Method for preparing 5-nitro vanillin

A technology of nitrovanillin and vanillin, applied in the field of preparation of 5-nitrovanillin, which can solve the problems of complex product separation process, large amount of waste acid waste water, increased side reactions, etc., and shorten the reaction time , low production cost and easy operation

CN102304051AInactive Publication Date: 2012-01-04HUAIYIN TEACHERS COLLEGE
4 Cites 2 Cited by

Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2012-01-04
Estimated Expiration
Not applicable · inactive patent

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention discloses a method for preparing 5-nitro vanillin. The method comprises the following specific steps of: dissolving vanillin and ceric ammonium nitrate in 5-90% by volume of acetic acid according to the weight ratio of the vanillin to the ceric ammonium nitrate of 1:(0.6-1.6), adding polyethylene glycol-400 as a phase transfer catalyst according to the mol ratio of the polyethylene glycol-400 to the vanillin of 1:1.25, reacting at 20-60 DEG C for 1.0-2.5 h under magnetic stirring, tracking by TLC (Thin Layer Chromatography), wherein a developing agent includes ethyl acetate and petroleum ether in the ratio of 1:1, and stopping stirring after a reactant is completely converted into a product; and pouring a mixture into proper ice water, separating out yellow solid, and obtaining the 5-nitro vanillin product by filtering, washing, drying and re-crystallizing. According to the method disclosed by the invention, the green chemical product, namely ceric ammonium nitrate, is used as a nitration reagent; the polyethylene glycol-400 is used as the phase transfer catalyst; and the method has the advantages of short reaction time, few by-products, simplicity and convenience for operation and low production cost.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to a preparation method of a compound, in particular to a preparation method of 5-nitrovanillin. Background technique

[0002] 5-nitrovanillin, the systematic name is 3-methoxy-4-hydroxy-5-nitrobenzaldehyde. Mainly used in the fields of medicine and spices, it can be used in the synthesis of 3,5-disubstituted catechols catechol-O-methyltransferase (COMT-I) inhibitor tolcapone, or as a synthetic advantage Precursor for the biosynthesis of famycin antibiotics (3-hydroxymethoxyrifamycin, 3-hydroxyrifamycin). The preparation method of 5-nitrovanillin is mainly through the vanillin nitration method, that is, the vanillin is used as a raw material, and nitric acid is used as a nitrating agent to obtain it in an organic solvent. However, this method uses a large amount of acid and a large amount of waste acid waste water, which is not conducive to environmental protection. Simultaneously, because the strong oxidizing property of nitri...

Examples

Embodiment 1

[0013] In a 25mL Erlenmeyer flask, add 0.152g (1mmol) vanillin, 2mL volume fraction 90% acetic acid, 0.50g (1.25mmol) polyethylene glycol-400, slowly drop in 0.09g (0.58mmol) under stirring condition Aqueous solution of ammonium cerium nitrate, reacted at 20°C for 2.5 hours, tracked by TLC, developer: ethyl acetate: petroleum ether = 1: 1, stop stirring when the reactant is completely converted into product; pour the reactant into an appropriate amount of ice water , a yellow solid was precipitated, suction filtered, and the solid was washed 2-3 times with distilled water to obtain the crude product of 5-nitrovanillin; weighing: 0.14g, yield: 71%; the product was determined by melting point and infrared The spectrum and proton nuclear magnetic resonance spectrum analysis are consistent with the literature reports; the measured melting point is: m.p: 177.2~178.6 ℃;

[0014] IR: ν max (KBr pellets, cm -1 ), 3203, 3077, 2945, 2876, 1685, 1611, 1548, 1402, 1335, 1269, 1231, 1103...

Embodiment 2

[0016] In a 100mL Erlenmeyer flask, add 0.76g (5mmol) vanillin, 10mL volume fraction 90% acetic acid, 2.5g (6.25mmol) polyethylene glycol-400, slowly drop in 0.76g (4.9mmol) under stirring condition Aqueous solution of ammonium cerium nitrate; react at 40°C for 1.5 hours, tracked by TLC, developer: ethyl acetate: petroleum ether = 1:1, stop stirring when the reactant is completely converted into product; pour the reactant into an appropriate amount of ice water , a yellow solid was precipitated, suction filtered, and the solid was washed 2-3 times with distilled water to obtain the crude product of 5-nitrovanillin; weighing: 0.68g, yield: 69%; the measured melting point was: m.p : 177.5~178.6 ℃.

Embodiment 3

[0018] Add 15.2g (100mmol) vanillin, 200mL volume fraction 90% acetic acid, 50.0 g (125 mmol) polyethylene glycol-400 into a 1000mL round-bottomed flask, slowly drop into 24.32g (158 mmol) ) aqueous solution of ammonium cerium nitrate, reacted at 60°C for 1.0 hour, tracked by TLC, developer: ethyl acetate: petroleum ether = 1: 1, stop stirring when the reactant is completely converted into product; pour the reactant into an appropriate amount of ice In the water, a yellow solid was precipitated, filtered by suction, and washed with distilled water for 2-3 times to obtain a crude product of 5-nitrovanillin; weighing: 13.8 g, yield: 70%. The measured melting point is: m.p: 177.5~178.5 ℃.