• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The present invention comprises the following steps: (1) Melting 4-cyanopyridine: placing 4-cyanopyridine crystal in a reactor at normal pressure and adjusting the temperature of the reactor to 80 ° C to 90 ° C to prevent the melting of 4-cyanopyridine. Crystal, (2) cooling: regulating the temperature of the reactor and lowering the temperature of the molten 4-cyanopyridine according to a certain cooling rate to 71.5 ° C to 73.5 ° C, (3) crystallization: maintaining the temperature at 71.5 ° C ºC to 73.5 ºC to conduct crystallization; and (4) Separation and extraction: Discharge the base solution which does not form a crystal, raise the temperature of the reactor back to 80 ºC to 90 ºC, and melt the crystal to give the final product of 4-cyanopyridine. The invention is characterized by a simple manufacturing method and thereby preventing a peritectic phenomenon by controlling the cooling rate during cooling for crystallization. In addition, a high overall yield and purity of the end product are achieved without creating by-product pollutants.
    公开号:BE1027319B1
    申请号:E20205432
    申请日:2020-06-16
    公开日:2021-01-13
    发明作者:Qian Qian；Jingcheng Yang；Lei Xu；Zhaobing Cao；xingfu Ma
    申请人:Anhui Redpont Biotechnology Co Ltd；
    IPC主号:
    专利说明:

    Process for the purification of 4-cyanopyridine by melt crystallization
    FIELD OF THE INVENTION The present invention relates to the field of the production of 4-cyanopyridine, specifically to a process for the purification of 4-cyanopyridine by melt crystallization.
    BACKGROUND ART 4-Cyanopyridine, also known as isonicotinonitrile, is a major by-product of 3-methylpyridine in the production of 3-cyanopyridine by ammoxidation. 4-cyanopyridine is an important intermediate of medicine, pesticide and dye. For example, isoniazıd, an anti-tuberculosis drug, is made from 4-cyanopyridine. In order to obtain 4-cyanopyridine with a high purity, purification and refining are required. At present, in the industrial separation, a vacuum distillation method is mainly used to separate 4-cyanopyridine from the mixed system of 3-cyanopyridine and 4-cyanopyridine, thus improving the economic advantages. The deposition result of 4-cyanopyridine in industrial production is unsatisfactory and the running cost is high. With economic cost in mind, manufacturing companies usually treat the homologous 3/4-cyanopyridine mixture containing 4-cyanopyridine as waste or incinerate it directly as chemical waste, resulting in a low recovery rate of the homologous cyanopyridine mixture and severe waste and pollution leads.
    DISCLOSURE OF THE INVENTION In view of the above problem, it is an object of the present invention to provide a method for purifying 4-cyanopyridine by melt crystallization. According to the invention, the object is achieved by the following configuration: A method for purifying 4-cyanopyridine by melt crystallization, comprising the following steps: (1) Melting 4-cyanopyridine: Placing 4-cyanopyridine crystals in a reactor at normal pressure and setting the Temperature of the reactor to 80 ° C to 90 ° C to cause the 4-cyanopyridine crystal to melt,
    (2) Cooling: regulating the temperature of the reactor and lowering the temperature of the molten 4-cyanopyridine to 71.5 ° C to 73.5 ° C according to a certain cooling rate, (3) Crystallization: maintaining the temperature at 71.5 ° C to 73.5 ° C to conduct crystallization, (4) Separation and extraction: draining the base solution that does not form a crystal, raising the temperature of the reactor back to 80 ° C to 90 ° C, and melting the crystal to give the final product from 4-cyanopyridine.
    It is preferably provided that in step (1) the purity of the 4-cyanopyridine crystal is 96.5% to 98.5%.
    It is preferably provided that in step (2) the cooling rate is 0.5 ° C./15 min to 1 ° C./15 min.
    It is preferably provided that the crystallization time in step (3) is 1 to 1.5 hours.
    It is preferably provided that in step (4) the purity of the end product of 4-cyanopyridine is> 99.0%.
