New synthetic method of guaiacol glycerin ether

Abstract

The invention discloses a new synthetic method of guaiacol glycerin ether with a structure as shown in a formula (IV), isopropylidene glycerol-4-methanol with a structure as shown in formula (I) and guaiacol with a structure as shown in a formula (II) are taken as raw materials, Mitsunobu reaction occurs in organic solvent under the effect of triphenylphosphine and diisopropyl azodicarboxylate to generate intermediate product guaiacol isopropylidene glycerol ether with the structure as shown in formual (III); after full reaction, the obtained intermediate product crude product from separation witnesses hydrolysis reaction directly under acid conditions without purification; after separation and purification of the reaction liquid, the target product guaiacol glycerin with the structure as shown in (IV) ether is obtained. The synthetic method of the invention features application of clean raw material with low cost and easy availability, moderate reaction conditions, simple post treatment processes and adaptability to industrialized production.

Description

(1) Technical field

[0001] The invention relates to a new method for synthesizing guaiacol glyceryl ether, which belongs to the technical field of medicine and chemical industry. (2) Background technology

[0002] Guaifenesin (chemical name: 3-o-methoxyphenoxy-1,2-propanediol), an expectorant, has antitussive and antispasmodic effects. Because the drug has the advantages of accurate dosage, convenience, and rapid drug effect, it is widely used as an over-the-counter drug in daily life. At the same time, it is also a biologically active pharmaceutical intermediate used in the synthesis of β-receptor blockers. In recent years, studies have found that the drug can also be used to reduce the viscosity of platelets, relax muscles, and veterinary anesthetics, etc., greatly deepening the application prospects of the drug.

[0003] There are four reported methods for the synthesis of guaiacol.

[0004] Method one is to condense epichlorohydrin and guaiacol (o-methoxyphenol) under...

Examples

Embodiment 1

[0031] Add 1.32g (0.010mol) isopropylidene glycerol, 1.24g (0.010mol) guaiacol, 2.62g (0.010mol) triphenylphosphine, 10mL tetrahydrofuran into a 50mL three-necked flask, slowly add 2.0 mL (0.010mol) of diisopropyl azodicarboxylate, after the dropwise addition, the temperature was raised to 60°C. After reacting for 12 hours, it was washed with 80 mL of 5% sodium hydroxide solution for 4 times, and with 60 mL of saturated saline for 3 times. , 40 mL of clear water and washed twice, then dried and concentrated to obtain the crude intermediate product. Add 20 mL of 10% hydrochloric acid to the above crude product, and heat to 80° C. for 4 h. After cooling, add 25 mL of 10% sodium hydroxide solution to neutralize. Acetone was distilled off. Cool, filter, and extract the filtrate with dichloromethane. The extract was dried, concentrated, and recrystallized from toluene to obtain 0.75 g of guaiacol glycerol, with a yield of 38%, and a melting point of 78-79°C.

Embodiment 2

[0033] Add 1.32g (0.010mol) isopropylidene glycerol, 3.72g (0.030mol) guaiacol, 7.86g (0.030mol) triphenylphosphine, 30mL tetrahydrofuran into a 50mL three-necked flask, slowly add 6.0 mL (0.030mol) of diisopropyl azodicarboxylate, after the dropwise addition, the temperature was raised to 60°C. After reacting for 12 hours, it was washed with 80 mL of 20% sodium hydroxide solution for 4 times, and with 60 mL of saturated saline for 3 times. , 40 mL of clear water and washed twice, then dried and concentrated to obtain the crude intermediate product. Add 20 mL of 10% hydrochloric acid to the above crude product, and heat to 80° C. for 4 h. After cooling, add 25 mL of 10% sodium hydroxide solution to neutralize. Acetone was distilled off. Cool, filter, and extract the filtrate with dichloromethane. The extract was dried, concentrated, and recrystallized from toluene to obtain 1.58 g of guaiacol glyceryl ether, with a yield of 80%.

Embodiment 3

[0035] Add 1.32g (0.010mol) isopropylidene glycerol, 1.36g (0.011mol) guaiacol, 2.88g (0.011mol) triphenylphosphine, 20mL tetrahydrofuran into a 50mL three-necked flask, slowly add 2.2 mL (0.011mol) of diisopropyl azodicarboxylate, after the dropwise addition, the temperature was raised to 60°C, and after 12 hours of reaction, it was washed with 80 mL of 20% sodium hydroxide solution for 4 times, and 60 mL of saturated saline for 3 times. , 40 mL of clear water and washed twice, then dried and concentrated to obtain the crude intermediate product. Add 20 mL of 10% hydrochloric acid to the above crude product, and heat to 80° C. for 4 h. After cooling, add 25 mL of 10% sodium hydroxide solution to neutralize. Acetone was distilled off. Cool, filter, and extract the filtrate with dichloromethane. The extract was dried, concentrated, and recrystallized from toluene to obtain 1.54 g of guaiacol glyceryl ether, with a yield of 78%.

