Process for the preparation of sphingomyelins

Abstract

An object of the present invention is to provide a method for easily producing sphingomyelins.SOLUTION: A phosphocholine-forming agent represented by general formula (1) is reacted with ceramides represented by general formula (2). According to the present invention, sphingomyelins represented by the following general formula (3) can be produced by a one step reaction. (In the formula, A represents a five membered nitrogen-containing heterocyclic structure, and Ra and Rb each independently represent a saturated or unsaturated hydrocarbon group which may be substituted.). ) SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing sphingomyelins. [Background technology]

[0002] Sphingomyelins are compounds in which a phosphocholine group is bound to the primary hydroxyl group of ceramides, which are compounds in which a fatty acid is amide-bonded to the amino group of a sphingoid base. Sphingomyelins exist in living organisms and play an important role in vital activities. They are also used as active ingredients and components of lipid particles in the fields of pharmaceuticals and topical skin preparations (e.g., Patent Documents 1 to 4).

[0003] To produce sphingomyelins, it is necessary to introduce a phosphocholine group into a primary hydroxyl group of a ceramide via a phosphate ester bond. Common methods for introducing a phosphocholine group into a ceramide include reacting the primary hydroxyl group of a ceramide with 2-chloro-2-oxo-1,3,2-dioxaphosphorane to form a cyclic phosphate ester, which is then ring-opened with trimethylamine (Patent Document 5); reacting the primary hydroxyl group of a ceramide with 2-chloro-1,3,2-dioxaphosphorane to form a cyclic phosphate ester, which is then ring-opened by reaction with bromine, and then reacting the ring-opened product with trimethylamine and water; and converting the primary hydroxyl group of a ceramide into a phosphoramidite, which is then reacted with choline and subsequently oxidized (Non-Patent Document 1). However, all of these conventional methods require multiple reaction steps using ceramides as a starting material, making them complicated. Therefore, a simpler method for producing sphingomyelins is desired. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 97 / 30696 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-151818 [Patent Document 3] Special Publication No. 2007-507492 [Patent Document 4] International Publication No. 2007 / 145276 [Patent Document 5] U.S. Patent Application Publication No. 2014 / 0275590 [Non-patent literature]

[0005] [Non-Patent Document 1] Robert Bittman,Synthesis of Sphingomyelin and Ceramide 1-Phosphate from Ceramide without Protection of the Allylic Hydroxyl Group,J.Org.Chem.,1994,59,6495-6498. Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a method for simply producing sphingomyelins. [Means for solving the problem]

[0007] As a result of intensive research to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by a method for producing sphingomyelins represented by the following general formula (3), which is characterized by reacting a phosphocholinating agent represented by the following general formula (1) with a ceramide represented by the following general formula (2), and have completed the present invention. [ka] (In general formula (1), A is selected from the following structural formulas (i) to (x).) [ka] (In the structural formulas (i) to (x), R1, R2, R3, R4, R5, R6, R7, and R8 each independently represent an alkyl group having 1 to 12 carbon atoms; R9 and R 10 each independently represents an alkyl group, alkenyl group, or alkynyl group having 1 to 22 carbon atoms, and * indicates a bond.) [ka] (In general formula (2), R a and R b each independently represents an optionally substituted saturated or unsaturated hydrocarbon group. [ka] (In general formula (3), R a and R b is the same as the general formula (2). [Effects of the Invention]

[0008] According to the production method of the present invention, a phosphocholine group can be introduced into the primary hydroxyl group of a ceramide in a single-step reaction, and therefore, sphingomyelins can be produced simply and easily. DETAILED DESCRIPTION OF THE INVENTION

[0009] The method for producing sphingomyelins of the present invention is characterized by reacting a phosphocholinating agent described below with a ceramide described below.

[0010] <About phosphocholinating agents> The phosphocholinating agent used in the present invention is a compound represented by the following general formula (1). [ka] (In general formula (1), A is selected from the following structural formulas (i) to (x).) [ka] (In the structural formulas (i) to (x), R1, R2, R3, R4, R5, R6, R7, and R8 each independently represent an alkyl group having 1 to 12 carbon atoms; R9 and R 10 each independently represents an alkyl group, alkenyl group, or alkynyl group having 1 to 22 carbon atoms, and * indicates a bond.)

