Process for the preparation of 2,5-furandimethanamine from 5-(azidomethyl)furan-2-carboxaldehyde

Abstract

The application discloses a method for preparing 2,5-furandimethanamine by 5-(azidomethyl)furan-2-formaldehyde, which comprises the following steps: mixing 5-hydroxymethylfurfural, azidophosphoric acid diphenyl ester and toluene; adding 1,8-diazabicyclo[5.4.0]undec-7-ene into the mixed solution in batches, stirring and reacting; obtaining 5-(azidomethyl)furan-2-formaldehyde through post-treatment; placing 5-(azidomethyl)furan-2-formaldehyde, Raney nickel and a methanol solution of ammonia into an autoclave, and introducing 0.4-0.8 MPa hydrogen into the autoclave to react at 40-60 DEG C for 12-20 hours to obtain a reaction liquid; concentrating and removing the solvent from the reaction liquid to obtain a liquid; and performing vacuum distillation on the obtained liquid to obtain 2,5-furandimethanamine. The application solves the problems of low production yield, high production cost, high reaction risk and non-industrial production of 2,5-furandimethanamine in the prior art.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of preparing 2,5-furan dimethylamine, in particular to a method for preparing 2,5-furan dimethylamine by 5-(azidomethyl)furan-2-carboxaldehyde. BACKGROUND

[0002] 2,5-furan dimethylamine is an important biomass-derived platform compound, which has applications in chemical industry, agriculture, medical treatment and other fields. There are also a large number of amine substances in some pharmaceutical intermediates and life macromolecules.

[0003] At present, most of the methods for synthesizing 2,5-furan dimethylamine are still using ammonia gas and hydrogen gas catalytic reaction, which is high in cost and not conducive to large-scale production due to the strong corrosiveness of ammonia gas. Another method uses common metals for reduction, but the reaction process is not clear, the yield is extremely low, the reaction is dangerous, and the post-processing method is extremely complex, which is not suitable for large-scale production.

[0004] A method for preparing 2,5-furan dimethylamine is disclosed in Chinese patent application No. CN113149937A (application No. 202110309620.3), which provides a method for preparing 2,5-furan dimethylamine by one-pot two-step catalysis of 5-hydroxymethylfurfural. 5-hydroxymethylfurfural is used as the reaction substrate, and in the first step, the 5-hydroxymethylfurfural is catalytically oxidized and aminated by a metal oxide catalyst in a methanol or ethanol solution of methylamine to obtain an intermediate product; in the second step, the intermediate product obtained in the first step is catalytically converted by a supported catalyst in a methanol or ethanol solution of ammonia to obtain 2,5-furan dimethylamine, and the two-step reaction is carried out in one pot. The method uses widely available reaction raw materials, has renewability, simple and efficient reaction process, mild reaction conditions, simple product separation and purification, simple catalyst preparation, and reusable catalyst. The technical scheme uses ammonia gas and hydrogen gas catalytic reaction, which is high in cost and not conducive to large-scale production due to the strong corrosiveness of ammonia gas. SUMMARY

[0005] The purpose of the present application is to provide a method for preparing 2,5-furan dimethylamine by 5-(azidomethyl)furan-2-carboxaldehyde, in order to solve the problems of low production yield, high production cost, high reaction danger and inability to industrialize production of 2,5-furan dimethylamine in the prior art.

[0006] In order to solve the above problems, the present application provides a method for preparing 2,5-furan dimethylamine by 5-(azidomethyl)furan-2-carboxaldehyde, which comprises the following steps:

[0007] S1, placing 5-hydroxymethylfurfural, diphenyl azide phosphate and toluene in a container to obtain a mixed solution;

[0008] S2, 1,8-diazabicyclo[5.4.0]undec-7-ene is added to the mixed solution obtained in S1 in batches, and the reaction is stirred;

[0009] S3, water and ethyl acetate are added to the solution after the reaction in S2, and the solution is stirred;

[0010] S4, the solution after stirring in S3 is subjected to two-phase separation, the organic phase is washed with saturated sodium bicarbonate solution, and the obtained organic phase is rotary dried to obtain 5-(azidomethyl)furan-2-carboxaldehyde;

[0011] S5, the 5-(azidomethyl)furan-2-carboxaldehyde obtained in S4, Raney nickel and ammonia methanol solution are placed in an autoclave, and 0.4-0.8 MPa hydrogen gas is introduced at a temperature of 40-60°C for 12-20 hours to obtain a reaction liquid;

[0012] S6, the reaction liquid obtained in S5 is concentrated to remove the solvent to obtain a liquid;

[0013] S7, the liquid obtained in S6 is subjected to reduced pressure distillation to obtain 2,5-furandimethanamine.

[0014] The molar ratio of 5-hydroxymethylfurfural, diphenyl phosphorazide and 1,8-diazabicyclo[5.4.0]undec-7-ene is 0.73-0.93:0.9-1.1:0.9-1.1, and most preferably 0.236 mol:0.283 mol:0.283 mol.

[0015] In step S2, 1,8-diazabicyclo[5.4.0]undec-7-ene is added to the mixed solution obtained in S1 in batches.

[0016] In step S2, the reaction is stirred at 5-15°C.

[0017] In step S2, the mass ratio of 5-(azidomethyl)furan-2-carboxaldehyde and Raney nickel is 0.8-1.2:0.3-0.7, and most preferably 1:0.5.

[0018] In step S5, 0.5-0.7 MPa hydrogen gas is introduced at a temperature of 45-55°C for 15-18 hours, and most preferably 0.6 MPa hydrogen gas is introduced at a temperature of 50°C for 16.5 hours.

