyl chloride. After 1.5 hours of biogas injection (CH4: 50 mmol) and 2 hours of 365 nm light irradiation, a solution of 2,4-diaminotoluene (7 mmol, 0.9 g) dissolved in toluene (50 mL) was added to the three-necked round-bottom flask and stirred. A solution of pyridine (50 mmol, 4.0 g) dissolved in toluene (10 mL) was then added and stirred. The vessel was then heated to 70°C and air was pumped in for 30 minutes to expel any residual gas from the system. The reaction mixture was then washed with an aqueous solvent, the resulting organic layer was dried over anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. 1,2-Dichloroethane (5 mmol, 0.4 mL) was added to the resulting residue as an internal standard. 1 Analysis by H NMR confirmed that the target compound, tolylene-2,4-diisocyanate, was produced in a yield of 39% (2.0 mmol) based on the amount of 2,4-diaminotoluene used.

[0172] Example 22: Synthesis of carbonyl chloride from digester gas [ka] The reaction system shown in Figure 1 was used. Calcium hypochlorite (19.5 g, 136 mmol) was placed in a three-necked flask immersed in an ice bath. Chlorine gas was continuously generated by adding 2.1 mmol / L hydrochloric acid at a rate of 389 μL / min using a syringe pump at room temperature while irradiating the flask with 70 W, 42 kHz ultrasonic waves using an ultrasonic cleaner. Air delivered by an air pump and mass flow controller was dried through a silica gel-filled gas drying tube (16 mm inner diameter x 265 mm length) and then pumped into the three-neck flask at a flow rate of 32 mL / min (O2 flow rate: 0.28 mmol / min). The resulting chlorine-air mixture was combined with digester gas, the flow rate of which was controlled by a mass flow controller to 21.9 mL / min (methane flow rate: 0.55 mmol / min), and pumped into a PTFE coil heater. A chlorine-air-digestion gas mixture was prepared and pumped into the flow photoreactor. The digester gas was provided by a sewage treatment plant in City A and had a composition of methane: 59.2 vol%, carbon dioxide: 39.6 vol%, nitrogen: 0.3 vol%, oxygen: less than 0.2 vol%, water: 1.2 vol%, other gases: less than 0.1 vol%, and hydrogen sulfide: less than 0.01 vol ppm. The flow photoreactor is 220mm x 185mm x 30mm, plate thickness: 3.3mm, and internal volume: 891cm 3 and a 365 nm LED lamp (Polarstar, peak wavelength: 365 nm, 45 W, LED size: 14 cm × 18 cm, illuminance: 54.7–54.4 mW / cm). 2 ) The residence time of the reaction gas in the flow photoreactor was 10.4 minutes. During the reaction, the temperature was not controlled by the flow photoreactor or the coil heater. The gaseous products generated from the flow photoreactor were blown into 1-butanol placed in the first reactor, and the gas from the first reactor was supplied to a second reactor, which also contained 1-butanol. After 1 hour and 30 minutes of digestion gas injection (CH4: 49 mmol) and 2 hours of 365 nm light irradiation, air was pumped in for 30 minutes to expel residual gas from the system. The reaction solutions in the first and second reactors were 1 The amount of carbonyl chloride produced was determined from the amounts of ethyl chloroformate and dibutyl carbonate produced by H NMR analysis. The results are shown in Table 10.

[0173] [Table 10]

[0174] As shown in Table 10, the results demonstrate that the method of the present invention can successfully produce carbonyl chloride from biogas obtained from a sewage treatment plant.

[0175] Example 23: Synthesis of isocyanate from digester gas [ka] The reaction system shown in Figure 1 was used. A three-necked round-bottom flask containing calcium hypochlorite (19.5 g, 136 mmol) was placed in an ultrasonic generator. Under ultrasonic irradiation, 35% hydrochloric acid was injected using a syringe pump at a rate of 388.9 μL / min to continuously generate chlorine gas. Dry air (32.0 mL / min, O2: 0.28 mmol / min) dehydrated through silica gel was then pumped into the flask using a mass flow controller to generate a chlorine-air mixture. This mixture was then mixed with digester gas (21.9 mL / min, CH4: 0.54 mmol / min). The digester gas was provided by a sewage treatment plant in City A and had a composition of methane: 59.2 vol%, carbon dioxide: 39.6 vol%, nitrogen: 0.3 vol%, oxygen: less than 0.2 vol%, water: 1.2 vol%, other gases: less than 0.1 vol%, and hydrogen sulfide: less than 0.01 vol ppm. The resulting mixed gas was transferred to a 220 mm x 185 mm x 30 mm box-type photoreactor (volume: 891 mL) and irradiated with a 365 nm LED lamp (45 W). The resulting photooxidized gas was then bubbled into toluene (200 mL) in a three-necked round-bottom flask and stirred at 0 °C. The discharged gas was then pumped into an aqueous sodium bicarbonate solution to decompose photooxidation products such as hydrogen chloride and excess carbonyl chloride. After 1.5 hours of biogas injection (CH4: 49 mmol) and 2 hours of 365 nm light irradiation, a solution of 2,4-diaminotoluene (5 mmol, 0.6 g) in toluene (50 mL) was added to the three-necked round-bottom flask and stirred. A solution of pyridine (50 mmol, 4.0 g) in toluene (10 mL) was then added and stirred. The vessel was then heated to 70°C and air was pumped in for 30 minutes to expel any residual gas from the system. The reaction mixture was then washed with an aqueous solvent, the resulting organic layer was dried over anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. 1,2-Dichloroethane (5 mmol, 0.4 mL) was added to the resulting residue as an internal standard. 1 Analysis by H NMR confirmed that the target compound, tolylene-2,4-diisocyanate, was produced in a yield of 43% (2.2 mmol, 0.37 g) based on the amount of 2,4-diaminotoluene used. [Explanation of symbols]