[0011] The phosphocholinating agent represented by general formula (1) used in the present invention is a compound having a structure in which the phosphorus atom of phosphocholine and the nitrogen atom of a nitrogen-containing heterocyclic compound are covalently bonded. A in general formula (1) is selected from the above structural formulas (i) to (x), which have in common the fact that they are five-membered rings and that the only heteroatom forming the ring is a nitrogen atom, in addition to having a nitrogen-containing heterocyclic structure. From the viewpoint of further exerting the effects of the present invention, A in general formula (1) is preferably selected from structural formulas (i), (ii), (iii), (iv), (vi), (viii), and (ix), and more preferably selected from structural formulas (i), (ii), and (vi). R1, R2, R3, R4, R5, R6, R7, and R8 in the structural formula of A are preferably alkyl groups having 1 to 8 carbon atoms, more preferably alkyl groups having 1 to 6 carbon atoms. Furthermore, R9 and R 10 is preferably an alkyl group, alkenyl group or alkynyl group having 1 to 12 carbon atoms, and more preferably an alkyl group having 1 to 12 carbon atoms.

[0012] There is no particular limitation on the method for producing the phosphocholinating agent represented by general formula (1), and it may be produced by a generally known method. However, from the viewpoint of more efficient production, it is preferable to produce it by reacting a compound represented by the following general formula (I) with a compound represented by the following general formula (II). [ka] [ka] (In the formula, A has the same meaning as A in the general formula (1) above.) [ka]

[0013] The compound represented by the general formula (I) is generally known as phosphocholine. The compound represented by the general formula (I) may be in the form of a salt. Compounds represented by the general formula (I) are generally commercially available, and such commercially available products can be used. Commercially available compounds are generally aqueous solutions or hydrates, but from the standpoint of yield and economic efficiency, it is preferable to use dehydrated compounds. Examples of dehydration methods include azeotropy with an organic solvent capable of azeotroping with water, or reaction with a dehydrating agent in the presence of an acid catalyst. The organic solvent capable of azeotroping with water is not particularly limited, but toluene and methoxyethanol can be used. The dehydrating agent is not particularly limited, but orthoesters can be used. It is more preferable to use a compound that has been dehydrated by the above method and then powdered by recrystallization or pulverization.

[0014] The compound represented by the general formula (II) is a carbonyl compound having two nitrogen-containing heterocycles. The two A structures in the compound represented by the general formula (II) may be the same or different, but are preferably the same. The compound represented by the general formula (II) may be in the form of a salt. The compound represented by the general formula (II) can be a commercially available product, or can be obtained by a commonly known production method, for example, by reacting a nitrogen-containing heterocycle having the structural formula A (a compound in which the bond in the structural formula A is bonded to a hydrogen atom) with phosgene.

[0015] In the production of the phosphocholinating agent of general formula (1), the reaction ratio of the compound represented by general formula (I) to the compound represented by general formula (II) is preferably 1 to 10 moles, preferably 1.5 to 8 moles, more preferably 2 to 6 moles, of the compound represented by general formula (II) per 1 mole of the compound represented by general formula (I), from the viewpoints of yield and economy.

[0016] In the production of the phosphocholinating agent of general formula (1), the reaction can be carried out in the presence of a base in order to further promote the progress of the reaction. Specific examples of the base used include organic bases such as trimethylamine, triethylamine, tripropylamine, tributylamine, diisopropylethylamine, tetramethylguanidine, imidazole, N-methylimidazole, triazole, tetrazole, pyridine, dimethylaminopyridine, picoline, lutidine, collidine, piperidine, dimethylpiperidine, N-methylmorpholine, N,N-dimethylaniline, quinoline, diazabicycloundecene, diazabicyclononene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, and 1,4-diazabicyclo[2.2.2]octane; and inorganic bases such as sodium hydroxide, potassium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, sodium t-butoxide, and potassium t-butoxide. These bases may be used alone or in combination. Among these, organic bases are preferred, and among organic bases, triethylamine, tripropylamine, tributylamine, diisopropylethylamine, and pyridine are more preferred, with triethylamine and pyridine being even more preferred. The amount of base used is preferably 0.1 moles or more, and preferably 0.5 moles or more, per mole of the compound represented by general formula (II). There is no particular upper limit to the amount used, but from the viewpoint of economy, it is generally preferred to use a ratio of 10 moles or less, and preferably 5 moles or less.

