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Preparation method for 2-methyl-1,4-naphthoquinone

A technology of methyl and naphthoquinone, which is applied in the field of preparation of 2-methyl-1,4-naphthoquinone, can solve the problem of low yield of 2-methyl-1-naphthol, low selectivity of oxidation reaction, unfavorable industrialization Production and other issues, to achieve the effects of environmental protection and green production, high reaction selectivity, and easy operation

Active Publication Date: 2019-02-26
XINFA PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] In this method, the yield of 2-methyl-1-naphthol prepared by methylation is low, and the reaction conditions for preparing 2-methyl-1,4-naphthoquinone by oxidation are harsh in addition, and the selectivity of oxidation reaction is low, which is not conducive to industrialization Production

Method used

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  • Preparation method for 2-methyl-1,4-naphthoquinone

Examples

Experimental program
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Embodiment 1

[0046] Embodiment 1: the preparation of 2-methyl-1,4-naphthoquinone

[0047] Add 200 g of toluene to a 500 ml four-necked flask connected with a stirring, thermometer, distillation device and constant pressure dropping funnel, heat to an internal temperature of 90-95°C, and drop 19.5 g (0.1 mole) of phthalate Dimethyl formate, 14.0 g (0.11 mole) of methyl 3-cyanobutyrate, 30 g (0.15 mole) of 27% sodium methoxide in methanol, while distilling off methanol, dropwise, and stirred at 100°C for 3 hours. Cool to 20-25°C, add 20 grams of 20% sodium hydroxide aqueous solution, stir and react at 20-30°C for 3 hours; connect the tail gas absorption device with lye, then add 30% hydrochloric acid to the reaction bottle to adjust the pH value 2.0-2.5, 60 ° C stirring reaction for 3 hours, decarboxylation dehydrocyanation; layered, the water layer was extracted with toluene 3 times, 50 grams each. The organic phases were combined, and the toluene was recovered by distillation to obtain 15...

Embodiment 2- Embodiment 4

[0050] 13 C NMR (100MHz, DMSO): δ = 16.8, 126.3, 126.2, 132.5, 132.1, 133.2, 133.9, 135.9, 148.8, 185.6, 185.8. Example 2-Example 4: Preparation of 2-methyl-1,4-naphthoquinone

[0051] As described in Example 1, the difference is that the raw materials, strong base, and solvent are changed, as shown in Table 1.

[0052] Table 1

[0053]

Embodiment 5

[0054] Embodiment 5: Preparation of 2-methyl-1,4-naphthoquinone

[0055] In a 500 ml four-necked flask connected with stirring, a thermometer, a distillation device and a constant pressure dropping funnel, add 200 grams of toluene and 17.0 grams of potassium tert-butoxide (0.15 moles), and heat to an internal temperature between 100-105 ° C. Add dropwise a mixed solution of 27.8 g (0.1 mole) of di-tert-butyl phthalate and 20.0 g (0.12 mole) of tert-butyl 3-cyanobutyrate, while distilling off tert-butanol, dropwise, and stir at 100°C for 3 hours . Cool to 20-25°C, add 20g of 20% sodium hydroxide aqueous solution, stir and react at 20-30°C for 3 hours; connect the tail gas absorption device with lye, then add 30% hydrochloric acid into the reaction bottle to adjust the pH value 2.0-2.5, 60 ° C stirring reaction for 3 hours; separate layers, the water layer was extracted with toluene 3 times, 50 grams each. The organic phases were combined, and the toluene was recovered by dist...

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Abstract

The invention relates to a preparation method for 2-methyl-1,4-naphthoquinone. The preparation method utilizes phthalic acid diester and 3-cyanobutyrate to prepare 2-methyl-1,4-naphthoquinone throughcondensation, hydrolysis and decarboxylation and hydrogen cyanide removal under the action of strong alkali. The preparation method is easy in raw material obtaining, cheap in price and high in reaction atomic economy; and the 3-cyanobutyrate can be obtained through addition reaction of by-product hydrogen cyanide and 2-crotonate; and the preparation method is easy to operate, less in waste wateramount and green and environmentally friendly in technology, and therefore the discharging of waste water without heavy metals can be realized, and industrial production can be achieved.

Description

technical field [0001] The invention relates to a preparation method of 2-methyl-1,4-naphthoquinone, which belongs to the field of pharmaceutical biochemical industry. Background technique [0002] Vitamin K3, also known as 2-methyl-1,4-naphthoquinone, menadione, etc., is a white or off-white crystalline powder with a very slight pungent smell, stable in the air, and decomposed by sunlight. Vitamin K3 can be used as procoagulant drugs to treat hemorrhagic diseases caused by vitamin K deficiency, such as neonatal hemorrhage, vitamin K deficiency and hypoprothrombinemia caused by intestinal malabsorption. At the same time, vitamin K3 is also an important complete feed additive, which can promote the synthesis of prothrombin in the liver of livestock and poultry, which is beneficial to their healthy growth. Therefore, vitamin K3 is of great significance to human health and the development of animal husbandry. [0003] There are three main synthetic routes of 2-methyl-1,4-napht...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C46/00C07C50/10
CPCC07C46/00C07C50/10
Inventor 戚聿新屈虎鞠立柱
Owner XINFA PHARMA
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