A process for the production of trans-zeatin

Abstract

The application discloses a production process of trans-zeatin, which comprises the following steps: refluxing E-2-(4-hydroxy-3-methyl-2-butene)-phthalimide with sodium hydroxide in methanol to obtain (E)-4-amino-1-hydroxy-2-methyl-2-butene; filtering and collecting the filtrate and concentrating the filtrate; and reacting the concentrated filtrate with 6-chloropurine in n-propanol and triethylamine as an acid-binding agent to finally obtain trans-zeatin. The application uses E-2-(4-hydroxy-3-methyl-2-butene)-phthalimide as a raw material, and high-purity trans-zeatin is obtained through two steps. The preparation method can effectively improve the yield of trans-zeatin, is simple and convenient to operate, is convenient for industrial popularization, and has good economic and social benefits.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a process for producing trans-zeatin. Background Technology

[0002] Trans-zein is a naturally occurring cytokinin in plants that plays a regulatory role in various aspects of plant growth and development. Besides promoting cell division, cytokinins can stimulate seed germination, fruit development, and flowering, and they also have the effect of preventing or delaying organ aging. Isolating trans-zein and its derivatives from plants is difficult, with low yields and high costs. Biological extraction cannot meet market demand. Currently, artificial synthesis is possible, and more than ten methods for synthesizing zein and its derivatives are known to date. However, obtaining high-purity products efficiently remains a technical challenge. Summary of the Invention

[0003] The purpose of this invention is to address the problems existing in the prior art by proposing a production process for trans-zeatin, which has a short process flow, high yield, and high purity of the obtained zeatin.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a production process for trans-zeatin, wherein the production process is as follows:

[0005] S1. Compound 1 and sodium hydroxide were added to methanol and heated to 60-68°C. The reaction was carried out for 2-4 hours, and the reaction progress was monitored by TLC. Compound 1 was named E-2-(4-hydroxy-3-methyl-2-butene)-phthalimide, wherein the mass ratio of methanol to E-2-(4-hydroxy-3-methyl-2-butene)-phthalimide and sodium hydroxide (methanol in liters, others in grams) was 1:100:50. After the reaction was completed, the mixture was cooled to room temperature and filtered under vacuum. The filter cake was washed with methanol, and the filtrate was collected. The filtrate was distilled under reduced pressure to obtain a pale yellow viscous oily compound 2, with a yield of 90.6%. Compound 2 was named (E)-4-amino-1-hydroxy-2-methyl-2-butene, and the reaction formula was:

[0006] S2. Add (E)-4-amino-1-hydroxy-2-methyl-2-butene obtained in step S1 to n-propanol, then add 6-chloropurine and triethylamine, stir and heat to 90℃, react for 3 hours, monitor the reaction progress by HPLC, the reaction endpoint is when the proportion of 6-chloropurine is less than 10%, evaporate excess triethylamine, cool to room temperature, a pale yellow solid appears, filter, wash the filter cake with water to obtain crude zein; the mass ratio of n-propanol to (E)-4-amino-1-hydroxy-2-methyl-2-butene, 6-chloropurine and triethylamine (unit: liter for n-propanol, grams for the others) is 1:60:100:100; recrystallize the crude product with ethanol, decolorize with activated carbon, to obtain a white zein product with a purity of over 99%. The reaction formula is:

[0007] The principle and beneficial effects of this invention are as follows: This invention discloses a method for preparing trans-zeatin. The method involves reacting E-2-(4-hydroxy-3-methyl-2-butene)-phthalimide with sodium hydroxide in methanol under reflux to obtain (E)-4-amino-1-hydroxy-2-methyl-2-butene. The filtrate is collected and concentrated by filtration, and then reacted with 6-chloropurine using n-propanol as solvent and triethylamine as an acid-binding agent to finally generate trans-zeatin.

