Acetamide;Ethanamide

Acetamide is an amide derived from acetic acid with the molecular formula CH3CONH2. The pure product is a white crystalline solid at room temperature and can be obtained from ammonium acetate dehydration. It is used as a plasticizer and an important raw material for organic synthesis.
Chinese name: Acetamide
English name: Acetamide
Chinese alias: Acetamide; Jiefluolin; Acetamide
English alias: Acetic acid amide; Acetimidic Acid; Ethanamide; Methanecarboxamide;
CAS Number: 60-35-5
Molecular formula: C2H5NO
Molecular mass: 59.0672
Content: 98%
Physical data
1. Properties: colorless hexagonal crystals. The pure product is odorless, but usually has a rat smell.
2. Boiling point (ºC, 101.3kPa): 221.15
3. Melting point (ºC): 81
4. Relative density (g/mL, 91.1/4ºC): 0.9892
5. Relative density (g/mL, 111.8/4ºC): 0.9711
6. Relative density (d204): 1.159
7. Refractive index (80ºC): 1.4270
8. Refractive index (110ºC): 1.4158
9. Refractive index (130ºC): 1.4079
10. Viscosity (mPa·s, 91.1ºC): 2.182
11. Viscosity (mPa·s, 111.8ºC): 1.46
12. Viscosity (mPa·s, 131.7ºC): 1.056
13. Flash point (ºC, closed): >104
14. Ignition point (ºC): 445
15. Heat of evaporation (KJ/mol, b.p.): 56.1
16. Heat of fusion (KJ/mol, 80ºC): 15.717
17. Heat of formation (KJ/mol): -320.7
18. Heat of combustion (KJ/mol, 25ºC, liquid): 1199.5
19. Specific heat capacity (KJ/(kg·K), 80~150ºC, constant pressure): 2.81
20. Conductivity (S/m, 83.2ºC): 8.8×10-7
21. Conductivity (S/m, 100ºC): 4.3×10-7
22. Freezing point (ºC): 80
23. Solubility: soluble in liquid ammonia, aliphatic amines, water, alcohol, pyridine, chloroform, glycerin, hot benzene, butanone, butanol, benzyl alcohol, cyclohexanone, isoamyl alcohol, etc., slightly soluble in benzene, Insoluble in ether. It can dissolve most inorganic salts well.
resolve resolution
1. Glacial acetic acid is passed through ammonia to generate ammonium acetate, which is then dehydrated by pyrolysis to obtain acetamide, which is crystallized and separated to obtain finished products. Raw material consumption quota: acetic acid (99%) 1700kg/t, liquid ammonia (99%) 750kg/t. Laboratory synthesis can follow the steps below. Put 3kg of glacial acetic acid in a 5L flask and add ammonium carbonate equivalent to 400g of ammonia. The flask is equipped with a high-efficiency fractionating column, condenser and receiver. The reaction mixture is heated to boil slowly, and the heating is adjusted so that the distillation rate does not exceed 180 mg/h, until the top temperature reaches 110°C. Get 1400-1500ml water and acetic acid mixture. Change the receiver, slowly increase the heating, continue distillation at the same speed, until the top temperature rises to 140 ℃. Get 500-700ml of distillate, mainly acetic acid, which is reserved for next feeding. Transfer the remainder into a flask with a fractionating column and an air condenser, and distill under normal pressure to collect the fractions before 210°C and 210-216°C respectively. The latter is acetamide, weighing 1150-1200g, the former can also be distilled to recover part of the product, the total weight of the two is 1200-1250g, and the yield is 87%-90%. Acetamide is often refined by distillation and solvent recrystallization. Commonly used solvents are acetone, benzene, ethyl acetate, methyl acetate, chloroform, dioxane or a mixture of benzene and ethyl acetate. For example, if 1 kg of acetamide prepared by the above method is recrystallized with a mixed solvent of 1 L of benzene and 300 ml of ethyl acetate, pure colorless needles can be obtained. The product obtained from industrial production has a purity of not less than 98% and a freezing point of not less than 76°C.
Refining method: Acetamide is usually refined by distillation and solvent recrystallization. Commonly used solvents are acetone, benzene, ethyl acetate, methyl acetate, chloroform, dioxane or a mixture of benzene and ethyl acetate (3:1 and 1:1) and so on. In addition, it can also be refined by decompression sublimation.
The main purpose
1. Molten acetamide is an excellent solvent for a variety of organic and inorganic substances. It can be used as a solubilizer when some substances with low water solubility are dissolved in water, such as a solvent and solubilizer for dyes in the fiber industry. It is also widely used as a stabilizer for plasticizers, an antacid in the cosmetics industry, a wetting agent in the paper industry, and as a solvent in the synthesis of chloramphenicol and other antibiotics. 2. Used as analytical reagent, solvent, stabilizer and plasticizer. It can also be used in organic synthesis, pharmaceutical industry, and dye preparation. 3. It is also used to make hygroscopic agents and lubricants.