(R)-acetyl carnitine hydrochloride preparation method

Abstract

The present invention relates to a method for preparing (R)-acetyl carnitine hydrochloride by adopting L-carnitine hydrochloride as a raw material. According to the present invention, the problem that the high reaction temperature and the distillation operation process make the material heating time too long so as to cause side effects and produce a large amount of the glacial acetic acid-containing waste liquid in the existing process is solved, the product quality is good, and the yield is high.

Description

(1) Technical field

[0001] The invention belongs to the field of drug synthesis (2) Technical background

[0002] Acetyl L-carnitine hydrochloride, the English name is (R)-Acetyl carnitine hydrochloride, its structural formula is:

[0003]

[0004] Acetyl-levocarnitine is an endogenous substrate for the synthesis of acetylcholine in the human brain, and has neuroprotective and mitochondrial protective effects. It can actively participate in the energy metabolism of mitochondria in cells and correct the DNA transcription of mitochondria. Acetyl-L-carnitine thus prevents the aging and degenerative processes of the nervous system. Because it can stimulate nerve cells to produce protein core cell membranes and release the nerve mediator - acetylcholine, it has the effect of promoting memory improvement and improving recognition ability. Its clinical application is mostly in the form of hydrochloride, namely: acetyl L-carnitine Tine hydrochloride.

[0005] According to rep...

Examples

Embodiment 1

[0018] Add 100 grams of levocarnitine hydrochloride (0.505mol), 51.5 grams of acetic anhydride (0.505mol, about 48ml), and 10 grams of p-toluenesulfonic acid in a three-necked flask equipped with mechanical stirring, a thermometer, and a reflux condenser, and stir Heat to 70-75°C to react for 1.5 hours, cool to 25°C, add 200 ml of diethyl ether, stir and filter, add 400 ml of isopropanol to the filtrate, stir and crystallize at room temperature for 3 hours, filter, and dry the filter cake under reduced pressure at 50°C for 5 hours to obtain Crude product 110 grams.

[0019] Mix 110 g of the crude product with 330 ml of ethanol, add 6 g of activated carbon, heat to reflux to dissolve, decolorize for 30 minutes, filter while hot, and stir the filtrate overnight at room temperature. After filtering, the filter cake was dried at 50° C. for 5 hours to obtain 85 grams of refined product with a purity of 99.3%.

Embodiment 2

[0021] Add 100 grams of levocarnitine hydrochloride (0.505mol), 53 grams of acetic anhydride (0.52mol, about 48ml), and 10 grams of p-toluenesulfonic acid in a three-necked flask equipped with mechanical stirring, a thermometer, and a reflux condenser, and stir Heat to 70-75°C to react for 1.5 hours, cool to 25°C, add 200 ml of diethyl ether, stir and filter, add 400 ml of isopropanol to the filtrate, stir and crystallize at room temperature for 3 hours, filter, and dry the filter cake under reduced pressure at 50°C for 5 hours to obtain The crude product is 108 grams.

[0022] Mix 100 g of crude product with 300 ml of ethanol, add 6 g of activated carbon, heat to reflux to dissolve, decolorize for 30 minutes, filter while hot, add 50 ml of water to the filtrate at room temperature and stir overnight. After filtering, the filter cake was dried at 50° C. for 5 hours to obtain 80 grams of refined product with a purity of 99.5%.

Embodiment 3

[0024] Add 100 grams of levocarnitine hydrochloride (0.505mol), 51.5 grams of acetic anhydride (0.52mol, about 48ml), and 8 grams of trifluoroacetic acid in a three-necked flask equipped with mechanical stirring, a thermometer, and a reflux condenser, and stir and heat React at 70-75°C for 2 hours, cool to 25°C, add 200 ml of diethyl ether, stir and filter, add 400 ml of isopropanol to the filtrate, stir and crystallize at room temperature for 3 hours, filter, and dry the filter cake under reduced pressure at 50°C for 5 hours to obtain the crude product 96 grams.