    The present invention has the following advantageous effects: (1) The method for purifying 4-cyanopyridine by melt crystallization of the invention is characterized by a simple manufacturing process and thereby preventing a peritectic phenomenon by controlling the cooling rate during cooling for crystallization. (2) The high-purity 4-cyanopyridine produced according to the present invention has a high overall yield and purity.
    The purity is more than 99.0% and no by-product pollutants are generated.
    Thanks to multi-stage extraction, the comprehensive utilization rate of the raw materials exceeds 90%. DESCRIPTION OF THE INVENTION To better explain the exemplary embodiments according to the present invention or the configurations in the prior art, the accompanying drawings used in the exemplary embodiments are briefly described below, it being understood that the following drawings represent only some exemplary embodiments of the invention and are available to those of ordinary skill in the art In this area it is possible to obtain further drawings on the basis of such drawings without inventive activities.
    1 shows a gas chromatogram of the end product of 4-cyanopyridine obtained in a first embodiment, FIG. 2 shows a gas chromatogram of the end product of 4-cyanopyridine obtained in a first comparative example, FIG. 3 shows a gas chromatogram of the end product of 4-cyanopyridine obtained in a second embodiment, 4 shows a gas chromatogram of the end product of 4-cyanopyridine obtained in a second comparative example.
    Concrete Embodiments For a better understanding of the object, configuration and advantages of the present invention, the configurations of the exemplary embodiments according to the present invention are explained completely and clearly in such exemplary embodiments using the accompanying drawings, it being understood that the exemplary embodiments described are part of the exemplary embodiments of the present invention Represent invention instead of all exemplary embodiments. All other exemplary embodiments which are obtained by those skilled in the art using exemplary embodiments of the invention without inventive steps also belong to the scope of protection of the invention.
    First Embodiment A method for purifying 4-cyanopyridine by melt crystallization specifically comprises the following steps: (1) Melting 4-cyanopyridine: Introducing 4-cyanopyridine crystals with a purity of 96.5% into a reactor at normal pressure and setting the Temperature of the reactor to 82 ° C to cause the crystal to melt, (2) Cooling: regulating the temperature of the reactor and lowering the temperature of the molten 4-cyanopyridine according to a cooling rate of 0.5 ° C / 15 min to 72.5 ° C, (3) crystallization: maintaining the temperature at 72.5 ° C for a period of 0.5h to carry out the crystallization, (4) separation and extraction: draining the base solution that does not form a crystal, increasing the temperature of the Return reactor to 82 ° C and melt the crystal to obtain the final product of 4-cyanopyridine.
    When 4-cyanopyridine is purified by the method according to the first embodiment, an end product of 4-cyanopyridine is obtained with a primary yield of 37.8% and a purity of 99.06%. The gas chromatogram of the end product is shown in FIG.
    First Comparative Example A method for purifying 4-cyanopyridine by melt crystallization specifically comprises the following steps: (1) Melting 4-cyanopyridine: putting 4-cyanopyridine crystal with a purity of 96.8% in a reactor at normal pressure and adjusting the Temperature of the reactor to 85 ° C to cause the crystal to melt, (2) Cooling: regulating the temperature of the reactor and lowering the temperature of the molten 4-cyanopyridine to 71.0 according to a cooling rate of 0.5 ° C / 15 min ° C, (3) crystallization: maintaining the temperature at 71.0 ° C for a period of 1 hour to carry out crystallization, (4) separation and extraction: draining the base solution which does not form a crystal, raising the temperature of the reactor again to 85 ° C and melting the crystallization to obtain the final product of 4-cyanopyridine.
    When 4-cyanopyridine is purified by the method of the first comparative example, an end product of 4-cyanopyridine is obtained with a primary yield of 40.5% and a purity of 98.43%. The gas chromatogram of the end product is shown in FIG.
