Prepn process of 1-fluoronaphthalene

A technology of fluoronaphthalene and naphthylamine, which is applied in the field of preparation of 1-fluoronaphthalene, can solve the problems of difficult industrial production, difficult realization of fluorinating agent equipment, and many by-products at reaction temperature.

Active Publication Date: 2007-01-03
SHANGHAI CHEMSPEC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although this method overcomes the shortcomings of high reaction temperature and many by-products of the above-mentioned halogen-fluorine exchange reaction, the fluorinating agent used and its process and equipment are difficult to realize and industrialized production

Method used

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  • Prepn process of 1-fluoronaphthalene
  • Prepn process of 1-fluoronaphthalene

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preparation example Construction

[0017] The preparation method of 1-fluoronaphthalene of the present invention uses 1-naphthylamine as a raw material, undergoes diazotization to form diazonium fluoroborate or diazonium fluorophosphate, and then conducts thermal decomposition to form 1-fluoronaphthalene product.

[0018] Specifically, the preparation method of 1-fluoronaphthalene comprises the following steps:

[0019] (1) 1-naphthylamine is reacted with nitrous acid, nitrite or nitrite in an acidic medium to obtain a diazonium salt;

[0020] (2) reacting the diazonium salt obtained in step (1) with fluoroboric acid or its salt or fluorophosphoric acid or its salt to obtain diazonium fluoroborate or diazonium fluorophosphate;

[0021] (3) Thermally decomposing the diazonium fluoroborate or diazonium fluorophosphate obtained in step (2) to obtain 1-fluoronaphthalene.

[0022] In step (1), the acidic medium can be any medium suitable for providing an acidic environment for the diazotization reaction, including ...

Embodiment 1

[0035] Add 143 grams (equivalent to 1 mole) of 1-naphthylamine and 400ml hydrochloric acid solution into a 2000ml four-neck flask, keep the temperature at 50-60°C and stir for about half an hour, then cool the temperature of the reaction solution to -3°C, add dropwise Add 250ml of 40% sodium nitrite aqueous solution (equivalent to 1.1 mole of sodium nitrite), add dropwise for about 2 hours, and keep warm for about half an hour. Then, 308ml of 40% fluoroboric acid aqueous solution (equivalent to 1.4 moles of fluoroboric acid) was added dropwise, and fine solids were formed immediately, and the dropwise addition lasted for about half an hour. After stirring for 1 hour, suction filtration, washing, and drying gave diazonium fluoroboron Salt solid 222.8 grams.

[0036] Heat a 1000ml four-necked bottle with the temperature controlled at 70-75°C, put in the solid diazonium fluoroborate obtained above in batches, and make it thermally decompose. After the decomposition is completed, ...

Embodiment 2

[0038] Add 143 grams (equivalent to 1 mole) of 1-naphthylamine and 450ml of sulfuric acid solution into a 2000ml four-necked bottle, keep the temperature at 60-70°C and stir for about half an hour, then cool the temperature of the reaction solution to 5°C, and add 40 % sodium nitrite aqueous solution 680ml (equivalent to 3.0 moles of sodium nitrite), continue to add dropwise for about 2 hours, and keep warm for about half an hour. Then, 270ml of 40% sodium fluoroborate aqueous solution (equivalent to 1.2 moles of sodium fluoroborate) was added dropwise, and fine solids were formed immediately, and the dropwise addition continued for about half an hour. After stirring for 1 hour, suction filtered, washed, and dried to obtain diazo Fluoroborate solid 232 grams.

[0039]Heat a 1000ml four-neck bottle, control the temperature at 140-150°C, put in the solid diazonium fluoroborate obtained above in batches, and make it thermally decompose. After the decomposition is completed, recti...

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Abstract

The preparation process of 1-fluoronaphthalene includes the following steps: (1) reacting 1-naphthylamine with nitrous acid, nitrous acid ester or nitrite in acid medium to obtain diazo salt; (2) reacting the diazo salt with fluoroboric acid or its salt or fluorophosphoric acid or its salt to obtain diazo fluoroborate or diazo fluorophosphate; and (3) heating the diazo fluoroborate or diazo fluorophosphate to decompose to obtain 1-fluoronaphthalene. The process has short synthesis path, less side products, mild reaction condition, easy control, relatively low cost, great production capacity, high product purity and other advantages, and the product is used as medicine intermediate.

Description

technical field [0001] The present invention relates to the preparation method of 1-fluoronaphthalene. Background technique [0002] 1-Fluoronaphthalene is a pharmaceutical intermediate developed in recent years. Replacing a hydrogen atom on an aromatic ring with a fluorine atom often has a strong and unexpected effect on the biological activity of the compound. In biologically active molecules, replacement of a hydrogen atom with a fluorine atom often results in a similar compound with increased or improved biological activity. [0003] In the prior art, fluorination can be carried out by direct fluorination with a fluorinating agent. However, direct fluorination requires special reagents and equipment, is expensive, and the technology is immature, so it is not suitable for industrial production. Fluorination can also be carried out in the form of nucleophilic substitution via halogen-fluorine exchange reactions. However, this reaction often needs to be carried out at a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C25/22C07C17/14
Inventor 袁云龙陈莹敏
Owner SHANGHAI CHEMSPEC CORP
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