[0017] In the production of the phosphocholinating agent of general formula (1), the reaction can be carried out in the presence of a solvent to further promote the reaction. The solvent used is not particularly limited as long as it can dissolve or disperse the compound represented by general formula (I) and the compound represented by general formula (II). Specific examples include dichloromethane, chloroform, dimethyl sulfoxide, sulfolane, dimethylformamide, N-methylpyrrolidone, dimethylacetamide, dimethylimidazolidinone, cyclohexanone, γ-butyrolactone, dihydrolevoglucosenone, monoglyme, and diglyme. These may be used alone or in combination. Among these, dimethyl sulfoxide, dimethylformamide, N-methylpyrrolidone, dimethylacetamide, and dihydrolevoglucosenone are preferred, with dimethyl sulfoxide and dimethylformamide being more preferred. Furthermore, among the above-mentioned organic bases, those that are liquid at the reaction temperature can also be used as the solvent. The amount of the solvent used is not particularly limited, but is usually 0.2 times by mass or more, preferably 0.5 times by mass or more, based on the total mass of the compound represented by general formula (I) and the compound represented by general formula (II). The upper limit of the amount used is not particularly limited, but from the viewpoint of economy, it is generally 10 times by mass or less, preferably 5 times by mass or less.

[0018] In order to allow the reaction to proceed more efficiently, the reaction temperature in the production of the phosphocholinating agent of general formula (1) is usually 0 to 100° C., preferably 5 to 90° C., and more preferably 10 to 80° C. The reaction time is not particularly limited, but is usually 2 to 72 hours, preferably 4 to 60 hours, and more preferably 6 to 48 hours.

[0019] The phosphocholinating agent of general formula (1) produced by the above method may be used for the intended purpose as it is, or may be purified by a purification method commonly used in the art, such as extraction, deacidification, washing with water, recrystallization, reprecipitation, cleaning, filtration, distillation, various column chromatography methods, etc.

[0020] <About ceramides> The ceramides used in the present invention are compounds represented by the following general formula (2). [ka] (In general formula (2), R a and R b each independently represents an optionally substituted saturated or unsaturated hydrocarbon group.

[0021] R of the ceramides of general formula (2) used in the present invention a Specifically, R represents a linear or branched, saturated or unsaturated hydrocarbon group having 1 to 27 carbon atoms, and the hydrocarbon group may be substituted with an atom selected from oxygen, nitrogen, chlorine, fluorine, bromine, iodine, boron, silicon, sulfur, and phosphorus. a The number of carbon atoms is preferably 5 to 21, and more preferably 9 to 19.

[0022] R of the ceramides of general formula (2) used in the present invention a is more preferably selected from the following structural formulas (a) to (d). [ka] (In the above structural formulas (a) to (d), p is an integer of 0 to 26, q is an integer of 0 to 25, r is an integer of 0 to 24, s is an integer of 0 to 23, and * represents a bond.)

[0023] In the structural formula (a), p is preferably 4-20, and more preferably 8-18.

[0024] In the structural formula (b), q is preferably 3-19, and more preferably 7-17.

[0025] In the structural formula (c), r is preferably 2-18, and more preferably 6-16.

[0026] In the structural formula (d), s is preferably 1-17, and more preferably 5-15.

[0027] R of the ceramides of general formula (2) used in the present invention b Specifically, R represents a linear or branched, saturated or unsaturated hydrocarbon group having 1 to 59 carbon atoms, and the hydrocarbon group may be substituted with an atom selected from oxygen, nitrogen, chlorine, fluorine, bromine, iodine, boron, silicon, sulfur, and phosphorus. b The number of carbon atoms is preferably 7 to 47, and more preferably 11 to 43.

[0028] R of the ceramides of general formula (2) used in the present invention b is more preferably selected from the following structural formulas (e) to (g). [ka] (In the above structural formulas (e) to (g), n is an integer of 0 to 28, m is an integer of 0 to 27, k is an integer of 0 to 28, and R c represents an optionally substituted saturated or unsaturated hydrocarbon group having 1 to 29 carbon atoms, and * represents a bond.

[0029] In the structural formula (e), n is preferably 6-22, and more preferably 10-20.

[0030] In the structural formula (f), m is preferably 5-21, and more preferably 9-19.

[0031] In the structural formula (g), k is preferably 6-22, and more preferably 10-20.

[0032] R in the above structural formula (g) c is preferably a linear or branched, saturated or unsaturated hydrocarbon group having 7 to 23 carbon atoms, more preferably 11 to 21 carbon atoms. Cmay be substituted with an atom selected from oxygen, nitrogen, chlorine, fluorine, bromine, iodine, boron, silicon, sulfur, and phosphorus.

[0033] In the above general formula (2), R a is the structural formula of (b), and R b When the structural formula is (g), it is a compound commonly called ceramide 1 (EOP).

[0034] In the above general formula (2), R a is the structural formula of (c), and R b When the structural formula is (e), it is a compound generally called ceramide 2 (NS).

