CN112142582A - Synthetic method of methyl cyclopentenolone - Google Patents
Synthetic method of methyl cyclopentenolone Download PDFInfo
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Abstract
The invention relates to a preparation method of methyl cyclopentenolone, which comprises the following steps: (1) controlling the pH and temperature of a reaction system, and reacting dimethylamine hydrochloride, a formaldehyde aqueous solution and 2-methylfuran to generate N, N-dimethyl-5-methylfurfuryl amine; (2) when the monitored 2-methylfuran content is not reduced any more, adjusting the pH of the reaction solution to be less than 1 by using acid liquor, and reacting to obtain a product 1-dimethylamino-2, 5-hexanedione; (3) then adjusting the pH value of the reaction solution to 12-13 with alkali, extracting the reaction solution after reaction, concentrating and recovering the solvent, and rectifying to obtain a product 2- (dimethylamino) -3-methyl-2-cyclopentene-1-ketone; (4) mixing 2- (dimethylamino) -3-methyl-2-cyclopentene-1-ketone with hydrochloric acid, reacting, hydrolyzing, crystallizing, purifying to obtain methylcyclopentenol ketone, concentrating the reaction mother liquor, and recovering. Compared with the prior art, the invention is beneficial to realizing remote and automatic operation, reducing the treatment of waste water and reusing the raw material dimethylamine hydrochloride.
Description
Technical Field
The invention relates to the field of chemical synthesis, in particular to a synthetic method of methyl cyclopentenolone.
Background
Methylcyclopentenolone is also commonly known as MCP (methyl cyclopentenone), which is a natural substance present in maple, beechwood (fagaceae), tobacco and roasted coffee and appears as a white crystalline solid, and MCP is known as maple lactone because it has the outstanding sweet aroma of maple syrup, a strong pungent and sweet aroma and a sweet taste. MCP was originally extracted in 1912 from wood acetic acid dry distilled from beech trees by j.meyerfeld and was subsequently identified as MCP, of the formula:
there are also reports that mention may be made of the extraction of this material from the pyrolysis products of wood and carbohydrates. MCP is called maple lactone because MCP has the outstanding sweet aroma, strong pungent and sweet aroma and scorch and sweet taste of maple syrup. Besides the inherent fragrance, the sweet potato powder also has the functions of flavoring and sweetening, and is a good flavoring agent and low-heat sweetener. At present, MCP is widely used in food and beverage industry seasonings, medical use and tobacco and essence formulas at home and abroad.
The currently mainly adopted synthesis method for synthesizing MCP is as follows: (1) dimethyl oxalate method: mixing diethyl oxalate and dimethyl glutarate, heating and refluxing the mixture under the action of a catalyst, mixing the mixture with the dimethyl glutarate, heating the mixture for reaction, finally performing addition reaction by using potassium iodide, and decarboxylating the mixture by using 42% phosphoric acid solution to obtain MCP. (2) Adipic acid dimethyl ester method: firstly, adipic acid and methanol or ethanol are utilized to prepare adipic acid diester, and the adipic acid diester is subjected to Dieckmann reaction to obtain cyclopentyl-2-keto ester. Reacting with a methylating agent under an alkaline condition to obtain the 2-methylcyclopentan-2-keto ester. And finally, MCP is prepared through chlorination, hydrolysis and decarboxylation, but the requirement on temperature control is high in the reaction process, a large amount of chlorine is generated when a solvent is recovered, the reaction risk is improved, a large amount of water and alkali liquor are needed for neutralization and abandonment, a large amount of waste water is generated, and the waste gas recovery cost is increased.
The chemical reaction equations for the two synthetic methods are as follows:
disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a synthetic method of methylcyclopentadienolone which is beneficial to realizing remote and automatic operation, reducing the treatment of waste water and reusing the raw material dimethylamine hydrochloride.
The purpose of the invention can be realized by the following technical scheme:
a synthetic method of methyl cyclopentenolone comprises the following steps:
(1) controlling the pH and temperature of a reaction system, and reacting dimethylamine hydrochloride, a formaldehyde aqueous solution and 2-methylfuran to generate N, N-dimethyl-5-methylfurfuryl amine;
(2) when the monitored 2-methylfuran content is not reduced any more, adjusting the pH of the reaction solution to be less than 1 by using acid liquor, and reacting to obtain a product 1-dimethylamino-2, 5-hexanedione; the acid solution is industrial hydrochloric acid with the concentration of 5-37 wt%, preferably 30.0 wt%;
(3) then adjusting the pH value of the reaction solution to 12-13 with alkali, extracting the reaction solution after reaction, concentrating and recovering the solvent, and rectifying to obtain a product 2- (dimethylamino) -3-methyl-2-cyclopentene-1-ketone; the 2-methylfuran content is determined by quantitative analysis using an on-line infrared instrument. The alkaline solution is sodium hydroxide solution with concentration of 5-40 wt%, preferably 30.0 wt%.
(4) Mixing 2- (dimethylamino) -3-methyl-2-cyclopentene-1-ketone with hydrochloric acid, reacting, hydrolyzing, crystallizing, purifying to obtain Methyl Cyclopentenolone (MCP), concentrating the reaction mother liquor, and recovering. Concentrating the reaction mother liquor, recovering a small amount of MCP dissolved in the mother liquor, and recovering dimethylamine hydrochloride in the mother liquor to be used as a raw material for reaction again for recycling, wherein the reaction formula is as follows:
further, the dimethylamine hydrochloride was replaced with the recovery reaction mother liquor containing dimethylamine hydrochloride in step (4). The content of dimethylamine hydrochloride in the recovered reaction mother liquor is determined by quantitative analysis by an on-line infrared instrument.