    Second exemplary embodiment A method for purifying 4-cyanopyridine by melt crystallization specifically comprises the following steps: (1) Melting 4-cyanopyridine: Placing 4-cyanopyridine crystals with a purity of 96.5% in a reactor at normal pressure and adjusting the Temperature of the reactor to 80 ° C to cause the crystal to melt, (2) cooling: regulating the temperature of the reactor and lowering the temperature of the molten 4-cyanopyridine to 72.8 at a cooling rate of 0.8 ° C / 15 min ° C, (3) crystallization: maintaining the temperature at 72.8 ° C for a period of 1 hour to carry out the crystallization, (4) separation and extraction: draining the base solution which does not form a crystal,
    Raise the temperature of the reactor back to 87 ° C and melt the crystallization to obtain the final product of 4-cyanopyridine.
    When 4-cyanopyridine is purified by the method according to the second embodiment, an end product of 4-cyanopyridine is obtained with a primary yield of 38.5% and a purity of 99.42%. The gas chromatogram of the end product is shown in FIG.
    Second Comparative Example A method for purifying 4-cyanopyridine by melt crystallization specifically comprises the following steps: (1) Melting 4-cyanopyridine: putting 4-cyanopyridine crystal with a purity of 96.8% in a reactor at normal pressure and adjusting the Temperature of the reactor to 85 ° C to cause the crystal to melt, (2) cooling: regulating the temperature of the reactor and lowering the temperature of the solution according to a cooling rate of 1.5 ° C / 15min to 71.5 ° C, (3) Crystallization: Maintaining the temperature at 71.5 ° C for 1 hour to carry out crystallization, (4) Separation and extraction: Draining the base solution which does not form a crystal, raising the temperature of the reactor back to 85 ° C and melting the crystallization to obtain the final product of 4-cyanopyridine.
    When 4-cyanopyridine is purified by the method according to the second comparative example, an end product of 4-cyanopyridine is obtained with a primary yield of 35.1% and a purity of 97.66%. The gas chromatogram of the end product is shown in FIG.
    The above exemplary embodiments only serve to illustrate the configuration of the present invention and are in no way intended to be restrictive. Although the present invention has been described in detail with reference to the above embodiments, it will be understood by those skilled in the art that various modifications to the equivalent substitutions of some of the features described in the previous embodiments are possible. However, such modifications or substitutions do not mean that the main ideas of the respective technical solutions deviate from the basic idea and the scope of the technical solutions of the embodiments of the present invention.
    权利要求:
    Claims (5)
    [1]
    1. A process for purifying 4-cyanopyridine by melt crystallization, characterized in that it comprises the following steps: (1) Melting 4-cyanopyridine: putting 4-cyanopyridine crystals into a reactor at normal pressure and adjusting the temperature of the reactor to 80 ° C to 90 ° C to cause the 4-cyanopyridine crystal to melt, (2) Cooling: regulating the temperature of the reactor and lowering the temperature of the molten 4-cyanopyridine to 71.5 ° C according to a certain cooling rate 73.5 ° C, (3) crystallization: maintaining the temperature at 71.5 ° C to 73.5 ° C to perform crystallization, (4) separation and extraction: draining the base solution not forming a crystal, increasing the Temperature the reactor back to 80 ° C to 90 ° C and melting the crystal to obtain the final product of 4-cyanopyridine.
    [2]
    2. A method for purifying 4-cyanopyridine by melt crystallization according to claim 1, characterized in that in step (1) the purity of the 4-cyanopyridine crystal is 96.5% to 98.5%.
    [3]
    3. A method for purifying 4-cyanopyridine by melt crystallization according to claim 1, characterized in that in step (2) the cooling rate is 0.5 ° C / 15 min to 1 ° C / 15 min.
    [4]
    4. A method for purifying 4-cyanopyridine by melt crystallization according to claim 1, characterized in that in step (3) the crystallization time is 1 to 1.5 hours.
    [5]
    5. A method for purifying 4-cyanopyridine by melt crystallization according to claim 1, characterized in that in step (4) the purity of the end product of 4-cyanopyridine is> 99.0%.