[0035] In the above general formula (2), R a is the structural formula of (b), and R b When the structural formula is (e), it is a compound generally called ceramide 3 (NP).

[0036] In the above general formula (2), R a is the structural formula of (d), and R b When the structural formula is (g), it is a compound generally called ceramide 4(EOH).

[0037] In the above general formula (2), R a is the structural formula of (c), and R b When the structural formula is (f), it is a compound generally called ceramide 5 (AS).

[0038] In the above general formula (2), R a is the structural formula of (b), and R b When the structural formula is (f), it is a compound generally called ceramide 6 (AP).

[0039] In the above general formula (2), R a is the structural formula of (d), and R b When the structural formula is (f), it is a compound commonly called ceramide 7 (AH).

[0040] In the above general formula (2), R a is the structural formula of (d), and R b When the structural formula is (e), it is a compound generally called ceramide 8(NH).

[0041] In the above general formula (2), R a is the structural formula of (c), and R b When the structural formula is (g), it is a compound commonly called ceramide 9 (EOS).

[0042] In the above general formula (2), R a is the structural formula of (a), and R b When the structural formula is (e), it is a compound generally called ceramide 10 (NDS).

[0043] The ceramides represented by the general formula (2) can be produced by a generally known method. In addition, the ceramides represented by the general formula (2) are generally commercially available, and such commercially available products can be used.

[0044] <Method of producing sphingomyelins> The method for producing sphingomyelins of the present invention is characterized by reacting a phosphocholinating agent represented by the above-mentioned general formula (1) with a ceramide represented by the above-mentioned general formula (2). The sphingomyelins produced by the production method of the present invention are compounds represented by the following general formula (3). [ka] (In general formula (3), R a and R b is the same as the general formula (2).

[0045] The method for producing sphingomyelins of the present invention is shown in the following reaction scheme. [ka]

[0046] In the method for producing sphingomyelins of the present invention, the reaction ratio between the phosphocholinating agent represented by general formula (1) and the ceramides represented by general formula (2) is not particularly limited. However, from the viewpoints of yield and economy, the phosphocholinating agent is reacted in a ratio of 1 to 10 moles, preferably 1.1 to 7.5 moles, more preferably 1.2 to 5 moles, per mole of ceramides.

[0047] In the method for producing sphingomyelins of the present invention, the reaction between the phosphocholinating agent represented by general formula (1) and the ceramide represented by general formula (2) can be carried out in the absence of a solvent or in the presence of a solvent. The solvent used is not particularly limited as long as it can dissolve or disperse the phosphocholinating agent and the ceramide. Specific examples include organic solvents such as ethyl acetate, propyl acetate, butyl acetate, pentyl acetate, chloroform, carbon tetrachloride, dichloroethane, chlorobenzene, benzene, toluene, xylene, heptane, methylcyclohexane, acetonitrile, dimethyl sulfoxide, sulfolane, dimethylformamide, N-methylpyrrolidone, dimethylacetamide, dimethylimidazolidinone, pyridine, triethylamine, tetrahydrofuran, methyltetrahydrofuran, tetrahydropyran, methyltetrahydropyran, dioxane, cyclopentyl methyl ether, monoglyme, and diglyme. These solvents may be used alone or in combination. Of these, benzene, toluene, xylene, heptane, methylcyclohexane, methyltetrahydrofuran, methyltetrahydropyran, dioxane, and cyclopentyl methyl ether are preferred, and toluene, xylene, methylcyclohexane, and cyclopentyl methyl ether are more preferred.

[0048] The amount of the solvent used is not particularly limited, but is preferably 0.2 times or more, and preferably 0.5 times or more, by mass relative to the total mass of the phosphocholinating agent and ceramides. The upper limit of the amount used is not particularly limited, but from an economical standpoint, it is generally 10 times or less, and preferably 5 times or less.

[0049] In the method for producing sphingomyelins of the present invention, the reaction temperature between the phosphocholinating agent represented by general formula (1) and the ceramide represented by general formula (2) is not particularly limited, but from the viewpoint of more efficient reaction progression, it is usually 40 to 180° C., preferably 60 to 140° C., and more preferably 80 to 120° C. The reaction time is not particularly limited, but it is usually 2 to 72 hours, preferably 4 to 60 hours, and more preferably 6 to 48 hours.

[0050] In the method for producing sphingomyelins of the present invention, an iron catalyst is preferably used as the catalyst from the viewpoint of improving the yield. Specific examples of iron catalysts include iron halides such as iron fluoride, iron chloride, iron bromide, and iron iodide, and iron acetate. These may be used alone or in combination of two or more. Of these, iron chloride, iron bromide, and iron acetate are preferred, as they allow the target sphingomyelins to be obtained in high yield and are easy to handle, and iron chloride is most preferred.