Further, the molar ratio of dimethylamine hydrochloride to formaldehyde is (1-1.2): 1. Preferably (1-1.02): 1. The mass concentration of the formaldehyde aqueous solution is 37-40 omega t%.
Further, the molar ratio of dimethylamine hydrochloride to 2-methylfuran is (1-1.3): 1. Preferably (1.05-1.07): 1.
Further, in the step (1), when the mass content of the 2-methylfuran is less than 0.55%, the content is considered not to be reduced.
Further, in the step (4), the molar ratio of the 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one to HCl is (0.7-1):1, preferably (0.8-0.83): 1. The hydrochloric acid is industrial hydrochloric acid with the concentration of 20-37 omega t%, preferably 30-37 omega t%.
Further, the pH described in step (1) is 2-7, preferably 3-6; the temperature is 45-70 deg.C, preferably 50-65 deg.C.
Further, the reaction in step (2) is carried out at a temperature of 60-100 ℃, preferably 70-100 ℃ for 1-4h, preferably 2-3 h.
Further, the reaction temperature of the reaction in the step (3) is 70-75 ℃, and the time is 0.4-0.6 h.
Further, the reaction in step (4) is carried out at a temperature of 60-100 ℃, preferably 70-100 ℃ for 1-4h, preferably 2-3 h.
Compared with the prior art, the invention has the following advantages:
(1) the content of the 2-methylfuran in the system is controlled, so that the synthesized N, N-dimethyl-5-methylfurfurylamine can be directly used for synthesizing 2- (dimethylamino) -3-methyl-2-cyclopentene-1-one without separation, and the N, N-dimethyl-5-methylfurfurylamine does not need to be separated and purified and then subjected to the next reaction like the prior art, thereby reducing the treatment of waste water and simplifying the operation process;
(2) concentrating the reaction mother liquor, recovering a small amount of MCP dissolved in the mother liquor, and recovering dimethylamine hydrochloride in the mother liquor to be used as a raw material for reaction again for recycling, thereby achieving the dual purposes of three-waste treatment and energy conservation and emission reduction;
(3) the on-line analysis can visually track the reaction process, and the next operation can be performed in time according to the reaction process, thereby being beneficial to realizing remote and automatic operation.
Detailed Description
The following examples are given for the detailed implementation and specific operation of the present invention, but the scope of the present invention is not limited to the following examples.
A synthetic method of methyl cyclopentenolone comprises the following steps:
(1) controlling the reaction system at pH 2-7, preferably pH 3-6, and at 45-70 deg.C, preferably 50-65 deg.C, and monitoring the reaction process of dimethylamine hydrochloride, formaldehyde water solution and 2-methylfuran to produce N, N-dimethyl-5-methylfurfurylamine by an on-line infrared instrument; wherein the molar ratio of dimethylamine hydrochloride to formaldehyde is (1-1.2) to 1, preferably (1-1.02) to 1; the mass concentration of the formaldehyde aqueous solution is 37-40 omega t%; the molar ratio of dimethylamine hydrochloride to 2-methylfuran is (1-1.3): 1. Preferably (1.05-1.07): 1.
Detecting the content of 2-methylfuran in the reaction liquid to be less than 0.55%, then acidifying the reaction system with industrial hydrochloric acid with the pH of less than 1 at the concentration of 5-37 w t%, preferably 30 w t%, at 60-100 ℃, preferably 70-100 ℃, for 1-4h, preferably 2-3h to obtain the product 1-dimethylamino-2, 5-hexanedione, then adjusting the pH of the reaction liquid to 12-13 with sodium hydroxide solution with the concentration of 5-40 w t%, preferably 30.0 w t%, reacting at 70-75 ℃ for 0.4-0.6h, preferably 0.5h, extracting the reaction liquid, concentrating and recovering the solvent, rectifying and recovering the front fraction and the rear fraction 2- (dimethylamino) -3-methyl-2-cyclopentene-1-one;
(2)2- (dimethylamino) -3-methyl-2-cyclopenten-1-one is hydrolyzed for 1 to 4 hours, preferably 2 to 3 hours, at the temperature of 60 to 100 ℃, preferably 70 to 100 ℃ by adding hydrochloric acid, the solution is adjusted to the strong acid condition, the solution is crystallized to obtain MCP crude product, then the mother solution is concentrated and crystallized to recover a small amount of MCP crude product, wherein the molar ratio of the 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one to HCl is (0.7 to 1):1, preferably (0.8 to 0.83):1, and the hydrochloric acid is industrial hydrochloric acid with the concentration of 20 to 37 omega t%, preferably 30 to 37 omega t%.
And (3) measuring the content of dimethylamine hydrochloride in the recovered mother liquor by using an online infrared instrument, reacting the recovered mother liquor with an aqueous formaldehyde solution and 2-methylfuran at the pH value of 2-7, preferably the pH value of 3-6, at the temperature of 45-70 ℃, preferably 50-65 ℃ to generate N, N-dimethyl-5-methylfurfuryl amine, and repeating the step (1) to continuously use the recovered mother liquor for MCP synthesis.
