Preparation method of naphthenic propionic acid

Abstract

The invention relates to a preparation method of a naphthenic propionic acid, relating to the field of organic synthesis, The preparation method of the naphthenic propionic acid comprises the following steps of: synthesizing an enamine midbody by using naphthenone as an initial raw material with organic amines (tetrahydropyrrole, morpholine, piperidine, and the like); then carrying out Michael addition reaction with methyl acrylate; then reducing the carbonyl of cyclic ketone by adopting palladium-carbon hydrogenation reduction reaction; and also hydrolyzing to obtain the naphthenic propionicacid. The preparation method of the naphthenic propionic acid has the advantages of extensive raw material source, moderate preparation condition, high yield and capability of realizing solvent recycling, the prevention of use of a reagent and the solvent which can cause environmental pollution in heavy metal catalysis and industrialized production, and high economic benefits.

Description

technical field

[0001] The invention relates to the field of organic synthesis, in particular to a preparation method of cycloalkylpropionic acid. Background technique

[0002] Cycloalkylpropionic acid, a class of compounds containing saturated carbocyclic rings, is an important chemical intermediate. Flavor), and pineapple ester is an important food additive, which is widely used in food, cosmetics, tobacco, light industry and other fields. Pineapple ester is obtained by esterification of 3-cyclohexylpropionic acid and allyl alcohol, and the synthesis of 3-cyclohexylpropionic acid is the key raw material for producing pineapple ester. In addition to synthesizing pineapple ester, 3-cyclohexylpropionic acid can also be used to formulate insect traps (such as mixing with eugenol), etc. As an important fine chemical product, pineapple vinegar, its traditional production method According to the US patent US2850519, 2-(-β) nitrile ethyl cyclohexanone is obtained by using cycloh...

Examples

Embodiment 1

[0035] Example 1: Preparation of cyclohexylpropionic acid

[0036] method one

[0037] The first step: the preparation of cyclohexenamine

[0038] Take 15 grams of cyclohexanone and macroporous strong acid resin calculated as 5% of the total material mass into a four-necked flask, heat in an oil bath and stir for 20 minutes, add 100 ml of cyclohexane, continue to heat to 60 ° C and stir, Vacuum and reduce the pressure by 0.065MPa. When the solvent in the water separator is turbid and there is reflux at the spherical condenser, add 13.3 grams of morpholine dropwise, raise the temperature to 80 °C until no water comes out, continue The reaction was terminated after refluxing for half an hour, and the whole reaction process took 3 hours. After-treatment: the product liquid was filtered, dried with an appropriate amount of anhydrous magnesium sulfate, filtered, and the solvent was removed by rotary evaporation to obtain 28.2 g of a crude product, which was distilled under reduced...

Embodiment 2

[0072] Example 2: Preparation of cyclopentylpropionic acid

[0073] The first step: the preparation of cyclopentenamine

[0074] Take 15 grams of cyclopentanone and 5% of the total material macroporous strong acid resin into a four-necked flask, heat in an oil bath and stir for 20 minutes, add 100 ml of cyclohexane, continue to heat to 60 degrees and stir, vacuum to reduce Pressure 0.065MP, when the solvent in the water separator is turbid and there is reflux at the spherical condenser, add 17 grams of morpholine dropwise, raise the temperature to 80 degrees until no water comes out, continue to reflux for half an hour After finishing the reaction, the whole reaction process went through 3 hours, post-processing: the product liquid was filtered, dried with an appropriate amount of anhydrous magnesium sulfate, filtered again, the solvent was suspended and evaporated under reduced pressure to obtain 28.2 grams of crude product, which was obtained by under reduced pressure distil...

technical field

[0001] The invention relates to the field of organic synthesis, in particular to a preparation method of cycloalkylpropionic acid. Background technique

[0002] Cycloalkylpropionic acid, a class of compounds containing saturated carbocyclic rings, is an important chemical intermediate. Flavor), and pineapple ester is an important food additive, which is widely used in food, cosmetics, tobacco, light industry and other fields. Pineapple ester is obtained by esterification of 3-cyclohexylpropionic acid and allyl alcohol, and the synthesis of 3-cyclohexylpropionic acid is the key raw material for producing pineapple ester. In addition to synthesizing pineapple ester, 3-cyclohexylpropionic acid can also be used to formulate insect traps (such as mixing with eugenol), etc. As an important fine chemical product, pineapple vinegar, its traditional production method According to the US patent US2850519, 2-(-β) nitrile ethyl cyclohexanone is obtained by using cycloh...

Examples

Embodiment 1

[0035] Example 1: Preparation of cyclohexylpropionic acid

[0036] method one

[0037] The first step: the preparation of cyclohexenamine

[0038] Take 15 grams of cyclohexanone and macroporous strong acid resin calculated as 5% of the total material mass into a four-necked flask, heat in an oil bath and stir for 20 minutes, add 100 ml of cyclohexane, continue to heat to 60 ° C and stir, Vacuum and reduce the pressure by 0.065MPa. When the solvent in the water separator is turbid and there is reflux at the spherical condenser, add 13.3 grams of morpholine dropwise, raise the temperature to 80 °C until no water comes out, continue The reaction was terminated after refluxing for half an hour, and the whole reaction process took 3 hours. After-treatment: the product liquid was filtered, dried with an appropriate amount of anhydrous magnesium sulfate, filtered, and the solvent was removed by rotary evaporation to obtain 28.2 g of a crude product, which was distilled under reduced...

Embodiment 2

[0072] Example 2: Preparation of cyclopentylpropionic acid

[0073] The first step: the preparation of cyclopentenamine

[0074] Take 15 grams of cyclopentanone and 5% of the total material macroporous strong acid resin into a four-necked flask, heat in an oil bath and stir for 20 minutes, add 100 ml of cyclohexane, continue to heat to 60 degrees and stir, vacuum to reduce Pressure 0.065MP, when the solvent in the water separator is turbid and there is reflux at the spherical condenser, add 17 grams of morpholine dropwise, raise the temperature to 80 degrees until no water comes out, continue to reflux for half an hour After finishing the reaction, the whole reaction process went through 3 hours, post-processing: the product liquid was filtered, dried with an appropriate amount of anhydrous magnesium sulfate, filtered again, the solvent was suspended and evaporated under reduced pressure to obtain 28.2 grams of crude product, which was obtained by under reduced pressure distil...

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