[0051] The amount of the iron catalyst used is not particularly limited, but from the viewpoint of improving the yield, it is advisable to use 0.001 mol or more, preferably 0.005 mol or more, more preferably 0.01 mol or more per mol of ceramides. The upper limit of the amount used is not particularly limited, but from the viewpoint of economic efficiency, it is preferably 1 mol or less, more preferably 0.5 mol or less, and even more preferably 0.1 mol or less.

[0052] The above-described production method allows for the introduction of a phosphocholine group into the primary hydroxyl group of a ceramide in a single reaction step, thereby enabling the convenient production of sphingomyelins. The sphingomyelins thus obtained can be purified by purification methods commonly used in the art, such as extraction, washing with water, recrystallization, reprecipitation, cleaning, filtration, and various column chromatography methods.

[0053] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.1 H NMR measurements were performed using a JNM-AL300 manufactured by JEOL Datum Co., Ltd., and mass spectrometry was performed using a SCIEX QTRAP4500 manufactured by AB Sciex Corporation.

[0054] In the following synthesis examples and working examples, the compounds synthesized or used are represented as follows: In the case of a phosphocholinating agent represented by general formula (1), when A is the structural formula (i), the compound is represented as (1-i). In the case of a ceramide represented by general formula (2), when R a is the structural formula of (a), and p is 14, and R b When the structural formula is (e) and n is 16, the compound is represented as (2-a14-e16). In the sphingomyelins represented by the general formula (3), R a is the structural formula of (a), and p is 14, and R b If has the structural formula (e) and n is 16, the compound is written as (3-a14-e16).

[0055] Synthesis Example 1: Synthesis of phosphocholinating agent (1-i) [ka] Under a nitrogen atmosphere, 15.7 g of phosphocholine was placed in a reaction vessel, followed by 95 mL of dimethylformamide as a solvent and stirring. Next, 55.6 g of 1,1'-carbonylbis-1H-imidazole was added, followed by dropwise addition of 35.1 g of triethylamine as a base. After dropwise addition, the mixture was reacted at 25°C for 24 hours, then cooled to 5°C, and ethanol was added dropwise and stirred for 30 minutes. The resulting reaction solution was concentrated under reduced pressure at 50°C, and acetone was added to precipitate a solid. After cooling to 5°C, the solid was collected by suction filtration. The resulting solid was dried under reduced pressure to obtain the desired phosphocholineating agent (1-i). 1 H NMR (300MHz, solvent CD3OD): δ=7.90(s,1H),7.30(d,J=1.2Hz,1H),7.05(m,1H),4.20-4.18(m,2H),3.60-3.57(m,2H),3.17(s,9H) Mass spectrometry (ESI): m / z=234[M+H] +

[0056] Synthesis Example 2: Synthesis of phosphocholinating agent (1-ii) [ka] Under a nitrogen atmosphere, 2.6 g of phosphocholine was placed in a reaction vessel, followed by 15 mL of dimethylformamide as a solvent and stirring. Next, 8.9 g of 3,3'-dimethyl-1,1'-carbonylbis-1H-imidazole methyl sulfate was added, followed by dropwise addition of 6.7 g of triethylamine as a base. After the dropwise addition, the mixture was reacted at 25°C for 15 hours, cooled to 5°C, and ethanol was added dropwise and stirred for 30 minutes. The resulting reaction solution was concentrated under reduced pressure at 50°C, and acetone was added to precipitate a solid. After cooling to 5°C, the solid was collected by suction filtration. The resulting solid was dried under reduced pressure to obtain the desired phosphocholineating agent (1-ii). 1 H NMR (300MHz, solvent DMSO-d6): δ=8.83(s,1H),7.56(m,2H),4.25(m,2H),3.84(s,6H),3.75(s,3H),3.58-3.55(m,2H),3.15(s,9H) Mass spectrometry (ESI): m / z=248[M+H] +

