Method for making 6-bromocaproic acid

A technology of bromocaproic acid and hydrogen bromide, which is applied in the preparation of carboxylate, organic compound, carboxylate/lactone, etc., which can solve process difficulties, difficulties in post-processing of heavy metal chromium compounds, high production costs, etc. problems, to achieve the effect of simple process, easy to form large-scale production, and wide application prospects

Inactive Publication Date: 2006-11-22
FUDAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The method of S.Nandan uses chromium trioxide as an oxidant, which requires a large amount of expensive chromium trioxide to be consumed, resulting in high production costs
And in the production process, a large amount of waste of heavy metal chromium compounds is produced
And the reprocessing of a large amount of industrial waste heavy metal chromium compounds discharged is quite difficult, therefore, this method has no use value in industry
[0010] The method of S.Wolfe uses the more expensive hydrobromic acid acetic acid solution, which causes the production cost to be too high. Therefore, this method also has technical difficulties

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Embodiment 1: in the three-necked bottle of 500 milliliters, install thermometer, stirrer, add raw material ε-caprolactone (1 mole, 114 grams), normal hexane (200 milliliters), start to stir then. Dry hydrogen bromide gas (1.1 mol, 89 g) was introduced, and the reaction temperature was controlled at 20°C to 30°C. After completion of the hydrogen bromide gas sparging, the mixture was stirred at this temperature for an additional 6 hours. Then cool to 0~10°C and stir for 3 hours, a large amount of crystals are formed. After filtration, a light yellow solid of 6-bromohexanoic acid was obtained, weighing 183 g, with a yield of 95% and a purity of 99.2% (gas chromatography analysis).

Embodiment 2

[0019] Embodiment 2: in the three-necked bottle of 500 milliliters, install thermometer, stirrer, add raw material ε-caprolactone (1 mole, 114 grams), hexanaphthene (150 milliliters), start to stir then. Dry hydrogen bromide gas (1.2 mol, 97 g) was introduced, and the reaction temperature was controlled at 30°C~40°C. After completion of the hydrogen bromide gas sparging, the mixture was stirred at this temperature for an additional 5 hours. Then cool to 5~15°C and stir for 2 hours, a large amount of crystals are formed. After filtration, a light yellow solid of 6-bromohexanoic acid was obtained, weighing 180 g, with a yield of 92% and a purity of 99.4% (gas chromatography analysis).

Embodiment 3

[0020] Embodiment 3: in the three-necked flask of 500 milliliters, install thermometer, stirrer, add raw material epsilon-caprolactone (1 mole, 114 grams), toluene (200 milliliters), start to stir then. Dry hydrogen bromide gas (1.3 mol, 105 g) was introduced, and the reaction temperature was controlled at 40°C~50°C. After completion of the hydrogen bromide gas sparging, it was stirred at this temperature for an additional 4 hours. Then cool to 10~20°C and stir for 4 hours, a large amount of crystals are formed. After filtration, a light yellow solid of 6-bromohexanoic acid was obtained, weighing 185 g, with a yield of 95% and a purity of 99.1% (gas chromatography analysis).

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PUM

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Abstract

This invention relates to a method for producing 6-bromohexanoic acid, belonging to the organic compound production technology field.Wherein: vent the dry hydrogen bromide gas directly to the organic solvent containing sigma-caprolactone which can easily generate ring-opening reaction, to produce corresponding 6-bromohexanoic acid with high yield. Since 6-bromohexanoic acid is hard to dissolve in alkane, naphthene and aromatic solvent, it can cool the temperature below 30Deg C which is below the melting point of 6-bromohexanoic acid, to cause the 6-bromohexanoic acid to be crystals and obtain the precipitant. And then obtain the high-purity 6-bromohexanoic acid solid by filtration. This method is characterized of simple process, easy for mass production, broad application future and good economic benefits.

Description

technical field [0001] The invention belongs to the technical field of organic compounds, and in particular relates to a preparation method of 6-bromohexanoic acid. Background of the invention [0002] 6-bromohexanoic acid is a very important pharmaceutical intermediate, widely used in the preparation of medicine and veterinary medicine. At present, there is no domestic manufacturer producing it. The reason is that it is difficult to obtain high-purity products due to insufficient technology. Since the melting point of 6-bromohexanoic acid is low, that is, the melting point is 33-35°C, it is not easy to form crystals, and 6-bromohexanoic acid is generally obtained by distillation. But its boiling point is higher (bp 165-170 / 20mmHg), so it is not easy to distill. When the distillation temperature is high, 6-bromohexanoic acid is easy to debrominate and decompose, so it is difficult to obtain high-purity 6-bromohexanoic acid products. [0003] G.A Olah (Synthesis, 1982, Pag...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C53/19C07C51/09C07C51/363
Inventor 刘国斌
Owner FUDAN UNIV
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