    类似技术:
    公开号 | 公开日 | 专利标题
    DE10242349B4|2007-08-23|Process for the separation of aromatics by extractive distillation and thereby used composite solvent
    BE1027319B1|2021-01-13|Process for the purification of 4-cyanopyridine by melt crystallization
    DE1257110B|1967-12-28|Process for separating helium or oxygen from a gas mixture
    DE3314395A1|1984-10-25|METHOD FOR CARRYING OUT CHEMICAL REACTIONS AND SIMULTANEOUSLY DISTILLATIVE DISASSEMBLY OF A PRODUCT MIXTURE IN MULTIPLE FRACTIONS BY MEANS OF A DISTILLATION COLUMN
    DE102011082513A1|2013-03-14|Plant for separating and concentrating a liquid component from a liquid multi-substance mixture
    EP0822245A2|1998-02-04|Process for obtaining pure aromatics from hydrocarbon mixtures containing aromatics and non-aromatics
    EP0329958A2|1989-08-30|Process for the preparation of an aromatic concentrate useful as a blending component for carburetion fuels
    EP2809310B1|2016-01-20|Process for the production of taxifolin from wood
    EP0434959B1|1995-01-18|Process for simultaneously obtaining purified benzene and purified toluene
    DE3319651A1|1984-12-06|METHOD FOR THE DISTILLATIVE PRODUCTION OF FORMIC ACID
    DE1695247C3|1975-05-28|Process for the purification of lactams by melt crystallization
    WO2006072360A1|2006-07-13|Method for the reduction of chlorine-containing components in organic isocyanates
    Hoffmann et al.1969|Über die γ-und δ-Modifikationen des Natriumdisilikates, Na2Si2O5
    DE4031967C1|1992-05-27|
    EP0505723B1|1995-08-02|Process for the separation of aromatics by extractive distillation
    DE102008023833B4|2013-03-21|Arrangement and method for producing high-purity crystals
    DE102007041803A1|2009-03-05|Process for producing polycrystalline silicon rods and polycrystalline silicon rod
    Markoff1935|Uber endlich-dimensionale Vektorraume
    DE2415041B2|1977-07-28|PROCEDURE FOR SEPARATING TWO COMPONENTS
    EP0109473A1|1984-05-30|Optical display element
    EP0418622A2|1991-03-27|Method for the separation of aromatics
    EP0864556B1|2001-03-28|Process for the production of high purity cyclopropylmethylketone
    DE3016335A1|1980-11-13|METHOD FOR PURIFYING ROHCAPROLACTAM
    DE19619018C2|1999-01-14|Single chamber coking system
    DE2659178C2|1979-03-15|Coupling arrangement, in particular for the connection of time division multiplex lines
    同族专利:
    公开号 | 公开日
    CN110272382A|2019-09-24|
    WO2021017649A1|2021-02-04|
    BE1027319A1|2021-01-05|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    CN106478498A|2016-09-23|2017-03-08|哈尔滨理工大学|Using chemical recrystallization and physical separation combine purification 4 cyanopyridines method|
    CN108997211A|2018-06-27|2018-12-14|中山大学|A kind of method of solvent crystallisation by cooling separation 4- cyanopyridine|
    GB815278A|1955-12-30|1959-06-24|Aries Associates Inc|Nitriles and amides of pyridine carboxylic acids|
    CN101602719B|2009-04-29|2011-06-15|南通醋酸化工股份有限公司|Synthesis method of 4-cyanopyridine|
    CN110272382A|2019-08-01|2019-09-24|安徽瑞邦生物科技有限公司|A kind of method of fusion-crystallization purification 4- cyanopyridine|
    CN110790702A|2019-11-11|2020-02-14|安徽瑞邦生物科技有限公司|Method for purifying 4-cyanopyridine by combining chemical recrystallization and physical separation|CN110272382A|2019-08-01|2019-09-24|安徽瑞邦生物科技有限公司|A kind of method of fusion-crystallization purification 4- cyanopyridine|
    法律状态:
    2021-03-19| FG| Patent granted|Effective date: 20210113 |
    优先权:
    申请号 | 申请日 | 专利标题
    CN201910706748.6A|CN110272382A|2019-08-01|2019-08-01|A kind of method of fusion-crystallization purification 4- cyanopyridine|
    [返回顶部]