[0057] Synthesis Example 3: Synthesis of phosphocholinating agent (1-vi) [ka] Under a nitrogen atmosphere, 4.0 g of phosphocholine was placed in a reaction vessel, followed by 20 mL of dimethylformamide as a solvent and stirring. Next, 10.7 g of 1,1'-carbonyldi(1,2,4-triazole) was added, followed by dropwise addition of 6.7 g of triethylamine as a base. After dropwise addition, the mixture was reacted at 25°C for 36 hours, then cooled to 5°C, and ethanol was added dropwise and stirred for 30 minutes. The resulting reaction solution was concentrated under reduced pressure at 50°C, and acetone was added to precipitate a solid. After cooling to 5°C, the solid was collected by suction filtration. The resulting solid was dried under reduced pressure to obtain the desired phosphocholineating agent (1-vi). 1 H NMR (300MHz, solvent DMSO-d6): δ=8.47(s,1H),8.00(s,1H),4.17-4.11(m,2H),3.55-3.52(m,2H),3.08(s,9H) Mass spectrometry (ESI): m / z=235[M+H] +

[0058] Example 1 Synthesis of sphingomyelins (3-a14-e16) (1) [ka] 1.2 g of ceramides (2-a14-e16) and 0.5 g of phosphocholinating agent (1-i) were mixed and reacted with stirring for 16 hours at 120° C. The resulting reaction solution was purified by silica gel column chromatography (elution solvent: a mixture of chloroform / methanol / water) to obtain the desired sphingomyelins (3-a14-e16) (0.26 g, 17% yield). 1 H NMR (300 MHz, solvent: CDCl3:CD3OD = 20:1): δ = 4.25-4.22 (m, 3H), 3.86-3.83 (m, 2H), 3.64-3.57 (m, 3H), 3.24 (s, 9H), 2.19 (t, J = 7.5 Hz, 2H), 1.60-1.53 ​​(m, 4H), 1.25 (m, 54H), 0.88 (t, J = 6.5 Hz, 6H). OH and NH are lost due to HD exchange. Mass spectrometry (ESI): m / z=734[M+H] +

[0059] Example 2 Synthesis of sphingomyelins (3-a14-e16) (2) [ka] The synthesis was carried out in the same manner as in Example 1, except that phosphocholinating agent (1-ii) was used instead of phosphocholinating agent (1-i) in Example 1, and the desired sphingomyelins (3-a14-e16) were obtained (0.25 g, yield 16%). 1 H NMR (300 MHz, solvent: CDCl3:CD3OD = 20:1): δ = 4.25-4.22 (m, 3H), 3.86-3.83 (m, 2H), 3.64-3.57 (m, 3H), 3.24 (s, 9H), 2.19 (t, J = 7.5 Hz, 2H), 1.60-1.53 ​​(m, 4H), 1.25 (m, 54H), 0.88 (t, J = 6.5 Hz, 6H). OH and NH are lost due to HD exchange. Mass spectrometry (ESI): m / z=734[M+H] +

[0060] Example 3 Synthesis of sphingomyelins (3-a14-e16) (3) [ka] The synthesis was carried out in the same manner as in Example 1, except that phosphocholinating agent (1-vi) was used instead of phosphocholinating agent (1-i) in Example 1, and the desired sphingomyelins (3-a14-e16) were obtained (0.25 g, yield 16%). 1H NMR (300 MHz, solvent: CDCl3:CD3OD = 20:1): δ = 4.25-4.22 (m, 3H), 3.86-3.83 (m, 2H), 3.64-3.57 (m, 3H), 3.24 (s, 9H), 2.19 (t, J = 7.5 Hz, 2H), 1.60-1.53 ​​(m, 4H), 1.25 (m, 54H), 0.88 (t, J = 6.5 Hz, 6H). OH and NH are lost due to HD exchange. Mass spectrometry (ESI): m / z=734[M+H] +

[0061] Example 4 Synthesis of sphingomyelins (3-a14-e16) (4) [ka] 1.2 g of ceramides (2-a14-e16) and 1.0 g of phosphocholinating agent (1-i) were suspended in 3.0 g of xylene, heated to 120°C with stirring, and then reacted for 18 hours. The resulting reaction solution was cooled to 40°C, and acetone was added and suspended. The solid was filtered from the resulting suspension. The resulting solid was purified by silica gel column chromatography (elution solvent: chloroform / methanol / water mixture) to obtain the desired sphingomyelins (3-a14-e16) (0.26 g, 17% yield). 1 H NMR (300 MHz, solvent: CDCl3:CD3OD = 20:1): δ = 4.25-4.22 (m, 3H), 3.86-3.83 (m, 2H), 3.64-3.57 (m, 3H), 3.24 (s, 9H), 2.19 (t, J = 7.5 Hz, 2H), 1.60-1.53 ​​(m, 4H), 1.25 (m, 54H), 0.88 (t, J = 6.5 Hz, 6H). OH and NH are lost due to HD exchange. Mass spectrometry (ESI): m / z=734[M+H] +