[0008] This invention uses E-2-(4-hydroxy-3-methyl-2-butene)-phthalimide as a raw material and obtains high-purity trans-zeatin through a two-step reaction. The preparation method of this invention can effectively improve the yield of trans-zeatin, is simple to operate, convenient for industrial application, and has good economic and social benefits. Attached Figure Description

[0009] Figure 1 This is the HPLC chromatogram of trans-zeatin prepared according to the present invention.

[0010] Figure 2 This is the 1H NMR spectrum of trans-zeatin prepared in this invention.

[0011] Figure 3-5 This is a physical image of the trans-zeatin prepared according to the present invention. Detailed Implementation

[0012] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments should not be construed as limiting the present invention.

[0013] The production process of trans-zeatin in this embodiment is as follows:

[0014] S1. Add 1000 g of E-2-(4-hydroxy-3-methyl-2-butene)-phthalimide and 500 g of sodium hydroxide to 10 L of methanol, heat to 60-68 °C, and react for 2-4 h. Monitor the reaction progress by TLC. After the reaction is complete, cool to room temperature, filter under vacuum, wash the filter cake with 1 L of methanol, collect the filtrate, and distill the filtrate under reduced pressure to obtain 396.4 g of pale yellow viscous oil (E)-4-amino-1-hydroxy-2-methyl-2-butene, yield 90.6%.

[0015] S2. Add 300 g of (E)-4-amino-1-hydroxy-2-methyl-2-butene, 500 g of 6-chloropurine, and 500 g of triethylamine to 5 L of n-propanol. Stir and heat to 90 °C. After reacting for 3 hours, monitor the reaction progress with HPLC. The reaction endpoint is when the proportion of 6-chloropurine is less than 10%. Evaporate excess triethylamine, cool to room temperature, and a pale yellow solid appears. Filter, wash the filter cake with water to obtain crude zein. Recrystallize the crude product with ethanol and decolorize with activated carbon to obtain 580 g of off-white trans-zein with a purity of 99.53%, with a yield as high as 89.2%.

[0016] The detection results of the trans-zeatin obtained in this embodiment are shown in the figure. Figure 1 and Figure 2 ,from Figure 1 It can be seen from this that the trans-zeatin produced by this process has a chemical purity of up to 99.53%, with low total impurities and a maximum single impurity of no more than 0.5%; from Figure 2 The analysis shows that the trans-zeatin structure is correct, there is no residual solvent, and the product's chemical purity is consistent with the liquid chromatography spectrum. Figure 3-5 As can be seen from the embodiments of the present invention, the zein obtained is white in color, with uniform crystal particle size, and has good appearance and purity.

[0017] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A production process for trans-zeatin, characterized in that: The production process is as follows: S1. Compound 1 and sodium hydroxide were added to methanol and heated to 60-68°C. The reaction was carried out for 2-4 hours, and the reaction progress was monitored by TLC. The mass ratio of methanol to compound 1 and sodium hydroxide was 1:100:50 (L:g:g). After the reaction was completed, the mixture was cooled to room temperature and filtered under vacuum. The filter cake was washed with methanol, and the filtrate was collected. The filtrate was distilled under reduced pressure to obtain a pale yellow viscous oily compound 2, with a yield of 90.6%. S2. Compound 2 obtained in step S1 was added to n-propanol, followed by 6-chloropurine and triethylamine. The mixture was stirred and heated to 90°C. After reacting for 3 hours, the reaction progress was monitored by HPLC. The reaction endpoint was reached when the proportion of 6-chloropurine was less than 10%. Excess triethylamine was distilled off, and the mixture was cooled to room temperature. A pale yellow solid appeared. The solid was filtered, and the filter cake was washed with water to obtain crude zein. The mass ratio of n-propanol to compound 2, 6-chloropurine, and triethylamine was 1:60:100:

100. The crude product was recrystallized from ethanol and decolorized with activated carbon to obtain a white zein product with a purity of over 99%. The chemical structural formula of compound 1 is as follows: ; The chemical structural formula of compound 2 is: .

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