Acetal Acetal

Structural formula

• Numbering system
• Physical property data
• Toxicological data
• Ecological data
• Molecular structure data
• Computing chemical data
• More
  • Properties and Stability
  • Storage method
  • Synthesis method
  • Purpose

Numbering system

CAS number:105-57-7

MDL number:MFCD00009243

EINECS number:203-310-6

RTECS number:AB2800000

BRN number:1098310

PubChem number:24900781

Physical property data

1. Properties: Colorless and volatile liquid with aromatic odor. ^[1]

2. Melting point (℃): -100^[2]

3. Boiling point (℃): 102.7^[3]

4. Relative density (water = 1): 0.83^[4]

5. Relative vapor Density (air=1): 4.1^[5]

6. Saturated vapor pressure (kPa): 2.7 (20℃)^[6]

7. Heat of combustion (kJ/mol): -459.4^[7]

8. Critical pressure (MPa): 2.98^[8]

9. Octanol/water partition coefficient: 0.84^[9]

10. Flash point (℃): -21 (CC )^[10]

11. Ignition temperature (℃): 230^[11]

12. Explosion upper limit ( %): 10.4^[12]

13. Lower explosion limit (%): 1.6^[13]

14. Dissolution Properties: soluble in water, soluble in ethanol, ether, acetone, chloroform. ^[14]

15. Refractive index (20ºC): 1.3811

16. Ignition point (ºC): 230

17. Heat of evaporation (KJ/mol, 102.9ºC): 32.75

18. Heat of combustion (KJ/kg): 3890

19. Specific heat capacity (KJ/(kg·K), 9 ~99ºC, constant pressure): 2.18

20. Relative density (25℃, 4℃): 0.8242^41.6

21. Critical pressure (MPa) : 3.22

22. Eccentricity factor: 0.432

23. Solubility parameter (J·cm^-3)^0.5: 16.506

24. van der Waals area (cm²·mol^-1): 1.083×10¹⁰

25. van der Waals volume (cm³·mol^-1): 75.650

26. Gas phase standard heat of combustion (enthalpy )(kJ·mol^-1): -3908.3

27. The gas phase standard claims heat (enthalpy) (kJ·mol^-1): – 453.5

28. Liquid phase standard combustion heat (enthalpy) (kJ·mol^-1): -3870.49

29. Liquid phase standard claimed heat ( Enthalpy) (kJ·mol^-1): -491.4

Toxicological data

1. Skin/eye irritation: Standard Dresser test: rabbit skin contact, 500mg/24HREACTION SEVERITY, slight reaction; 2. Acute toxicity: rat oral LD50: 4600mg/kg; rat inhalation LDLo: 4000ppm/4H; Rat peritoneal cavity LD50: 900mg/kg; mouse oral LC50: 3500mg/kg; mouse peritoneal cavity LC50: 500mg/kg; rabbit oral LD50: 3545mg/kg; 3. Acetal has anesthetic properties and is harmful to the skin , eyes are slightly irritating. Inhaling high-concentration vapors can cause drowsiness.

4. Acute toxicity^[15] LD50: 4600mg/kg (rat oral); 3500mg/kg (mouse oral Oral)

5. Irritation^[16]

Rabbit transdermal: 500mg (24h), mild stimulation.

Rabbit eye: 500mg (24h), mild irritation.

Ecological data

1. Ecotoxicity^[17] LC50: 2050~9550mg/L (96h) (fish)

2. Biodegradability No data yet

3. Non-biodegradability^[18] In the air, when the concentration of hydroxyl radicals is 5.00×10⁵/cm³, the degradation half-life is 19.6h (theoretical).

Molecular structure data

1. Molar refractive index: 33.29

2. Molar volume (cm³/mol): 140.6

3. Isotonic specific volume (90.2K ): 307.5

4. Surface tension (dyne/cm): 22.8

5. Dipole moment (10^-24cm³):

6. Polarizability: 13.19

Compute chemical data

1. Reference value for hydrophobic parameter calculation (XlogP): None

2. Number of hydrogen bond donors: 0

3. Number of hydrogen bond acceptors: 2

4. Number of rotatable chemical bonds: 4

5. Number of tautomers: none

6. Topological molecule polar surface area 18.5

7. Number of heavy atoms: 8

8. Surface charge: 0

9. Complexity: 39.8

10. Number of isotope atoms: 0

11. Determine the number of atomic stereocenters: 0

12. Uncertain number of atomic stereocenters: 0

13. Determine the number of chemical bond stereocenters: 0

14. Number of uncertain chemical bond stereocenters: 0

15. Number of covalent bond units: 1

Properties and stability

1. Chemical properties: Less stable than other ethers, and has a tendency to polymerize when placed. It is stable to alkali, but can also be hydrolyzed into acetaldehyde and ethanol with weak acids at low temperatures; it reacts with hydrogen iodide gas to produce ethyl iodide and acetaldehyde; it generates acetic acid when oxidized. Stable in alkaline. In the event of a fire, use carbon dioxide, carbon tetrachloride or dry chemical fire extinguishing agents. Water is ineffective.

2. Stability^[19] Stable

3. Incompatible substances^[20] Strong oxidants, acids

4. Conditions to avoid contact ^[21] Air, light

5. Hazards of aggregation^[22] No aggregation

Storage method

Storage Precautions^[23] Stored in a cool, ventilated warehouse. Keep away from fire and heat sources. The storage temperature should not exceed 29℃. The packaging must be sealed and must not come into contact with air. They should be stored separately from oxidants and acids, and avoid mixed storage. It should not be stored in large quantities or for long periods of time. Use explosion-proof lighting and ventilation facilities. It is prohibited to use mechanical equipment and tools that are prone to sparks. The storage area should be equipped with emergency release equipment and suitable containment materials.

Synthesis method

1. The oil is obtained by the action of acetaldehyde and ethanol in the presence of anhydrous calcium chloride and a small amount of inorganic acid. It is dried with anhydrous potassium carbonate, and then fractionated to collect the 101-103.5°C fraction, which is the finished product. .

Refining method: The main impurities include ethanol, acetaldehyde, paraldehyde, peroxide, etc. During refining, it can be treated with alkaline hydrogen peroxide at 40~45℃ for 1 hour. Add sodium chloride until saturated and separate the organic layer. Dry with anhydrous potassium carbonate, filter, and add metallic sodium for distillation. Alkaline hydrogen peroxide can also be used to stir the aldehyde at 65°C to oxidize the aldehyde, then wash with water, dry with anhydrous potassium carbonate, filter, and distill with metallic sodium.

Under the condition of controlling the temperature to 8℃, slowly add the newly steamed acetaldehyde to the theoretical amount of 95% ethanol and granular anhydrous calcium chloride. Under the action of a small amount of inorganic acid, A condensation reaction occurs. After the reaction is completed, the upper layer solution is separated, washed with a small amount of water, and then dried and dehydrated by adding anhydrous potassium carbonate. Then it is distilled under normal pressure, and the 101-103.5°C fraction is collected. After that, the collected fraction is re-distilled 1 to 2 times to obtain the finished product.

Purpose

1. It can be used as a solvent, and also used in the synthesis of dyes, plastics, spices and the organic synthesis of protecting aldehyde groups. It is used as an important wine additive and can be used as a solvent. It is also used in spices, dye intermediates, resin plasticizers, sedatives, hypnotics, and solvents for Grignard reactions. Because acetal is unstable, it is generally not used as a solvent.

2. Used as a solvent, as well as in organic synthesis and the manufacture of cosmetics and perfumes. ^[24]