[0062] Example 5 Synthesis of sphingomyelins (3-a14-e16) (5) [ka] 1.2 g of ceramides (2-a14-e16), 1.0 g of phosphocholinating agent (1-i), and 3 mg of iron(II) chloride were suspended in 3.0 g of xylene, heated to 120°C with stirring, and then reacted for 18 hours. The resulting reaction solution was cooled to 40°C, and acetone was added and suspended. The solid was filtered from the resulting suspension. The resulting solid was purified by silica gel column chromatography (elution solvent: a mixture of chloroform / methanol / water) to obtain the desired sphingomyelins (3-a14-e16) (0.79 g, 50% yield). 1 H NMR (300 MHz, solvent: CDCl3:CD3OD = 20:1): δ = 4.25-4.22 (m, 3H), 3.86-3.83 (m, 2H), 3.64-3.57 (m, 3H), 3.24 (s, 9H), 2.19 (t, J = 7.5 Hz, 2H), 1.60-1.53 ​​(m, 4H), 1.25 (m, 54H), 0.88 (t, J = 6.5 Hz, 6H). OH and NH are lost due to HD exchange. Mass spectrometry (ESI): m / z=734[M+H] +

[0063] Example 6 Synthesis of sphingomyelins (3-a14-e16) (6) [ka] 14.6 g of ceramides (2-a14-e16), 12.0 g of phosphocholinating agent (1-i), and 163 mg of iron(II) chloride were suspended in 58.4 g of cyclopentyl methyl ether, heated to 100°C with stirring, and then reacted for 24 hours. The resulting reaction solution was extracted with cyclopentyl methyl ether, methanol, and 0.5 M hydrochloric acid. The resulting organic solvent layer was washed with a 0.5 M hydrochloric acid / methanol mixture. Methanol was evaporated from the resulting organic solvent layer, and acetone was added to the concentrated solution to precipitate a solid. The precipitated solid was filtered off to obtain a crude product. The resulting crude product was dissolved in a toluene / methanol mixture at 40°C, followed by the addition of an ion exchange resin (Diaion SMNUPB, manufactured by Mitsubishi Chemical Corporation) and stirring. The ion exchange resin was removed by filtration, and methanol was evaporated from the resulting solution. Acetone was added to the concentrated solution to precipitate a solid. The precipitated solid was filtered off and dried in vacuo to obtain the desired sphingomyelin (3-a14-e16) (12.0 g, yield 64%). 1 H NMR (300 MHz, solvent: CDCl3:CD3OD = 20:1): δ = 4.25-4.22 (m, 3H), 3.86-3.83 (m, 2H), 3.64-3.57 (m, 3H), 3.24 (s, 9H), 2.19 (t, J = 7.5 Hz, 2H), 1.60-1.53 ​​(m, 4H), 1.25 (m, 54H), 0.88 (t, J = 6.5 Hz, 6H). OH and NH are lost due to HD exchange. Mass spectrometry (ESI): m / z=734[M+H] +

[0064] Example 7 Synthesis of sphingomyelins (3-b13-e16) (1) [ka] 1.2 g of ceramide (2-b13-e16) and 1.5 g of phosphocholinating agent (1-i) were mixed and reacted with stirring for 16 hours at 120° C. The resulting reaction solution was purified by silica gel column chromatography (elution solvent: chloroform / methanol / water mixture) to obtain the desired sphingomyelin (3-b13-e16) (0.29 g, 19% yield). 1 H NMR (300 MHz, solvent: CDCl3:CD3OD = 2:1): δ = 4.44-4.37 (m, 2H), 4.25-4.20 (m, 1H), 4.15-4.06 (m, 1H), 3.99-3.90 (m, 1H), 3.65-3.50 (m, 4H), 3.21 (s, 9H), 2.20 (t, J = 7.5 Hz, 2H), 1.66-1.48 (m, 4H), 1.26 (m, 52H), 0.88 (t, J = 6.9 Hz, 6H). OH and NH are lost due to HD exchange. Mass spectrometry (ESI): m / z=750[M+H] +