Example 1
A synthetic method of methyl cyclopentenolone comprises the following steps:
(1) adding 44.85g (0.55mol) of dimethylamine hydrochloride and 19.59g (1.09mol) of water into a 500ml four-neck flask, controlling the temperature to 50 ℃, adding 42.08g (37-40%, 0.54mol) of formaldehyde, adjusting the pH of a reaction solution to 4.5, and beginning to dropwise add 42.69g (0.52mol) of 2-methylfuran after reacting for 0.5 h;
using React IRTM15 monitoring the reaction solution to find the content of 2-methylfuran<0.55 percent and the mass content of the N, N-dimethyl-5-methylfurfurylamine is 46.24 percent, then dilute hydrochloric acid is added to adjust the pH to 0.95, the temperature is raised to 70 ℃, after 3 hours of reaction, the pH is adjusted to 12.5 by sodium hydroxide solution, the temperature is controlled to 75-80 ℃, the reaction is carried out for 0.5 hour, the content of the 2- (dimethylamino) -3-methyl-2-cyclopentene-1-ketone is measured to be 95.57 percent, the solvent is recovered by extraction and concentration, 2.24g of front fraction is collected after rectification, wherein the N, N-dimethyl-5-methylfurfurylamine (95.36 percent), the 2- (dimethylamino) -3-methyl-2-cyclopentene-1-ketone (4.64 percent), and the rear fraction of the 2- (dimethylamino) -3-methyl-2-cyclopentene-1-ketone is 64.72g (99.62 percent), the final yield of the product was 93.96%.
(2) Adding 55g (0.4mol) of 2- (dimethylamino) -3-methyl-2-cyclopentene-1-one and 17.93g (1.0mol) of water into a 250ml flask, dripping 47.35g (0.48mol) of hydrochloric acid, reacting for 2-3h at 70 ℃, cooling to 10-15 ℃ in a grading way, filtering, washing with water to obtain 33.26g of MCP crude product and 85.14g of mother liquor a; concentrating the mother liquor a, crystallizing, filtering to obtain small amount of MCP crude product 3.25g and mother liquor b35.05g, recrystallizing the MCP crude product, and obtaining MCP pure product 35.84g (99.73%), wherein the final yield of MCP is 79.69%, and the React IR is utilizedTM15 the content of dimethylamine hydrochloride in the mother liquor b was 69.81%, and the recovery of dimethylamine hydrochloride was 75.02%.
A250 ml four-necked flask was charged with 35.05g (0.30mol) of mother liquor b and 23.38g (37-40%, 0.30mol) of formaldehyde to adjust the pH of the reaction mixture to 4.5, reacted at 50 ℃ for 0.5 hour, and then 22.99g (0.28mol) of 2-methylfuran was added dropwise thereto using React IRTM15 monitoring the reaction solution to find the content of 2-methylfuran<0.55% and the content of N, N-dimethyl-5-methylfurfuryl amine is 45.21%, dissolved in sodium hydroxideAdjusting the pH value to 12.5, extracting, concentrating and recovering the solvent, rectifying, and collecting 36.90g (99.67%) of the product N, N-dimethyl-5-methylfurfuryl amine with the yield of 94.38%. Indicating that the mother liquor b can be completely recycled and continuously used for the synthesis of MCP.
Example 2
A synthetic method of methyl cyclopentenolone comprises the following steps:
(1) a500 ml four-neck flask was charged with 44.85g (0.55mol) of dimethylamine hydrochloride and 19.59g (1.09mol) of water, the temperature was controlled to 60 ℃, 42.08g (37-40%, 0.54mol) of formaldehyde was added, the pH of the reaction solution was adjusted to 4.5, after 0.5 hour of the reaction, 42.69g (0.52mol) of 2-methylfuran was added dropwise,
using React IRTM15 monitoring the reaction solution to find the content of 2-methylfuran<0.55 percent and the content of N, N-dimethyl-5-methylfurfuryl amine is 48.27 percent, then dilute hydrochloric acid is added to adjust the pH value to 0.95, the temperature is increased to 80 ℃, after 3 hours of reaction, the pH value is adjusted to 12.5 by sodium hydroxide solution, the temperature is controlled to 75-80 ℃, the reaction is carried out for 0.5 hour, the content of 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one is measured to be 95.61 percent, the solvent is recovered by extraction and concentration, 2.21g of front cut fraction is collected after rectification, wherein N, N-dimethyl-5-methylfurfuryl amine (96.21 percent), 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one (3.79 percent), and the front cut fraction is 67.68g (99.69 percent) of 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one, the final yield of the product was 94.07%.
(2) Adding 55g (0.40mol) of 2- (dimethylamino) -3-methyl-2-cyclopentene-1-one and 17.93g (1.00mol) of water into a 250ml flask, dripping 47.35g (0.48mol) of hydrochloric acid, reacting for 2-3h at 80 ℃, cooling to 10-15 ℃ in a grading way, filtering, and washing with water to obtain 36.89g of MCP crude product and 90.03g of mother liquor a; concentrating the mother liquor a, crystallizing, filtering to obtain small amount of crude MCP product 3.04g and mother liquor b 39.72g, recrystallizing the crude MCP product to obtain pure MCP product 37.74g (99.87%), wherein the final yield of MCP is 84.04%, and utilizing React IR to obtain the final productTM15 the content of dimethylamine hydrochloride in the mother liquor b was 69.81%, and the recovery of dimethylamine hydrochloride was 85.01%.
