Preparation method of dicyandiamide

A technology of dicyandiamide and triethylamine, which is applied in the field of preparation of dicyandiamide, can solve the problems of serious environmental pollution and high energy consumption in the production of lime nitrogen raw materials, achieve high yield, overcome high energy consumption and simple process. Effect

Inactive Publication Date: 2018-03-27
SHANDONG EFIRM BIOCHEMISTRY & ENVIRONMENTAL PROTECTION CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The above-mentioned lime nitrogen hydrolysis to prepare cyanamide produces a large amount of waste residue, and the production of lime nitrogen raw material pollutes the environment very seriously and consumes a lot of energy

Method used

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  • Preparation method of dicyandiamide
  • Preparation method of dicyandiamide
  • Preparation method of dicyandiamide

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Add 0.05mol urea, 30mL tetrahydrofuran, and 0.045mol triethylamine into the four-necked flask, and then add 0.015mol phosphorus oxychloride in batches at intervals of 20 minutes, and add 0.015mol phosphorus oxychloride in batches at 45°C for 5 hours. Yellow transparent liquid. After the reaction was over, the solvent was distilled off under reduced pressure, and the solvent was distilled off with saturated NaCO 3 Wash the distillation product, add ethanol to remove the salt in the system, and filter. The product was extracted with ethyl acetate, and the conversion rate of urea was 100% and the yield was 92.9% through liquid-mass analysis and liquid phase quantitative analysis.

Embodiment 2

[0027] Add 0.5mol urea, 150mL tetrahydrofuran, and 0.45mol triethylamine into the four-neck flask, and then add 0.15mol phosphorus oxychloride in batches at intervals of 20 minutes, and add 0.15mol phosphorus oxychloride in batches at 55°C for 6 hours. Yellow transparent liquid. After the reaction was over, the solvent was distilled off under reduced pressure, and the solvent was distilled off with saturated NaHCO 3 Wash the distillation product, add ethanol to remove the salt in the system, and filter. The product was extracted with ethyl acetate, and the conversion rate of urea was 100% and the yield was 87.3% through liquid-mass analysis and liquid phase quantitative analysis.

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Abstract

The invention belongs to the field of chemical synthesis, and concretely provides a preparation method of dicyandiamide. The method comprises the following steps: a dehydration and polymerization reaction is carried out under existence of an acid binding agent triethylamine for urea and phosphorous oxychloride in order to obtain dicyandiamide; the reaction is carried out at 50 DEG C and at a normal pressure, and after the reaction ends, alkali washing, filtering, extraction and condensation are carried out in order to obtain dicyandiamide. Dehydration of urea is carried out in order to preparedicyandiamide, the waste residue problem generated in the traditional process can be effectively solved, and the method has the advantages of energy saving, green and environmental protection, high yield, simple process, and the like.

Description

technical field [0001] The invention belongs to the field of chemical synthesis, in particular to a preparation method of dicyandiamide. Background technique [0002] The chemical formula of dicyandiamide (dicyandiamide) is as follows: [0003] [0004] It is a dimer of cyanamide and a cyano derivative of guanidine, white crystalline powder, soluble in water, alcohol, DMF, etc., almost insoluble in ether and benzene, non-flammable, and stable when dry. Dicyandiamide is an important raw material for fine chemical intermediates, widely used in medicine, dyes, pesticides, electronics, lubricants, etc. For example: in the synthesis of medicine, it is used to prepare sulfa drugs and guanidine nitrate. [0005] The traditional production process of dicyandiamide is to hydrolyze lime nitrogen, and at the same time, carbon dioxide is introduced into the reaction system to precipitate the calcium in the system in the form of calcium carbonate, and the cyanamide solution is obtai...

Claims

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Application Information

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IPC IPC(8): C07C279/28C07C277/08
CPCC07C277/08C07C279/28
Inventor 丁宗旺马韵升陈梅梅邢莹莹常忠臣张建林高德振张金国易先君郭龙龙
Owner SHANDONG EFIRM BIOCHEMISTRY & ENVIRONMENTAL PROTECTION CO LTD
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