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Preparation method of p-hydroxybenzhydrazide compound

A technology for hydroxyphenylhydrazine and compounds, which is applied in the field of preparing p-hydroxyphenylhydrazine compounds, can solve problems such as poor selectivity, and achieve the effects of short reaction time, high product yield and good regioselectivity

Active Publication Date: 2020-07-03
HUBEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Several Lewis acid-catalyzed para-position carbon-hydrogen bond amination reactions of phenols and azodicarboxylates have been reported in the literature, but usually accompanied by the formation of ortho-aminated products with poor selectivity

Method used

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  • Preparation method of p-hydroxybenzhydrazide compound
  • Preparation method of p-hydroxybenzhydrazide compound
  • Preparation method of p-hydroxybenzhydrazide compound

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Preparation of Diethyl 1-(4-Hydroxyphenyl)hydrazine-1,2-dicarboxylate

[0023]

[0024] Add catalyst 3mol% Ag sequentially 2 O, 0.2mmol phenol, 0.4mmol diethyl azodicarboxylate, 2mL water and a No. 5 magnet. The reactor was placed in an ice bath to react for 0.5 hours. The reaction solution was poured into a separatory funnel, 15 mL of water was added, extracted 3 times with 10 mL of ethyl acetate, the obtained organic phases were combined, spin-dried by a rotary evaporator, and the crude product was separated and purified by column chromatography to obtain 1-(4-hydroxyl 48.8 mg of diethyl phenyl)hydrazine-1,2-dicarboxylate was a white solid with a yield of 91%.

[0025] Its structure was confirmed by H NMR and C NMR 1 H NMR (400MHz, CDCl 3 ):δ7.24(s,1H),6.99(s,1H),6.78–6.73(m,2H),5.43(s,1H),4.26–4.19(m,4H),1.30–1.25(m,6H ); 13 C NMR (100MHz, CDCl 3 ): δ156.7, 155.8, 155.3, 134.3, 127.0, 115.8, 63.3, 62.6, 14.5.

Embodiment 2

[0027] Preparation of Diisopropyl 1-(4-Hydroxyphenyl)hydrazine-1,2-dicarboxylate

[0028]

[0029] Add catalyst 3mol% Ag sequentially 2 O, 0.2mmol phenol, 0.4mmol diisopropyl azodicarboxylate, 2mL water and a No. 5 magnet. The reactor was placed in an ice bath to react for 0.5 hours. The reaction solution was poured into a separatory funnel, 15 mL of water was added, extracted 3 times with 10 mL of ethyl acetate, the obtained organic phases were combined, spin-dried by a rotary evaporator, and the crude product was separated and purified by column chromatography to obtain 1-(4-hydroxyl 47.4 mg of diisopropyl phenyl)hydrazine-1,2-dicarboxylate was a white solid with a yield of 80%.

[0030] Its structure was confirmed by H NMR and C NMR 1 H NMR (400MHz, CDCl 3 ):δ7.22–7.11(m,3H),6.69(d,J=8.32Hz,2H),5.02–4.92(m,2H),1.25(d,J=6.28Hz,12H),; 13 C NMR (100MHz, CDCl 3 ): δ156.4, 155.4, 155.2, 134.2, 126.7, 115.7, 71.1, 70.4, 22.1, 22.0.

Embodiment 3

[0032] Preparation of di-tert-butyl 1-(4-hydroxyphenyl)hydrazine-1,2-dicarboxylate

[0033]

[0034] Add catalyst 3mol% Ag sequentially 2 O, 0.2mmol phenol, 0.4mmol di-tert-butyl azodicarboxylate, 2mL water and a No. 5 magnet. The reactor was placed in an ice bath to react for 0.5 hours. The reaction solution was poured into a separatory funnel, 15 mL of water was added, extracted 3 times with 10 mL of ethyl acetate, the obtained organic phases were combined, spin-dried by a rotary evaporator, and the crude product was separated and purified by column chromatography to obtain 1-(4-hydroxyl 55.1 mg of di-tert-butyl phenyl)hydrazine-1,2-dicarboxylate (C-ac) was a white solid with a yield of 85%.

[0035] Its structure was confirmed by H NMR and C NMR 1 H NMR (400MHz, CDCl 3 ):δ7.18–7.12(m,2H),6.87(s,1H),6.65(d,J=8.24Hz,2H),6.54(s,1H),1.48(s,18H); 13 C NMR (100MHz, CDCl 3 ): δ155.6, 154.7, 134.7, 126.5, 115.6, 82.4, 81.8, 28.4, 28.3.

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Abstract

The invention relates to a preparation method of a p-hydroxybenzhydrazide compound. The preparation method comprises the following steps: sequentially adding a catalyst Ag2O, a reactant I, a reactantII and water into a reactor, and putting the reactor into an ice bath for a reaction for 0.5-10 hours; and extracting a reaction solution with an organic solvent, carrying out reduced-pressure distillation on an organic phase to obtain a crude product, and carrying out column chromatography separation and purification to obtain the p-hydroxybenzhydrazide compound. According to the method, raw materials are cheap and easy to obtain, reactions are carried out in a water phase of a green solvent, reaction time is short, reaction conditions are simple and mild, regioselectivity is good, and the produced p-hydroxybenzhydrazide compound has important application value in organic synthesis.

Description

technical field [0001] The invention relates to a method for preparing p-hydroxyphenylhydrazine compounds through transition metal-catalyzed para-position carbon-hydrogen bond amination of phenol compounds. Background technique [0002] The phenolic moiety is ubiquitous in natural products, dyes, pharmaceuticals, and materials, and is a cheap and readily available starting material for building molecules of other compounds in the chemical sciences. Therefore, the selective functionalization of phenolic compounds is of great interest. Because phenols are prone to electrophilic aromatic substitution at the ortho and para positions, but the electron densities at the ortho and para positions are not much different, the selectivity of the two positions is difficult to control. Over the past decade, progress has been made in the transition metal-catalyzed functionalization of ortho carbon–hydrogen bonds in phenolics with the assistance of hydroxyl-mounted directing groups on phen...

Claims

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Application Information

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IPC IPC(8): C07C281/02
CPCC07C281/02
Inventor 李栋赵瑞楠张谦
Owner HUBEI UNIV OF TECH
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