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 saturated carbon ring-containing compounds, is an important chemical intermediate. For example, 3-cyclohexylpropionic acid (commonly known as pineapple vinegar) is the synthesis of allyl cyclohexylpropionate (commonly known as pineapple ester or pineapple vinegar). Flavor), and pineapple ester is an important food additive, widely used in food, cosmetics, tobacco, light industry and other fields. Pineapple esters are obtained by the esterification reaction of 3-cyclohexylpropionic acid and allyl alcohol, and the synthesis of 3-cyclohexylpropionic acid is the key raw material for producing pineapple esters. 3-Cyclohexylpropionic acid is not only used for the synthesis of pineapple ester, but also can be used to prepare insect attractant components (such as mixed wi...

Examples

Embodiment 1

[0035] Embodiment 1: the preparation of cyclohexyl propionic acid

[0036] method one

[0037] The first step: the preparation of cyclohexenamine

[0038] Get 15 grams of cyclohexanone and the macroporous strong acid resin of 5% of the total material mass into a four-necked flask, heat in an oil bath and stir for 20 minutes, add 100 milliliters of cyclohexane, continue to heat to 60 ° C and stir, Vacuumize and decompress 0.065MPa. When the solvent in the water separator becomes turbid and the spherical condenser has reflux, add 13.3 grams of morpholine dropwise. Raise the temperature to 80°C. When no water comes out, continue After half an hour of reflux, the reaction was terminated. The entire reaction process lasted for 3 hours. Post-treatment: filter the product liquid, dry it with an appropriate amount of anhydrous magnesium sulfate, filter it, remove the solvent by rotary evaporation to obtain 28.2 grams of crude product, and distill it under reduced pressure to obtain ...

Embodiment 2

[0073] Embodiment 2: the preparation of cyclopentylpropionic acid

[0074] The first step: the preparation of cyclopentenylamine

[0075] Get 15 grams of cyclopentanone and the macroporous strong acid resin of 5% of the total material and put it into a four-neck flask, heat and stir in an oil bath for 20 minutes, add 100 milliliters of cyclohexane, continue to heat to 60 degrees and stir, vacuumize and 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, and continue to reflux for half an hour when there is no water coming out After finishing the reaction, the whole reaction process went through 3 hours. Aftertreatment: filter the product liquid, dry it with an appropriate amount of anhydrous magnesium sulfate, then filter, suspend to remove the solvent and distill under reduced pressure to obtain 28.2 grams of crude product. Pure pro...

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 saturated carbon ring-containing compounds, is an important chemical intermediate. For example, 3-cyclohexylpropionic acid (commonly known as pineapple vinegar) is the synthesis of allyl cyclohexylpropionate (commonly known as pineapple ester or pineapple vinegar). Flavor), and pineapple ester is an important food additive, widely used in food, cosmetics, tobacco, light industry and other fields. Pineapple esters are obtained by the esterification reaction of 3-cyclohexylpropionic acid and allyl alcohol, and the synthesis of 3-cyclohexylpropionic acid is the key raw material for producing pineapple esters. 3-Cyclohexylpropionic acid is not only used for the synthesis of pineapple ester, but also can be used to prepare insect attractant components (such as mixed wi...

Examples

Embodiment 1

[0035] Embodiment 1: the preparation of cyclohexyl propionic acid

[0036] method one

[0037] The first step: the preparation of cyclohexenamine

[0038] Get 15 grams of cyclohexanone and the macroporous strong acid resin of 5% of the total material mass into a four-necked flask, heat in an oil bath and stir for 20 minutes, add 100 milliliters of cyclohexane, continue to heat to 60 ° C and stir, Vacuumize and decompress 0.065MPa. When the solvent in the water separator becomes turbid and the spherical condenser has reflux, add 13.3 grams of morpholine dropwise. Raise the temperature to 80°C. When no water comes out, continue After half an hour of reflux, the reaction was terminated. The entire reaction process lasted for 3 hours. Post-treatment: filter the product liquid, dry it with an appropriate amount of anhydrous magnesium sulfate, filter it, remove the solvent by rotary evaporation to obtain 28.2 grams of crude product, and distill it under reduced pressure to obtain ...

Embodiment 2

[0073] Embodiment 2: the preparation of cyclopentylpropionic acid

[0074] The first step: the preparation of cyclopentenylamine

[0075] Get 15 grams of cyclopentanone and the macroporous strong acid resin of 5% of the total material and put it into a four-neck flask, heat and stir in an oil bath for 20 minutes, add 100 milliliters of cyclohexane, continue to heat to 60 degrees and stir, vacuumize and 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, and continue to reflux for half an hour when there is no water coming out After finishing the reaction, the whole reaction process went through 3 hours. Aftertreatment: filter the product liquid, dry it with an appropriate amount of anhydrous magnesium sulfate, then filter, suspend to remove the solvent and distill under reduced pressure to obtain 28.2 grams of crude product. Pure pro...

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