A250 ml four-necked flask was charged with 39.72g (0.34mol) of the mother liquor b and 26.49g (37 to 40%, 0.34mol) of formaldehyde, the pH of the reaction mixture was adjusted to 4.5, the mixture was reacted at 60 ℃ for 0.5 hour, and 2-methyl was added dropwise theretoFuran 25.45g (0.31mol), using React IRTM15 monitoring the reaction solution to find the content of 2-methylfuran<0.55 percent and the content of the N, N-dimethyl-5-methylfurfuryl amine is 46.72 percent, the pH value is adjusted to 12.5 by sodium hydroxide solution, the solvent is extracted, concentrated and recovered, and after rectification, 42.20g (99.59 percent) of the product N, N-dimethyl-5-methylfurfuryl amine is collected, and the yield of the product is 97.40 percent. Indicating that the mother liquor b can be completely recycled and continuously used for the synthesis of MCP.
Example 3
A synthetic method of methyl cyclopentenolone comprises the following steps:
(1) a500 ml four-neck flask is added with 44.85g (0.55mol) of dimethylamine hydrochloride and 19.59g (1.09mol) of water, the temperature is controlled to 65 ℃, 42.08g (37-40%, 0.54mol) of formaldehyde is added, the pH value of the reaction solution is adjusted to 4.5, 42.69g (0.52mol) of 2-methylfuran is added dropwise after 0.5h of reaction,
using React IRTM15 monitoring the reaction to find the 2-methylfuran content<0.55 percent of N, N-dimethyl-5-methylfurfurylamine, the content of which is 45.77 percent, then dilute hydrochloric acid is added, the pH value is adjusted to 0.95, the temperature is increased to 90 ℃, after the reaction is carried out for 2 to 3 hours, the pH value is adjusted to 12.5 by sodium hydroxide solution, the temperature is controlled to 75 to 80 ℃, the reaction is carried out for 0.5 hour, the content of 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one is measured to be 95.61 percent, the solvent is recovered by extraction and concentration, a front fraction of 2.20g is collected after rectification, wherein, the N, N-dimethyl-5-methylfurfurylamine (96.02 percent), the 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one (3.98 percent), the rear fraction of 63.94g (99.81 percent) of 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one, the final yield of the product was 93.75%.
(2) Adding 55g (0.40mol) of 2- (dimethylamino) -3-methyl-2-cyclopentene-1-one and 17.93g (1.00mol) of water into a 250ml flask, dripping 47.35g (0.48mol) of hydrochloric acid, reacting for 2-3h at 90 ℃, cooling to 10-15 ℃ in a grading way, filtering, washing with water to obtain 39.31g of MCP crude product and 91.98g of mother liquor; concentrating the mother liquor a, crystallizing, filtering to obtain small amount of crude MCP 2.24g and mother liquor b 40.88g, recrystallizing the crude MCP to obtain purified MCP 39.14g (99.74%), wherein the final yield of MCP is 87.05%, and the method utilizes React IR to extract MCPTM15 the content of dimethylamine hydrochloride in the quantitative mother liquor b is 69.82 percent, and the recovery rate of the dimethylamine hydrochloride is 87.49 percent。
A250 ml four-necked flask was charged with 40.88g (0.35mol) of mother liquor and 27.27g (37-40%, 0.35mol) of formaldehyde, the pH of the reaction mixture was adjusted to 4.5, the mixture was reacted at 65 ℃ for 0.5 hour, 26.27g (0.32mol) of 2-methylfuran was added dropwise thereto, and the mixture was subjected to reaction IRTM15 monitoring the reaction to find the 2-methylfuran content<0.55 percent and the content of the N, N-dimethyl-5-methylfurfuryl amine is 47.17 percent, the pH value is adjusted to 12.5 by sodium hydroxide solution, the solvent is extracted, concentrated and recovered, and after rectification, 40.35g (99.72 percent) of the product N, N-dimethyl-5-methylfurfuryl amine is collected, and the yield of the product is 90.33 percent. Indicating that the mother liquor b can be completely recycled and continuously used for the synthesis of MCP.
Example 4
A synthetic method of methyl cyclopentenolone comprises the following steps:
(1) adding 44.85g (0.55mol) of dimethylamine hydrochloride and 19.59g (1.09mol) of water into a 500ml four-neck flask, controlling the temperature to be 60 ℃, adding 42.08g (37-40%, 0.54mol) of formaldehyde, adjusting the pH of a reaction solution to be 3, and beginning to dropwise add 42.69g (0.52mol) of 2-methylfuran after reacting for 0.5 h;
using React IRTM15 monitoring the reaction to find the 2-methylfuran content<0.55 percent and the content of N, N-dimethyl-5-methylfurfuryl amine is 45.29 percent, then dilute hydrochloric acid is added to adjust the pH value to 0.95, the temperature is raised to 100 ℃, after 2 to 3 hours of reaction, the pH value is adjusted to 12.5 by sodium hydroxide solution, the temperature is controlled to 75 to 80 ℃, the reaction is carried out for 0.5 hour, the content of 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one is measured to be 95.62 percent, the solvent is recovered by extraction and concentration, 2.03g of front cut fraction is collected after rectification, wherein, N-dimethyl-5-methylfurfuryl amine (95.89 percent), 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one (4.11 percent), the product 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one is 63.23g (99.75 percent), the final yield of the product was 93.71%.