(1) Technical field

[0001] The invention relates to a new method for synthesizing guaiacol glyceryl ether, which belongs to the technical field of medicine and chemical industry. (2) Background technology

[0002] Guaifenesin (chemical name: 3-o-methoxyphenoxy-1,2-propanediol), an expectorant, has antitussive and antispasmodic effects. Because the drug has the advantages of accurate dosage, convenience, and rapid drug effect, it is widely used as an over-the-counter drug in daily life. At the same time, it is also a biologically active pharmaceutical intermediate used in the synthesis of β-receptor blockers. In recent years, studies have found that the drug can also be used to reduce the viscosity of platelets, relax muscles, and veterinary anesthetics, etc., greatly deepening the application prospects of the drug.

[0003] There are four reported methods for the synthesis of guaiacol.

[0004] Method one is to condense epichlorohydrin and guaiacol (o-methoxyphenol) under...

Examples

Embodiment 1

[0031] Add 1.32g (0.010mol) isopropylidene glycerol, 1.24g (0.010mol) guaiacol, 2.62g (0.010mol) triphenylphosphine, 10mL tetrahydrofuran into a 50mL three-necked flask, slowly add 2.0 mL (0.010mol) of diisopropyl azodicarboxylate, after the dropwise addition, the temperature was raised to 60°C. After reacting for 12 hours, it was washed with 80 mL of 5% sodium hydroxide solution for 4 times, and with 60 mL of saturated saline for 3 times. , 40 mL of clear water and washed twice, then dried and concentrated to obtain the crude intermediate product. Add 20 mL of 10% hydrochloric acid to the above crude product, and heat to 80° C. for 4 h. After cooling, add 25 mL of 10% sodium hydroxide solution to neutralize. Acetone was distilled off. Cool, filter, and extract the filtrate with dichloromethane. The extract was dried, concentrated, and recrystallized from toluene to obtain 0.75 g of guaiacol glycerol, with a yield of 38%, and a melting point of 78-79°C.

Embodiment 2

[0033] Add 1.32g (0.010mol) isopropylidene glycerol, 3.72g (0.030mol) guaiacol, 7.86g (0.030mol) triphenylphosphine, 30mL tetrahydrofuran into a 50mL three-necked flask, slowly add 6.0 mL (0.030mol) of diisopropyl azodicarboxylate, after the dropwise addition, the temperature was raised to 60°C. After reacting for 12 hours, it was washed with 80 mL of 20% sodium hydroxide solution for 4 times, and with 60 mL of saturated saline for 3 times. , 40 mL of clear water and washed twice, then dried and concentrated to obtain the crude intermediate product. Add 20 mL of 10% hydrochloric acid to the above crude product, and heat to 80° C. for 4 h. After cooling, add 25 mL of 10% sodium hydroxide solution to neutralize. Acetone was distilled off. Cool, filter, and extract the filtrate with dichloromethane. The extract was dried, concentrated, and recrystallized from toluene to obtain 1.58 g of guaiacol glyceryl ether, with a yield of 80%.

Embodiment 3

[0035] Add 1.32g (0.010mol) isopropylidene glycerol, 1.36g (0.011mol) guaiacol, 2.88g (0.011mol) triphenylphosphine, 20mL tetrahydrofuran into a 50mL three-necked flask, slowly add 2.2 mL (0.011mol) of diisopropyl azodicarboxylate, after the dropwise addition, the temperature was raised to 60°C, and after 12 hours of reaction, it was washed with 80 mL of 20% sodium hydroxide solution for 4 times, and 60 mL of saturated saline for 3 times. , 40 mL of clear water and washed twice, then dried and concentrated to obtain the crude intermediate product. Add 20 mL of 10% hydrochloric acid to the above crude product, and heat to 80° C. for 4 h. After cooling, add 25 mL of 10% sodium hydroxide solution to neutralize. Acetone was distilled off. Cool, filter, and extract the filtrate with dichloromethane. The extract was dried, concentrated, and recrystallized from toluene to obtain 1.54 g of guaiacol glyceryl ether, with a yield of 78%.

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