[0025] Mix 90 g of the crude product with 270 ml of ethanol, add 6 g of activated carbon, heat to reflux to dissolve, decolorize for 30 minutes, filter while hot, add 45 ml of water to the filtrate at room temperature and stir overnight. After filtering, the filter cake was dried at 50° C. for 5 hours to obtain 70 grams of refined product with a purity of 99.55%.

(1) Technical field

[0001] The invention belongs to the field of drug synthesis (2) Technical background

[0002] Acetyl L-carnitine hydrochloride, the English name is (R)-Acetyl carnitine hydrochloride, its structural formula is:

[0003]

[0004] Acetyl-levocarnitine is an endogenous substrate for the synthesis of acetylcholine in the human brain, and has neuroprotective and mitochondrial protective effects. It can actively participate in the energy metabolism of mitochondria in cells and correct the DNA transcription of mitochondria. Acetyl-L-carnitine thus prevents the aging and degenerative processes of the nervous system. Because it can stimulate nerve cells to produce protein core cell membranes and release the nerve mediator - acetylcholine, it has the effect of promoting memory improvement and improving recognition ability. Its clinical application is mostly in the form of hydrochloride, namely: acetyl L-carnitine Tine hydrochloride.

[0005] According to rep...

Examples

Embodiment 1

[0018] Add 100 grams of levocarnitine hydrochloride (0.505mol), 51.5 grams of acetic anhydride (0.505mol, about 48ml), and 10 grams of p-toluenesulfonic acid in a three-necked flask equipped with mechanical stirring, a thermometer, and a reflux condenser, and stir Heat to 70-75°C to react for 1.5 hours, cool to 25°C, add 200 ml of diethyl ether, stir and filter, add 400 ml of isopropanol to the filtrate, stir and crystallize at room temperature for 3 hours, filter, and dry the filter cake under reduced pressure at 50°C for 5 hours to obtain Crude product 110 grams.

[0019] Mix 110 g of the crude product with 330 ml of ethanol, add 6 g of activated carbon, heat to reflux to dissolve, decolorize for 30 minutes, filter while hot, and stir the filtrate overnight at room temperature. After filtering, the filter cake was dried at 50° C. for 5 hours to obtain 85 grams of refined product with a purity of 99.3%.

Embodiment 2

[0021] Add 100 grams of levocarnitine hydrochloride (0.505mol), 53 grams of acetic anhydride (0.52mol, about 48ml), and 10 grams of p-toluenesulfonic acid in a three-necked flask equipped with mechanical stirring, a thermometer, and a reflux condenser, and stir Heat to 70-75°C to react for 1.5 hours, cool to 25°C, add 200 ml of diethyl ether, stir and filter, add 400 ml of isopropanol to the filtrate, stir and crystallize at room temperature for 3 hours, filter, and dry the filter cake under reduced pressure at 50°C for 5 hours to obtain The crude product is 108 grams.

[0022] Mix 100 g of crude product with 300 ml of ethanol, add 6 g of activated carbon, heat to reflux to dissolve, decolorize for 30 minutes, filter while hot, add 50 ml of water to the filtrate at room temperature and stir overnight. After filtering, the filter cake was dried at 50° C. for 5 hours to obtain 80 grams of refined product with a purity of 99.5%.

Embodiment 3

[0024] Add 100 grams of levocarnitine hydrochloride (0.505mol), 51.5 grams of acetic anhydride (0.52mol, about 48ml), and 8 grams of trifluoroacetic acid in a three-necked flask equipped with mechanical stirring, a thermometer, and a reflux condenser, and stir and heat React at 70-75°C for 2 hours, cool to 25°C, add 200 ml of diethyl ether, stir and filter, add 400 ml of isopropanol to the filtrate, stir and crystallize at room temperature for 3 hours, filter, and dry the filter cake under reduced pressure at 50°C for 5 hours to obtain the crude product 96 grams.

[0025] Mix 90 g of the crude product with 270 ml of ethanol, add 6 g of activated carbon, heat to reflux to dissolve, decolorize for 30 minutes, filter while hot, add 45 ml of water to the filtrate at room temperature and stir overnight. After filtering, the filter cake was dried at 50° C. for 5 hours to obtain 70 grams of refined product with a purity of 99.55%.

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