(2) Adding 55g (0.40mol) of 2- (dimethylamino) -3-methyl-2-cyclopentene-1-one and 17.93g (1.0mol) of water into a 250ml flask, dripping 47.35g (0.48mol) of hydrochloric acid, reacting for 2-3h at 100 ℃, cooling to 10-15 ℃ in a grading way, filtering, washing with water to obtain 42.77g of MCP crude product and 95.93g of mother liquor a; concentrating the mother liquor a, crystallizing, filtering to obtain small amount of MCP crude product 3.15g and mother liquor b 45.55g, recrystallizing the MCP crude product43.83g (99.88%) of MCP pure product, the final yield of MCP is 97.61%, and the React IR is utilizedTM15 quantitative mother liquor b contained 69.79% of dimethylamine hydrochloride, and the recovery of dimethylamine hydrochloride was 97.33%.
A250 ml four-necked flask was charged with 45.55g (0.39mol) of mother liquor b and 30.39g (37-40%, 0.39mol) of formaldehyde to adjust the pH of the reaction mixture to 2-3, reacted at 60 ℃ for 0.5 hour, then added dropwise with 29.56g (0.36mol) of 2-methylfuran, and the reaction mixture was subjected to React IRTM15 monitoring the reaction solution to find the content of 2-methylfuran<0.55 percent and the content of the N, N-dimethyl-5-methylfurfuryl amine is 47.50 percent, the pH value is adjusted to 12.5 by sodium hydroxide solution, the solvent is extracted, concentrated and recovered, after rectification, 46.17g (99.62 percent) of the product N, N-dimethyl-5-methylfurfuryl amine is collected, and the yield of the product is 91.76 percent. Indicating that the mother liquor b can be completely recycled and continuously used for the synthesis of MCP.
Example 5
A synthetic method of methyl cyclopentenolone comprises the following steps:
(1) adding 44.85g (0.55mol) of dimethylamine hydrochloride and 19.59g (1.09mol) of water into a 500ml four-neck flask, controlling the temperature to be 60 ℃, adding 42.08g (37-40%, 0.54mol) of formaldehyde, adjusting the pH of a reaction solution to be 6, and beginning to dropwise add 42.69g (0.52mol) of 2-methylfuran after reacting for 0.5 h;
using React IRTM15 monitoring the reaction to find the 2-methylfuran content<0.55 percent and the content of the N, N-dimethyl-5-methylfurfuryl amine is 44.32 percent, then dilute hydrochloric acid is added to adjust the pH value to 0.95, the temperature is raised to 100 ℃, after 2 to 3 hours of reaction, the pH value is adjusted to 12.5 by sodium hydroxide solution, the reaction is carried out for 0.5 hour under the temperature controlled to 75 to 80 ℃, the content of the 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one is measured to be 95.71 percent, the solvent is recovered by extraction and concentration, 2.07g of front fraction is collected after rectification, wherein, the N, N-dimethyl-5-methylfurfuryl amine (94.98 percent), the 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one (5.02 percent), and 62.07g of the rear fraction of the 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one (99.57, 99 percent, the final yield of the product was 94.01%.
(2) A250 ml flask was charged with 55g (0.40mol) of 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one and 17.93g (0.10mol) of water, 47.35g (0.48mol) of hydrochloric acid was added dropwise, reacted at 100 ℃ for 2 to 3 hours, and then fractionatedCooling to 10-15 ℃, filtering, and washing with water to obtain 42.69g of MCP crude product and 95.74g of mother liquor a; concentrating the mother liquor a, crystallizing, filtering to obtain small amount of crude MCP 2.89g and mother liquor b 45.56g, recrystallizing the crude MCP to obtain pure MCP 43.90g (99.57%), and obtaining final MCP yield of 97.46% by using React IRTM15 quantitative mother liquor b contained 69.80% of dimethylamine hydrochloride, and the recovery of dimethylamine hydrochloride was 97.49%.
A250 ml four-necked flask was charged with 45.56g (0.39mol) of mother liquor and 29.61g (37-40%, 0.38mol) of formaldehyde, the pH of the reaction mixture was adjusted to 6, the mixture was reacted at 60 ℃ for 0.5 hour, 30.38g (0.37mol) of 2-methylfuran was added dropwise thereto, and the mixture was subjected to reaction IRTM15 monitoring the reaction solution to find the content of 2-methylfuran<0.55 percent and the content of the N, N-dimethyl-5-methylfurfuryl amine is 50.11 percent, the pH value is adjusted to 12.5 by sodium hydroxide solution, the solvent is extracted, concentrated and recovered, and after rectification, 47.85g (99.77 percent) of the product N, N-dimethyl-5-methylfurfuryl amine is collected, and the yield of the product is 90.27 percent. Indicating that the mother liquor b can be completely recycled and continuously used for the synthesis of MCP.
Example 6
A synthetic method of methyl cyclopentenolone comprises the following steps:
(1) a 500ml four-neck flask is added with 45.56g (0.39mol) of the mother liquor b in example 5, then 13.05g (0.16mol) of dimethylamine hydrochloride and 5.83g of water are added, the temperature is controlled to 60 ℃, 42.08g (37-40%, 0.54mol) of formaldehyde is added, the pH of the reaction solution is adjusted to 4.5, and 42.69g (0.52mol) of 2-methylfuran is added dropwise after 0.5h of reaction;
using React IRTM15 monitoring the reaction solution to find the content of 2-methylfuran<0.55 percent and the content of N, N-dimethyl-5-methylfurfurylamine is 48.37 percent, then dilute hydrochloric acid is added to adjust the pH to 0.95, the temperature is raised to 70 ℃, after 2 to 3 hours of reaction, the pH is adjusted to 12.3 by sodium hydroxide solution, after 0.5 hour of reaction under the temperature of 75 to 80 ℃, the content of 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one is 85.45 percent, after extraction, solvent recovery by concentration and rectification, 9.38g of front cut fraction is collected, wherein N, N-dimethyl-5-methylfurfurylamine (96.61 percent), 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one (3.39 percent), and 60.11g (99.68 percent) of rear cut fraction 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one are collected, the product is the mostThe final yield was 83.47%.
