Complete method for preparing diethylaminoethanethiol

Abstract

A complete method for preparing diethylaminoethanethiol comprises the following steps: heating and drying thiocyanate by using a double-cone vacuum dryer, and cooling for later use after drying; carrying out cyclization reaction on ethylene carbonate and dried and heat-insulated sodium thiocyanate in a cyclization kettle to generate ethylene sulfide; and carrying out an addition reaction on the generated ethylene sulfide and excessive diethylamine in the addition kettle, putting the obtained reaction product into a distillation kettle, carrying out atmospheric distillation to collect unreacted diethylamine for direct recycling, carrying out reduced pressure distillation on the reaction product, and removing impurities to obtain the diethylaminoethanethiol. The preparation method of diethylaminoethanethiol is reasonable in process, green and environment-friendly, and high in product purity.

Description

technical field

[0001] The invention relates to the technical field of pharmaceutical intermediate manufacture, in particular to a complete method for preparing diethylaminoethanethiol. Background technique

[0002] The chemical name of 2-Diethylaminoethanethiol (2-Diethylaminoethanethiol) is 2-Diethylaminoethanethiol, and its molecular formula is C 6 h 15 NS, it is an important raw material for the preparation of veterinary antibiotic Tiamulin fumarate. In recent years, due to the rapid development of the centralized breeding industry, the demand for tiamulin fumarate has been rising steadily, so the demand for diethylaminoethanethiol, the key raw material of tiamulin fumarate, has also increased in pharmaceutical companies. increase.

[0003] According to references at home and abroad, in the prior art, there are several methods for preparing diethylaminoethanethiol, for example, diethylaminochloroethane and sodium hydrosulfide method, thioether method, etc. At present...

Examples

Embodiment 1

[0035] Use a double-cone vacuum dryer to dry sodium thiocyanate, vacuumize under negative pressure, and under the condition of vacuum degree -0.07 MPa, heat and dry sodium thiocyanate, heat up to 120°C, dry for 1.5 hours, and rotate at a speed of 3-4 r / min, water-cooled to 50°C, slowly fill the system with nitrogen to normal pressure during cooling, and seal it to achieve air isolation and heat preservation.

[0036] For the cyclization reaction of sodium thiocyanate and ethylene carbonate, add 500 kg ethylene carbonate into the cyclization kettle, start stirring at a stirring speed of 60-70 r / min, then add dry sodium thiocyanate, ethylene carbonate and sulfur The molar ratio of sodium cyanate reaction is 1:1.03, continue to fill nitrogen to the micro pressure level of 0-0.3 kpa, slowly raise the temperature to 80°C to start the reaction, stop nitrogen filling, continue to heat up, maintain 105°C, until no liquid flows out of the sight glass At the end of the distillation, the...

Embodiment 2

[0040] Use a double-cone vacuum dryer to dry sodium thiocyanate, negative pressure vacuum, vacuum degree -0.08 MPa, heat and dry sodium thiocyanate, heat up to 130 ° C, drying time 1.5 hours, speed 3-4 r / min, cool down to 48°C, slowly fill the system with nitrogen to normal pressure during cooling, and seal it to achieve air isolation and heat preservation.

[0041] For the cyclization reaction of sodium thiocyanate and ethylene carbonate, add 500 kg ethylene carbonate into the cyclization kettle, start stirring at a stirring speed of 60-70 r / min, then add dry sodium thiocyanate, ethylene carbonate and sulfur The molar ratio of sodium cyanate reaction is 1:1.1, continue to fill nitrogen to the micro pressure level of 0-0.3 kpa, slowly raise the temperature to 80°C to start the reaction, stop nitrogen filling, continue to heat up, maintain 110°C, until no liquid flows out of the sight glass At the end of the distillation, the gas phase generated by the addition reaction is cond...

technical field

[0001] The invention relates to the technical field of pharmaceutical intermediate manufacture, in particular to a complete method for preparing diethylaminoethanethiol. Background technique

[0002] The chemical name of 2-Diethylaminoethanethiol (2-Diethylaminoethanethiol) is 2-Diethylaminoethanethiol, and its molecular formula is C 6 h 15 NS, it is an important raw material for the preparation of veterinary antibiotic Tiamulin fumarate. In recent years, due to the rapid development of the centralized breeding industry, the demand for tiamulin fumarate has been rising steadily, so the demand for diethylaminoethanethiol, the key raw material of tiamulin fumarate, has also increased in pharmaceutical companies. increase.

[0003] According to references at home and abroad, in the prior art, there are several methods for preparing diethylaminoethanethiol, for example, diethylaminochloroethane and sodium hydrosulfide method, thioether method, etc. At present...

Examples

Embodiment 1

[0035] Use a double-cone vacuum dryer to dry sodium thiocyanate, vacuumize under negative pressure, and under the condition of vacuum degree -0.07 MPa, heat and dry sodium thiocyanate, heat up to 120°C, dry for 1.5 hours, and rotate at a speed of 3-4 r / min, water-cooled to 50°C, slowly fill the system with nitrogen to normal pressure during cooling, and seal it to achieve air isolation and heat preservation.

[0036] For the cyclization reaction of sodium thiocyanate and ethylene carbonate, add 500 kg ethylene carbonate into the cyclization kettle, start stirring at a stirring speed of 60-70 r / min, then add dry sodium thiocyanate, ethylene carbonate and sulfur The molar ratio of sodium cyanate reaction is 1:1.03, continue to fill nitrogen to the micro pressure level of 0-0.3 kpa, slowly raise the temperature to 80°C to start the reaction, stop nitrogen filling, continue to heat up, maintain 105°C, until no liquid flows out of the sight glass At the end of the distillation, the...

Embodiment 2

[0040] Use a double-cone vacuum dryer to dry sodium thiocyanate, negative pressure vacuum, vacuum degree -0.08 MPa, heat and dry sodium thiocyanate, heat up to 130 ° C, drying time 1.5 hours, speed 3-4 r / min, cool down to 48°C, slowly fill the system with nitrogen to normal pressure during cooling, and seal it to achieve air isolation and heat preservation.

[0041] For the cyclization reaction of sodium thiocyanate and ethylene carbonate, add 500 kg ethylene carbonate into the cyclization kettle, start stirring at a stirring speed of 60-70 r / min, then add dry sodium thiocyanate, ethylene carbonate and sulfur The molar ratio of sodium cyanate reaction is 1:1.1, continue to fill nitrogen to the micro pressure level of 0-0.3 kpa, slowly raise the temperature to 80°C to start the reaction, stop nitrogen filling, continue to heat up, maintain 110°C, until no liquid flows out of the sight glass At the end of the distillation, the gas phase generated by the addition reaction is cond...