Method for synthesizing azacycloheptane

An azacycloheptane and a synthesis method technology, applied in the direction of organic chemistry and the like, can solve the problems of decreased product yield and purity, difficult commercial reduction system, poor reduction effect, etc., to reduce purification costs and facilitate large-scale industrialization Application, the effect that is beneficial to environmental protection

Inactive Publication Date: 2013-12-04
UNIV OF SHANGHAI FOR SCI & TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0009] However, the above-mentioned methods all use hydrogen as a reducing agent, and the reaction needs to be carried out under heating and pressure. The reaction conditions are harsh and the requirements for equipment are high; Causes a decline in product yield and purity
In addition, the above methods all require heavy metals as catalysts, which are not only expensive, but also easy to cause heavy metal pollution, which is not conducive to environmental protection.
If conventional chemical reducing agents are used, there are still problems such as commercially difficult realization of the reduction system, poor reduction effect, and low conversion rate. Therefore, the large-scale industrial application of these methods is limited to a certain extent.

Method used

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  • Method for synthesizing azacycloheptane

Examples

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Effect test

Embodiment 1

[0031] Put 150mL of anhydrous tetrahydrofuran in a dry reaction bottle, cool down to 0°C, and add 33.3g of anhydrous aluminum trichloride (0.25mol) and 10.0g of sodium borohydride (0.26mol) in turn after argon replacement, and wait for the reaction liquid to naturally After raising the temperature to 25°C, stir for 1 hour, add 11.3g of caprolactam (0.1mol) and raise the temperature of the reaction solution to 50°C, reflux for 8 hours, then cool the reaction solution to 0°C, add 500mL of water, stir until the reaction solution is clear, and use 2M Potassium hydroxide solution adjusts the pH to ≥ 12, extracts the reaction solution 3 times with 300 mL of dichloromethane and combines the organic phases, washes the organic phase with 60 mL of saturated brine, dries over anhydrous magnesium sulfate, concentrates the filtrate to recover the solvent to obtain a crude product, usually The crude product was distilled under pressure, and the fractions between 137 and 140°C were collected ...

Embodiment 2

[0033] Put 150mL of anhydrous tetrahydrofuran in a dry reaction bottle, cool down to 0°C, add 36.1g of anhydrous aluminum trichloride (0.27mol) and 15.2g of sodium borohydride (0.28mol) in turn after nitrogen replacement, and wait for the reaction liquid to heat up naturally After reaching 25°C, stir for 1 hour, add 11.3g caprolactam (0.1mol) and raise the temperature of the reaction solution to 55°C, reflux for 8 hours, then cool the reaction solution to 0°C, add 500mL of water, stir until the reaction solution is clear, and oxidize with 2M hydroxide Adjust the pH of the sodium solution to ≥12, extract the reaction solution 3 times with 300 mL of dichloromethane and combine the organic phases, wash the organic phase with 60 mL of saturated brine, dry over anhydrous magnesium sulfate, concentrate the filtrate to recover the solvent to obtain a crude product, and reduce The crude product was distilled under pressure, and the fraction between 54 and 58°C was collected to obtain 9...

Embodiment 3

[0035] Put 150mL of anhydrous tetrahydrofuran in a dry reaction bottle, cool down to 0°C, add 36.1g of anhydrous aluminum trichloride (0.27mol) and 15.2g of sodium borohydride (0.28mol) in turn after nitrogen replacement, and wait for the reaction liquid to heat up naturally After reaching 25°C, stir for 1 hour, add 11.3g of caprolactam (0.1mol), introduce nitrogen to raise the pressure to 1520mmHg and raise the temperature of the reaction solution to 65°C, reflux for 10h, then cool the reaction solution to 0°C, add 500mL of water, and stir until the reaction The liquid was clarified, and the pH was adjusted to ≥12 with 2M sodium hydroxide solution, the reaction liquid was extracted 3 times with 300 mL of dichloromethane and the organic phase was combined, washed with 60 mL of saturated brine, dried over anhydrous sodium sulfate, and the filtrate was concentrated and recovered The solvent was used to obtain a crude product, which was distilled under reduced pressure at 40 mmHg,...

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Abstract

The invention belongs to the field of organic synthesizing, and relates to a method for synthesizing azacycloheptane. The comprises the following steps: caprolactam under the shielding of inert gas in an organic solvent is reduced into azacycloheptane through a metal reducer; the azacycloheptane is extracted, cleaned, dried, concentrated and distilled into a pure azacycloheptane product of which the mass fraction is equal to or larger than 98 percent. The method has the advantages that the raw material is cheap and easy to obtain; the synthesizing steps are easy; the reaction condition is mild; the product yield and the purity are high; the industrialized application prospect is favorable.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and relates to a synthesis method of azepane, in particular to a method in which caprolactam is reduced by a metal reducing agent in an organic solvent to form azepane under the protection of an inert gas. Background technique [0002] Azacycloheptane, also known as hexamethyleneimine (HMI for short), homopiperidine, molecular formula C 6 h 13 N, the relative molecular weight is 99.18, the CAS number is 111-49-9, and the structural formula is: [0003] Azepane is an important chemical synthesis intermediate, which is widely used in medicine, pesticide, petrochemical and other fields. At present, azepane is mostly synthesized in industry by using hexamethylenediamine or caprolactam as raw materials through hydrogenation reduction. Among them, the process of synthesizing azepane with hexamethylenediamine as raw material has been basically eliminated at present, because hexamethylenediamine is ...

Claims

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Application Information

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IPC IPC(8): C07D295/027C07D295/023
Inventor 熊非张淑平李少阳
Owner UNIV OF SHANGHAI FOR SCI & TECH
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