(2) Adding 55g (0.40mol) of 2- (dimethylamino) -3-methyl-2-cyclopentene-1-one and 17.93g (1.00mol) of water into a 250ml flask, dripping 47.35g (0.48mol) of hydrochloric acid, reacting for 2-3h at 100 ℃, cooling to 10-15 ℃ in a grading way, filtering, and washing with water to obtain 43.12g of MCP crude product and 95.23g of mother liquor a; concentrating the mother liquor a, crystallizing, filtering to obtain small amount of crude MCP product 3.01g and mother liquor b 45.75g, recrystallizing the crude MCP product to obtain pure MCP product 43.77g (99.62%), obtaining MCP yield 97.22%, and utilizing React IR to collect MCPTM15% of the mother liquor b was 69.60% dimethylamine hydrochloride.
Example 7
A synthetic method of methyl cyclopentenolone comprises the following steps:
(1) adding 44.85g (0.55mol) of dimethylamine hydrochloride and 19.59g (1.09mol) of water into a 500ml four-neck flask, controlling the temperature to be 60 ℃, adding 42.08g (37-40%, 0.54mol) of formaldehyde, adjusting the pH of a reaction solution to be 4.5, and beginning to dropwise add 42.69g (0.52mol) of 2-methylfuran after reacting for 0.5 h;
using React IRTM15 monitoring the reaction solution to find the content of 2-methylfuran<0.55 percent and the content of N, N-dimethyl-5-methylfurfurylamine is 48.31 percent, then dilute hydrochloric acid is added to adjust the pH value to 0.95, the temperature is raised to 80 ℃, after 2 to 3 hours of reaction, the pH value is adjusted to 12.3 by sodium hydroxide solution, the content of 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one is 89.87 percent after 0.5 hour of reaction and the temperature is controlled to 75 to 80 ℃, the solvent is recovered by extraction and concentration, a front fraction of 6.99g is collected after rectification, wherein, N-dimethyl-5-methylfurfurylamine (95.73 percent), 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one (4.27 percent), a rear fraction of 63.41g (99.68 percent) of 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one are extracted, the final yield of the product was 88.11%.
(2) Adding 55g (0.40mol) of 2- (dimethylamino) -3-methyl-2-cyclopentene-1-one and 17.93g (1.00mol) of water into a 250ml flask, dripping 47.35g (0.48mol) of hydrochloric acid, reacting for 2-3h at 100 ℃, cooling to 10-15 ℃ in a grading way, filtering, and washing with water to obtain 43.04g of MCP crude product and 94.89g of mother liquor a; concentrating the mother liquor a, crystallizing, filtering to obtain small amount of MCP crude product 2.43g and mother liquor b 45.89g, recrystallizing the MCP crude product, and obtaining MCP pure product 44.16g (99.59%) MCP final yield of 98.06% using React IRTM15% of the mother liquor b was 69.60% dimethylamine hydrochloride.
Example 8
A synthetic method of methyl cyclopentenolone comprises the following steps:
(1) in a 500ml four-necked flask, 44.85g (0.55mol) of dimethylamine hydrochloride and 19.59g (1.09mol) of water were charged, the temperature was controlled to 60 ℃, 42.08g (37-40%, 0.54mol) of formaldehyde was added, the pH of the reaction mixture was adjusted to 4.5, and after 0.5 hour of the reaction, 42.69g (0.52mol) of 2-methylfuran was added dropwise.
Using React IRTM15 monitoring the reaction solution to find the content of 2-methylfuran<0.55 percent and the content of N, N-dimethyl-5-methylfurfuryl amine is 48.37 percent, then dilute hydrochloric acid is added to adjust the pH to 0.95, the temperature is raised to 90 ℃, after 2 to 3 hours of reaction, the pH is adjusted to 12.3 by sodium hydroxide solution, after 0.5 hour of reaction under the temperature of 75 to 80 ℃, the content of 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one is 92.68 percent, after extraction, solvent recovery by concentration and rectification, 5.06g of front cut fraction is collected, wherein N, N-dimethyl-5-methylfurfuryl amine (94.71 percent), 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one (5.29 percent), the product 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one 65.06g (99.68 percent), the final yield of the product was 90.22%.
(2) Adding 55g (0.40mol) of 2- (dimethylamino) -3-methyl-2-cyclopentene-1-one and 17.93g (1.00mol) of water into a 250ml flask, dripping 47.35g (0.48mol) of hydrochloric acid, reacting for 2-3h at 100 ℃, cooling to 10-15 ℃ in a grading way, filtering, and washing with water to obtain 42.91g of MCP crude product and 95.38g of mother liquor a; concentrating the mother liquor a, crystallizing, filtering to obtain small amount of crude MCP 2.87g and mother liquor b 45.45g, recrystallizing the crude MCP to obtain pure MCP 44.05g (99.66%), obtaining MCP yield 97.89%, and using React IR to collect MCPTM15% of the mother liquor b was 69.59% dimethylamine hydrochloride.
Example 9
(1) From examples 6 to 8, 64.44g of mother liquor b (dimethylamine hydrochloride: 0.55mol) was charged in a 500ml four-necked flask, the temperature was controlled to 60 ℃, 42.08g (37 to 40%, 0.54mol) of formaldehyde was added, the pH of the reaction mixture was adjusted to 4.5, and after 0.5 hour of the reaction, 42.69g (0.52mol) of 2-methylfuran was added dropwise.
