Method for preparing diethylaminoethanethiol

A technology of ethylaminoethanethiol and thiocyanate, which is applied in the preparation of mercaptans, organic chemistry, etc., can solve the problems that thiol is difficult to effectively condense and recover, is prone to safety accidents, and has a long reaction time, so as to avoid The risk of flushing, good product quality, and the effect of increasing the reaction temperature

Active Publication Date: 2019-01-04
保定加合精细化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

If the temperature rises rapidly, the risk of flushing is high, and it is difficult to effectively condense and recover ethylene sulfide, which is prone to safety accidents
The second step reaction is currently either adding a catalyst, or the reaction time is long, some have high cost, some have many impurities, low yield, and some are cumbersome to operate, etc.

Method used

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  • Method for preparing diethylaminoethanethiol
  • Method for preparing diethylaminoethanethiol
  • Method for preparing diethylaminoethanethiol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] Add 220 kg of ethylene carbonate (0.52 times the total amount of ethylene carbonate) in the reaction tank, heat to 55 ° C to melt, stir, add 375 kg of sodium thiocyanate, directly turn on the steam and heat up to 85 ° C, after the distillate, through The coil heat exchanger and the cyclone gas-liquid separator were used to separate and collect fractions. At the same time, the remaining 200 kg of ethylene carbonate at a temperature of 75° C. was started to be added dropwise, and the temperature was controlled at 100° C. during the dropping process. Continue to heat up to 138°C after the addition of sulfide, and stop the reaction until no distillate is evaporated. The chemical reaction and operation of this step were stable, and it took 2 hours to obtain 270.8 kg of ethylene sulfide, the gas phase detection purity was 99.6%, and the yield was 97.5%.

[0031] Transfer 270.8kg of the ethylene sulfide fraction to a 1000L autoclave, add 330kg of diethylamine, seal it and stir...

Embodiment 2

[0034] This embodiment is a small test carried out in the laboratory, the main purpose is to test the technical effect of the two-step feeding.

[0035]Add 200g of ethylene carbonate (0.49 times the total amount of ethylene carbonate) into the four-neck bottle, heat to 50°C to melt, stir, add 375g of sodium thiocyanate, heat the oil bath to 95°C, start to drop after the distillate The remaining temperature is 208g of ethylene carbonate at 65°C, and the dropwise addition process controls the temperature at 110°C. Continue to heat up to 136°C after the addition of sulfide, and stop the reaction until no distillate is evaporated. The reaction lasted for 1 hour, and 270.1 g of ethylene sulfide was obtained, the gas phase detection purity was 99.3%, and the yield was 97.2%.

[0036] Transfer 270 g of the ethylene sulfide fraction to a 1-liter autoclave, add 329 g of diethylamine, and stir in an airtight manner, heat up to 128° C., and keep the pressure at 0.4 MPa for 1 hour to com...

Embodiment 3

[0038] This embodiment is a small test carried out in the laboratory, the main purpose is to verify the reliability of the technical effect of the two-step feeding.

[0039] Add 260g of ethylene carbonate to the four-necked bottle, heat to 55°C to melt, stir, add 443g of potassium thiocyanate, heat up the oil bath to 100°C, and start to drop the remaining 160g of ethylene carbonate at 75°C after the distillate , The dropping process controlled the temperature at 105°C. Continue to heat up to 129°C after the addition of sulfide, and stop the reaction until no fraction can be evaporated. The reaction took 1.2 hours to obtain 267.2 g of sulfide, the gas phase detection purity was 99.2%, and the yield was 97.5%.

[0040] Transfer 267.1 g of the ethylene sulfide fraction to a 1-liter autoclave, add 325 g of diethylamine, and stir in an airtight manner, raise the temperature to 120° C., and keep the pressure at 0.5 MPa for 1 hour to complete the reaction to obtain diethylaminoethan...

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Abstract

The invention provides a method for preparing diethylaminoethanethiol. The method comprises the steps that 1, a part of pre-heated and liquefied ethylene carbonate with the amount being 0.2-0.7 time of the total feeding amount of ethylene carbonate is added and stirred, the temperature is controlled to be 40-70 DEG C, then thiocyanate is added, the temperature is quickly increased to 75-105 DEG C,thiirane generated by reactioni s collected through a condensation system and a gas-liquid separator, meanwhile, remaining ethylene carbonate with the temperature of 45-85 DEG C starts to be added dropwise, the temperature is controlled to be 80-110 DEG C in the dropwise adding process, the temperature continues to be increased to 130-140 DEG C after dropwise addition, and the reaction is finished until fractions cannot be evaporated; 2, thiirane and diethylamine are subjected to closed reaction and are gradually heated to 110-130 DEG C, the pressure of 0.3-0.7 MPa is kept for 0.5-1.5 h, andthe reaction is finished. The method avoids the outrush risk is avoided, the reaction time is short, the quantity of generated impurities is small, the yield of the obtained product, namely diethylaminoethanethiol, reaches 98% or above, and the gas-phase detection purity of the product is 99% or above.

Description

technical field [0001] The invention relates to the technical field of production of pharmaceutical intermediates, in particular to a preparation method of diethylaminoethanethiol, an intermediate of veterinary drug tiamulin. Background technique [0002] Diethylaminoethanethiol is an important intermediate for the synthesis of veterinary drug tiamulin. There are many synthetic methods of diethylaminoethanethiol reported in the literature, but there are two main industrial production processes at present: the first is diethylaminoethanethiol After chlorination, ethanol reacts with thiourea to generate S-substituted isothiourea salt, which is hydrolyzed with a strong base to obtain diethylaminoethanethiol; the second is first formed by the reaction of ethylene carbonate and thiocyanate Sulfur, and then diethylamine and sulphide react to generate diethylaminoethanethiol. The first process has high costs, long routes, heavy pollution, and poor operating conditions, and has bee...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C319/06C07C323/25
CPCC07C319/06C07D331/02C07C323/25
Inventor 余伟刘美龙张颖丽
Owner 保定加合精细化工有限公司
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