Method for preparing 1,2-naphthoquinone compound

A compound, naphthoquinone technology, applied in the field of preparation of chemical intermediates, can solve problems such as harsh labor protection conditions, difficulty in large-scale industrial production, and complex processing, and achieve the effects of high yield, low cost, and simple operation

Active Publication Date: 2014-01-29
CHINA GATEWAY PHARMA DEV CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The technical problem to be solved by the present invention is in order to overcome the low yield in the preparation method of existing 1,2-naphthoquinone compounds, need to use highly toxic oxidant, high cost, complex post-treatment of reaction waste liquid, serious environmental pollution, A kind of preparation method of 1,2-naphthoquinone compounds is provided due to the defects of harsh labor protection conditions and difficulty in large-scale industrial production

Method used

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  • Method for preparing 1,2-naphthoquinone compound
  • Method for preparing 1,2-naphthoquinone compound

Examples

Experimental program
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Embodiment 14

[0031] The preparation of embodiment 14-chloro-1,2-naphthoquinone

[0032] Add 2,4-dichloro-α-naphthol (21.3g, 0.1mol), acetic acid (400mL), sodium periodate (21.4g, 0.1mol) to the reaction flask in sequence at room temperature (25-30°C), Then stir and heat to 40°C and react until the 2,4-dichloro-α-naphthol disappears as traced by TLC. After the reaction, the reaction solution was cooled to room temperature, and water (300 mL) was added to dissolve unreacted sodium periodate. It was extracted with ethyl acetate (400 mL), dried and concentrated to give an orange solid with a yield of 82% and a purity of 99.4% (HPLC).

Embodiment 24

[0033] The preparation of embodiment 24-chloro-1,2-naphthoquinone

[0034] Add 2,4-dichloro-α-naphthol (21.3g, 0.1mol), propionic acid (400mL), sodium periodate (42.8g, 0.2mol) to the reaction flask in sequence at room temperature (25-30°C) , followed by stirring and heating to 50 ° C. The reaction was followed directly by TLC to complete the reaction of 2,4-dichloro-α-naphthol. After the reaction, the reaction liquid was cooled to room temperature, and water (300 mL) was added to dissolve unreacted sodium periodate. It was extracted with ethyl acetate (400 mL), dried and concentrated to give an orange solid with a yield of 85% and a purity of 99.2% (HPLC).

Embodiment 3

[0035] Example 3 The preparation of 4-chloro-1,2-naphthoquinone

[0036] Add 2,4-dichloro-α-naphthol (21.3g, 0.1mol), butyric acid (500mL), sodium periodate (64.2g, 0.3mol) to the reaction flask in sequence at room temperature (25-30°C) , followed by stirring and heating to 55 ° C. The reaction was followed directly by TLC to complete the reaction of 2,4-dichloro-α-naphthol. After the reaction, the reaction liquid was cooled to room temperature, and water (300 mL) was added to dissolve unreacted sodium periodate. It was extracted with ethyl acetate (400 mL), dried and concentrated to give an orange solid with a yield of 80% and a purity of 99.6% (HPLC).

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Abstract

The invention discloses a method for preparing a 1,2-naphthoquinone compound shown in the formula I, comprising the following step: in an organic solvent, a compound II carries out oxidation reaction under the action of periodate, thus obtaining a compound I, wherein R1 is hydrogen, chlorine, bromine, iodine or fluorine; R2 is hydrogen, C1-C6 alkyl, C6-C8 aryl or C1-C6 alkoxy; R3 is hydrogen, chlorine, bromine, C1-C6 alkyl or C1-C6 alkoxy; R4 is hydrogen, hydroxyl, C1-C6 alkyl or C1-C6 alkoxy; R5 is hydrogen, C1-C6 alkyl or C1-C6 alkoxy; R6 is hydrogen, C1-C6 alkyl or C1-C6 alkoxy; and R7 is hydrogen, C1-C6 alkyl or C1-C6 alkoxy. The preparation method is simple to operate, simple in post-treatment, low in cost, friendly to environment, higher in yield and purity and easy for industrial production.

Description

technical field [0001] The invention relates to a preparation method of a chemical intermediate, in particular to a preparation method of 1,2-naphthoquinone compounds. Background technique [0002] 1,2-Naphthoquinone compounds are important chemical intermediates, especially in pharmaceutical, pesticide and other industries, which have a very wide range of uses. [0003] Bhatt et al. (Synthesis, 1980, p943) reported that α-naphthol was oxidized to 1,2-naphthoquinones by using lead tetraacetate as an oxidant; [0004] Barton (Tetrahedron, 1988, Vol 44, p6397) et al reported that organic selenium (PhSeO) 2 Oxidation reaction with α-naphthol to generate corresponding 1,2-naphthoquinone compounds; [0005] Crandall (Tetrahedron Letters, 1991, Vol32, p5441) et al. reported that α-naphthol was oxidized to 1,2-naphthoquinones by dimethyldioxane; [0006] Krohm (Chem.Ber., 1989, Vol 122, p2323) et al reported molybdenum complex [Mo(O) 2 O]Py / HMPA is an oxidizing agent, and α-nap...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C46/06C07C50/10
Inventor 刘国斌匡通滔
Owner CHINA GATEWAY PHARMA DEV CO LTD
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