Using React IRTM15 monitoring the reaction solution to find the content of 2-methylfuran<0.55 percent of N, N-dimethyl-5-methylfurfurylamine, the content of which is 48.33 percent, then dilute hydrochloric acid is added, the pH value is adjusted to 0.95, the temperature is increased to 100 ℃, after the reaction is carried out for 2 to 3 hours, the pH value is adjusted to 12.3 by sodium hydroxide solution, after the reaction is carried out for 0.5 hour under the condition of controlling the temperature to be 75 to 80 ℃, the content of 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one is 95.63 percent, the solvent is recovered by extraction and concentration, 2.15g of front cut fraction is collected after rectification, wherein N, N-dimethyl-5-methylfurfurylamine (94.71 percent), 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one (5.29 percent), the product of 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one (67.69 g (99.82 percent), the final yield of the product was 93.86%.
(2) Adding 55g (0.40mol) of 2- (dimethylamino) -3-methyl-2-cyclopentene-1-one and 17.93g (1.00mol) of water into a 250ml flask, dripping 47.35g (0.48mol) of hydrochloric acid, reacting for 2-3h at 100 ℃, cooling to 10-15 ℃ in a grading way, filtering, and washing with water to obtain 42.79g of MCP crude product and 95.42g of mother liquor a; the mother liquor a is concentrated, crystallized and filtered to obtain a small amount of crude MCP (2.22 g) and mother liquor b (45.63 g), the crude MCP is recrystallized to obtain pure MCP (43.92 g, 99.72%), and the final yield of MCP is 97.66%.
Example 10
A synthetic method of methyl cyclopentenolone comprises the following steps:
(1) 32.60g of the fore-cut recovered in examples 1 to 8, in which N, N-dimethyl-5-methylfurfurylamine (95.83%, 0.22mol), 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one (4.17 mol) and 49.17g (2.73mol) of water were added to a 250ml four-necked flask, the reaction solution was adjusted to pH 0.95 with dilute hydrochloric acid, heated to 100 ℃ and reacted for 2 to 3 hours, adjusted to pH 12.5 with sodium hydroxide solution, controlled to 75 to 80 ℃ and reacted for 0.5 hour, the content of 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one was determined to be 95.71%, the solvent was recovered by extraction and concentration, and 1.44g of the fore-cut was collected after rectification, N, N-dimethyl-5-methylfurfurylamine (94.92%), 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one (8.08%), and the latter fraction 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one 30.63g (99.52%), yielding 93.60%.
(2) 30g (0.22mol) of 2- (dimethylamino) -3-methyl-2-cyclopentene-1-one and 15.34g (0.85mol) of water are added into a 250ml flask, 25.65g (0.26mol) of hydrochloric acid is dripped into the flask, after the mixture reacts for 2 to 3 hours at the temperature of 100 ℃, the temperature is reduced to 10 to 15 ℃ in a grading way, the mixture is filtered and washed by water to obtain 23.57g of MCP crude product and 54.68g of mother liquor a; the mother liquor a is concentrated, crystallized and filtered to obtain a small amount of crude MCP (1.62 g) and mother liquor b (25.17 g), the crude MCP is recrystallized to obtain pure MCP (24.21 g, 99.53%), and the final yield of MCP is 97.67%.
The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.
Claims (10)
1. A synthetic method of methyl cyclopentenolone is characterized by comprising the following steps:
(1) controlling the pH and temperature of a reaction system, and reacting dimethylamine hydrochloride, a formaldehyde aqueous solution and 2-methylfuran to generate N, N-dimethyl-5-methylfurfuryl amine;
(2) when the monitored 2-methylfuran content is not reduced any more, adjusting the pH of the reaction solution to be less than 1 by using acid liquor, and reacting to obtain a product 1-dimethylamino-2, 5-hexanedione;
(3) then adjusting the pH value of the reaction solution to 12-13 with alkali, extracting the reaction solution after reaction, concentrating and recovering the solvent, and rectifying to obtain a product 2- (dimethylamino) -3-methyl-2-cyclopentene-1-ketone;
(4) mixing 2- (dimethylamino) -3-methyl-2-cyclopentene-1-ketone with hydrochloric acid, reacting, hydrolyzing, crystallizing, purifying to obtain methylcyclopentenol ketone, concentrating the reaction mother liquor, and recovering.
2. The method of synthesizing methylcyclopentenolone according to claim 1, wherein said dimethylamine hydrochloride is replaced with the recovery reaction mother liquor containing dimethylamine hydrochloride in step (4).
3. The method for synthesizing methylcyclopentenone according to claim 1 or 2, wherein the molar ratio of dimethylamine hydrochloride to formaldehyde is (1-1.2): 1.
4. The method for synthesizing methylcyclopentenol ketone according to claim 1 or 2, wherein the molar ratio of dimethylamine hydrochloride to 2-methylfuran is (1-1.3): 1.
5. The method for synthesizing methylcyclopentenol ketone according to claim 1 or 2, wherein in step (1), when the mass content of 2-methylfuran is less than 0.55%, the content is considered not to decrease.
6. The method for synthesizing methylcyclopentenol ketone according to claim 1 or 2, wherein in step (4), the molar ratio of 2- (dimethylamino) -3-methyl-2-cyclopenten-1-one to HCl is (0.7-1): 1.