[0019] Further preferably, the method for preparing 2,5-furandimethanamine from 5-(azidomethyl)furan-2-carboxaldehyde comprises the following steps:

[0020] S1, 5-hydroxymethylfurfural, diphenyl phosphorazide and toluene are placed in a container, and cooled;

[0021] S2, slowly add 1,8-diazabicyclo[5.4.0]undec-7-ene to the solution obtained in S1, and stir the reaction at low temperature for one hour;

[0022] S3, slowly add water and ethyl acetate to the solution in S2, and stir the reaction;

[0023] S4, separate the mixed solution in S3 into two phases, wash the organic phase with saturated sodium bicarbonate solution, and dry the obtained organic phase to obtain a yellow-brown liquid product;

[0024] S5, place the product obtained in S4, Raney nickel and a methanol solution of ammonia into an autoclave, and introduce 0.6 MPa hydrogen gas into the autoclave, and react at 50℃ for 16.5 hours;

[0025] S6, concentrate the liquid obtained in S5 to remove the solvent to obtain a liquid;

[0026] S7, perform vacuum distillation on the liquid obtained in S6 to obtain a light yellow liquid, which is the target product furan dimethylamine.

[0027] Compared with the prior art, the present application has the following advantages:

[0028] The present application uses 5-(azidomethyl)furan-2-carboxaldehyde to prepare 2,5-furan dimethylamine, avoids the use of a large amount of ammonia gas in one step of hydrogenation, has fewer by-products in the reaction process, and the by-products are easy to remove, and the purification method is suitable for large-scale chemical production.

[0029] The present application has a short reaction time, high efficiency, low reaction temperature, low energy consumption, low overall reaction risk, low cost, simple purification method, and is suitable for large-scale industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The reaction scheme for synthesizing the compound of the present application is shown in the figure.

[0031] Figure 2 The nuclear magnetic resonance spectrum of the compound of the present application is shown in the figure.

[0032] Figure 3 The gas chromatogram of the compound of the present application is shown in the figure. DETAILED DESCRIPTION

[0033] As shown in the figure, the reaction scheme for synthesizing the compound of the present application is shown in the figure. Figure 1

[0034] Example 1 Synthesis of 5-(azidomethyl)furan-2-carboxaldehyde

[0035] ​1,8-diazabicyclo[5.4.0]undec-7-ene (43 g, 0.283 mol) was added slowly to a stirred solution of 5-hydroxymethyl-2-furaldehyde (30 g 99%, 0.236 mol), diphenyl phosphorazide (77.7 g, 0.283 mol) and toluene (150 mL) at 10 °C; TLC monitoring showed no starting material spot and the reaction was complete; water (90 mL) was added to the reaction mixture; the aqueous layer was extracted with ethyl acetate (3 x 30 mL); the organic layer was washed with saturated sodium bicarbonate solution; the organic layer was dried under vacuum to obtain 31.6 g of dark brown liquid product, 5-(azidomethyl)furan-2-carbaldehyde.

[0036] Example 2 Synthesis of 2,5-furandimethylamine

[0037] 5-(azidomethyl)furan-2-carbaldehyde (1 g, 0.007 mol), Raney nickel (0.5 g) and ammonia in methanol (5 ml) were taken in a 50 mL high pressure reaction vessel at 25 °C and hydrogen was introduced at 0.6 MPa and the reaction was carried out at 50 °C for 16.5 h. The solvent was distilled off and the resulting mixture was distilled to obtain 0.6 g of yellow clear liquid (yield 71.86%, purity 98.03%) as shown in the H-NMR spectrum of yellow liquid and Figure 2 H-NMR spectrum of yellow liquid and Figure 3 Gas chromatogram, the product obtained was 2,5-furandimethylamine, having the structure as shown below:

[0038]

Claims

1. A process for the preparation of 2,5-furandimethanamine from 5-(azidomethyl)furan-2-carbaldehyde, characterized in that, The method comprises the following steps: S1, placing 5-hydroxymethylfurfural, diphenyl phosphorazide and toluene in a container to obtain a mixed solution; S2, adding 1,8-diazabicyclo[5.4.0]undec-7-ene into the mixed solution obtained in S1 in batches, and stirring the reaction at 5-15℃; The molar ratio of 5-hydroxymethylfurfural, diphenyl phosphorazide and 1,8-diazabicyclo[5.4.0]undec-7-ene is 0.73-0.93:0.9-1.1:0.9-1.1; S3, adding water and ethyl acetate into the solution after the reaction in S2, and stirring; S4, performing two-phase separation on the solution after the stirring in S3, washing the organic phase with saturated sodium bicarbonate solution, and obtaining 5-(azidomethyl)furan-2-carboxaldehyde by rotary evaporation of the obtained organic phase; S5, placing 5-(azidomethyl)furan-2-carboxaldehyde, Raney nickel and ammonia methanol solution in an autoclave, and introducing 0.4-0.8 MPa hydrogen at 40-60℃ for 12-20 hours to obtain a reaction liquid; The mass ratio of 5-(azidomethyl)furan-2-carboxaldehyde and Raney nickel is 0.8-1.2:0.3-0.7; S6, concentrating and removing the solvent from the reaction liquid obtained in S5 to obtain a liquid; S7, performing vacuum distillation on the liquid obtained in S6 to obtain 2,5-furandimethanamine.

2. The process for the preparation of 2,5-furandimethanamine from 5- (azidomethyl)furan-2-carboxaldehyde according to claim 1, characterized in that, In step S5, 0.5-0.7 MPa hydrogen is introduced at 45-55℃ for 15-18 hours.

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