[0065] Example 8 Synthesis of sphingomyelins (3-b13-e16) (2) [ka] 1.2 g of ceramide (2-b13-e16), 0.50 g of phosphocholinating agent (1-i), and 3 mg of iron(II) chloride were suspended in 3.50 g of methylcyclohexane, heated to 100°C with stirring, and then reacted for 16 hours. The resulting reaction solution was cooled to 40°C, and acetone was added and suspended. The solid was filtered from the resulting suspension. The resulting solid was purified by silica gel column chromatography (elution solvent: a mixture of chloroform / methanol / water) to obtain the desired sphingomyelin (3-b13-e16) (0.57 g, 38% yield). 1H NMR (300 MHz, solvent: CDCl3:CD3OD = 2:1): δ = 4.44-4.37 (m, 2H), 4.25-4.20 (m, 1H), 4.15-4.06 (m, 1H), 3.99-3.90 (m, 1H), 3.65-3.50 (m, 4H), 3.21 (s, 9H), 2.20 (t, J = 7.5 Hz, 2H), 1.66-1.48 (m, 4H), 1.26 (m, 52H), 0.88 (t, J = 6.9 Hz, 6H). OH and NH are lost due to HD exchange. Mass spectrometry (ESI): m / z=750[M+H] +

[0066] Example 9 Synthesis of sphingomyelins (3-b13-f15) (1) [ka] The synthesis was carried out in the same manner as in Example 7, except that the ceramide (2-b13-f15) was used instead of the ceramide (2-b13-e16) in Example 7, and the desired sphingomyelin (3-b13-f15) was obtained (0.30 g, yield 19%). 1 H NMR (300 MHz, solvent: CDCl3:CD3OD = 2:1): δ = 4.25-4.22 (m, 6H), 3.72-3.52 (m, 4H), 3.21 (s, 9H), 1.88-1.25 (m, 56H), 0.88 (t, J = 6.9 Hz, 6H). OH and NH are lost due to HD exchange. Mass spectrometry (ESI): m / z=766[M+H] +

[0067] Example 10 Synthesis of sphingomyelin (3-b13-f15) (2) [ka] The synthesis was carried out in the same manner as in Example 8, except that the ceramide (2-b13-f15) was used instead of the ceramide (2-b13-e16) in Example 8, and the desired sphingomyelin (3-b13-f15) was obtained (0.42 g, yield 27%). 1 H NMR (300 MHz, solvent: CDCl3:CD3OD = 2:1): δ = 4.25-4.22 (m, 6H), 3.72-3.52 (m, 4H), 3.21 (s, 9H), 1.88-1.25 (m, 56H), 0.88 (t, J = 6.9 Hz, 6H). OH and NH are lost due to HD exchange. Mass spectrometry (ESI): m / z=766[M+H] +

[0068] From the above, it was confirmed that sphingomyelins represented by general formula (3) can be produced in a single reaction by reacting a phosphocholinating agent represented by general formula (1) with a ceramide represented by general formula (2). It was also found that the yield can be significantly improved by using an iron catalyst. The resulting sphingomyelins can be used as active ingredients or components of lipid particles in the fields of pharmaceuticals and topical skin preparations.

Claims

1. A method for producing sphingomyelins represented by the following general formula (3), which comprises reacting a phosphocholinating agent represented by the following general formula (1) with a ceramide represented by the following general formula (2): 【Chemistry 1】 (In general formula (1), A is selected from the following structural formulas (i) to (x).) 【Chemistry 2】 (In the above structural formulas (i) to (x), R １ , R ２ , R ３ , R ４ , R ５ , R ６ , R ７ and R ８ each independently represents an alkyl group having 1 to 12 carbon atoms; R ９ and R １０ each independently represents an alkyl group, alkenyl group, or alkynyl group having 1 to 22 carbon atoms, and * indicates a bond. 【Transformation 3】 (In general formula (2), R ａ and R ｂ each independently represents an optionally substituted saturated or unsaturated hydrocarbon group. 【Chemistry 4】 (In general formula (3), R ａ and R ｂ is the same as the general formula (2).

2. R in general formula (2) ａ is selected from the following structural formulas (a) to (d), and R ｂ The method for producing sphingomyelins according to claim 1, wherein is selected from the following structural formulas (e) to (g): 【Transformation 5】 (In the above structural formulas (a) to (d), p is an integer of 0 to 26, q is an integer of 0 to 25, r is an integer of 0 to 24, s is an integer of 0 to 23, and * represents a bond.) 【Transformation 6】 (In the structural formulas (e) to (g), n is an integer of 0 to 28, m is an integer of 0 to 27, k is an integer of 0 to 28, and R Ｃ represents an optionally substituted saturated or unsaturated hydrocarbon group having 1 to 29 carbon atoms, and * represents a bond.

3. 3. The method for producing sphingomyelins according to claim 1, wherein A in general formula (1) is selected from the structural formulas (i), (ii), and (vi).

4. The method for producing sphingomyelins according to claim 1 or 2, wherein an iron catalyst is used as the catalyst.

5. The method for producing sphingomyelins according to claim 4, wherein the iron catalyst is iron chloride.

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