[0176] 1: Silica gel drying tube, 2: Mass flow controller 3: Halogen gas generator, 4: Calcium chloride drying tube 5: Methane gas cylinder, 6: Coil heater, 7: Photoreactor 8: Heater, 9: Light source, 10: Reaction vessel

Claims

1. 1. A process for producing a carbonyl halide, comprising: A method comprising the step of irradiating a mixed gas containing methane, a halogen element gas, and oxygen with light having a peak wavelength in the range of 180 nm to 500 nm.

2. 2. The method according to claim 1, wherein the carbonyl halide is carbonyl chloride and the halogen element gas is chlorine gas.

3. The method of claim 1 , wherein the light has a peak wavelength of at least 360 nm and at most 500 nm.

4. The method according to claim 1 , wherein the mixed gas is irradiated with the light at room temperature.

5. 2. The method according to claim 1, wherein the shortest distance between the light source for irradiating the light and the mixed gas is 1 m or less.

6. 2. The method according to claim 1, further comprising the step of neutralizing hydrogen halide produced as a by-product by irradiating the mixed gas with light with a basic sodium salt to obtain an aqueous sodium halide solution.

7. 2. The method according to claim 1, further comprising the step of obtaining the halogen element gas and sodium hydroxide by electrolysis of an aqueous sodium halide solution.

8. 1. A method for producing a carbonate compound, comprising: Producing a carbonyl halide by the method according to any one of claims 1 to 7; and A method comprising the step of reacting an alcohol compound with the carbonyl halide.

9. 1. A method for producing a halogenated formate compound, comprising: Producing a carbonyl halide by the method according to any one of claims 1 to 7; and A method comprising the step of reacting an alcohol compound with the carbonyl halide.

10. A method for producing an isocyanate compound, comprising: Producing a carbonyl halide by the method according to any one of claims 1 to 7; and A method comprising the step of reacting a primary amine compound with the carbonyl halide.

11. 1. A process for producing a carbamoyl halide compound, comprising: Producing a carbonyl halide by the method according to any one of claims 1 to 7; and A method comprising the step of reacting a secondary amine compound with the carbonyl halide.

12. 1. A method for producing an amino acid-N-carboxylic acid anhydride, comprising: The amino acid N-carboxylic acid anhydride is represented by the following formula (VIII): Producing a carbonyl halide by the method according to any one of claims 1 to 7; and A method comprising the step of reacting an amino acid compound represented by the following formula (VII) with the carbonyl halide: 【Chemical 1】 [In the formula, R 4 represents an amino acid side chain group in which a reactive group is protected, R 5 is H or P 1 -[-NH-CHR 6 -C(=O)-] l - (wherein, R 6 indicates an amino acid side chain in which the reactive group is protected, and P 1 represents a protecting group for an 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 or different).

13. 1. A method for producing a Vilsmeier reagent, comprising: The Vilsmeier reagent is a salt represented by the following formula (X): 【Chemistry 2】 [In the formula, R 7 is a hydrogen atom, C 1-6 an alkyl group or a C group which may have a substituent 6-12 represents an aromatic hydrocarbon group, R 8 and R 9 are independently 1-6 an alkyl group or a C group which may have a substituent 6-12 represents an aromatic hydrocarbon group, and R 8 and R 9 may be joined together to form a 4- to 7-membered ring structure, X represents a halogeno group selected from the group consisting of chloro, bromo and iodo; Y - indicates a counter anion.] Producing a carbonyl halide by the method according to any one of claims 1 to 7; and The method comprises a step of reacting the carbonyl halide with an amide compound represented by the following formula (IX): 【Chemistry 3】 [In the formula, R 7 ~R 9 has the same meaning as above.]

14. 1. A method for producing a urea compound, comprising: Producing a carbonyl halide by the method according to any one of claims 1 to 7; and A method comprising the step of reacting a primary amine compound or a secondary amine compound with the carbonyl halide.

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