7. The method for synthesizing methylcyclopentenol ketone according to claim 1 or 2, wherein the pH in step (1) is 2-7; the temperature is 45-70 ℃.
8. The method for synthesizing methylcyclopentenol ketone according to claim 1 or 2, wherein the reaction temperature in step (2) is 60-100 ℃ and the reaction time is 1-4 h.
9. The method for synthesizing methylcyclopentenol ketone according to claim 1 or 2, wherein the reaction temperature in step (3) is 70-75 ℃ and the reaction time is 0.4-0.6 h.
10. The method for synthesizing methylcyclopentenol ketone according to claim 1 or 2, wherein the reaction temperature in step (4) is 60-100 ℃ and the reaction time is 1-4 h.
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Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58210041A (en) * | 1982-06-02 | 1983-12-07 | Sanyo Chem Ind Ltd | Production of 2-hydroxy-3-alkyl-2-cyclopenten-1-one |
| CN1100406A (en) * | 1993-06-03 | 1995-03-22 | 住友化学工业株式会社 | A process for the production of a cyclopentenol derivative |
| CN103113246A (en) * | 2012-11-11 | 2013-05-22 | 安徽金禾实业股份有限公司 | Production method of methyl cyclopentenolone via amination and step-by-step reaction |
| CN104370725A (en) * | 2014-09-27 | 2015-02-25 | 安徽金禾实业股份有限公司 | Methyl cyclopentenolone (MCP) rearrangement optimizing production method |
| CN104496781A (en) * | 2014-12-12 | 2015-04-08 | 上海万香日化有限公司 | Synthesis method of alkyl cyclopentene alcohol ketone |
| CN105585470A (en) * | 2014-11-07 | 2016-05-18 | 中国科学院大连化学物理研究所 | Method of preparing 2-hydroxy-3-methyl-2-cyclopentene-1-one from fructose |
| CN106366003A (en) * | 2016-08-30 | 2017-02-01 | 安徽金禾实业股份有限公司 | Method for recycling dimethylamine in MCP hydrolysis mother liquor |
| CN106431870A (en) * | 2016-09-09 | 2017-02-22 | 兰州大学 | Preparation method of 5-hydroxy-2-cyclopentenone compound |
| CN106565642A (en) * | 2016-10-31 | 2017-04-19 | 广州百花香料股份有限公司 | Synthesis method of N,N-dimethyl-5-methylfurfurylamine |
| CN110183317A (en) * | 2019-05-28 | 2019-08-30 | 南昌大学 | A kind of method that furfuryl alcohol cyclization is converted into cyclopentenone substance |
| CN110963899A (en) * | 2019-12-12 | 2020-04-07 | 山东天汉生物科技有限公司 | Optimized amination production method of methyl cyclopentenolone |
-
2020
- 2020-09-16 CN CN202010973032.5A patent/CN112142582A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58210041A (en) * | 1982-06-02 | 1983-12-07 | Sanyo Chem Ind Ltd | Production of 2-hydroxy-3-alkyl-2-cyclopenten-1-one |
| CN1100406A (en) * | 1993-06-03 | 1995-03-22 | 住友化学工业株式会社 | A process for the production of a cyclopentenol derivative |
| CN103113246A (en) * | 2012-11-11 | 2013-05-22 | 安徽金禾实业股份有限公司 | Production method of methyl cyclopentenolone via amination and step-by-step reaction |
| CN104370725A (en) * | 2014-09-27 | 2015-02-25 | 安徽金禾实业股份有限公司 | Methyl cyclopentenolone (MCP) rearrangement optimizing production method |
| CN105585470A (en) * | 2014-11-07 | 2016-05-18 | 中国科学院大连化学物理研究所 | Method of preparing 2-hydroxy-3-methyl-2-cyclopentene-1-one from fructose |
| CN104496781A (en) * | 2014-12-12 | 2015-04-08 | 上海万香日化有限公司 | Synthesis method of alkyl cyclopentene alcohol ketone |
| CN106366003A (en) * | 2016-08-30 | 2017-02-01 | 安徽金禾实业股份有限公司 | Method for recycling dimethylamine in MCP hydrolysis mother liquor |
| CN106431870A (en) * | 2016-09-09 | 2017-02-22 | 兰州大学 | Preparation method of 5-hydroxy-2-cyclopentenone compound |
| CN106565642A (en) * | 2016-10-31 | 2017-04-19 | 广州百花香料股份有限公司 | Synthesis method of N,N-dimethyl-5-methylfurfurylamine |
| CN110183317A (en) * | 2019-05-28 | 2019-08-30 | 南昌大学 | A kind of method that furfuryl alcohol cyclization is converted into cyclopentenone substance |
| CN110963899A (en) * | 2019-12-12 | 2020-04-07 | 山东天汉生物科技有限公司 | Optimized amination production method of methyl cyclopentenolone |
Non-Patent Citations (3)
| Title |
|---|
| MYONG-OCK KIM等: "On the Role of 2,3-Dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one in the Maillard Reaction", 《J. AGRIC. FOOD CHEM.》 * |
| 李云霞等: "2一羟基一3一甲基一2一环戊烯一1一酮的合成研究", 《香料香精化妆品》 * |
| 阎峰等: "香料化合物-3-甲基-2-羟基-环戊-2-烯-1-酮的合成", 《沈阳化工学院学报》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114409519A (en) * | 2021-12-16 | 2022-04-29 | 江苏宏邦化工科技有限公司 | Method for synthesizing cis-jasmone |
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