3-Methylvaleric acid β-Methylvaleric acid

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:105-43-1

MDL number:MFCD00002729

EINECS number:203-297-7

RTECS number:None

BRN number:1720696

PubChem ID:None

Physical property data

1. Properties: colorless liquid, sour, herbal smell, slightly green.

2. Density (g/mL, 25℃): 0.926

3. Relative density (20℃, 4℃): 0.9262

4. Melting point (ºC): -41.6

5. Boiling point (ºC, normal pressure): 197.5~198

6. Boiling point (ºC, 0.133kpa): 63

7. Refractive index _(n²⁰_D): 1.4159

8. Flash point (ºC): 85

9. Refractive index at room temperature (n²⁰): 1.4159

10. Autoignition point or ignition temperature (ºC): Undetermined

11. Vapor pressure (mmHg, 20ºC): Undetermined

12. Saturated vapor pressure (kPa, ℃): Undetermined

13. Heat of combustion (KJ/mol) : Undetermined

14. Critical temperature (ºC): Undetermined

15. Critical pressure (KPa): Undetermined

16. Oil and water (octanol /water) logarithmic value of the distribution coefficient: Undetermined

17. Explosion upper limit (%, V/V): Undetermined

18. Explosion lower limit (%, V/V) : Undetermined

19. Solubility: Soluble in ether, ethanol and water.

Toxicological data

None

Ecological data

This substance is slightly hazardous to water.

Molecular structure data

1. Molar refractive index: 31.36

2. Molar volume (cm³/mol): 122.5

3. Isotonic specific volume (90.2K ): 290.0

4. Surface tension (dyne/cm): 31.3

5. Dielectric constant:

6. Dipole moment (10^-24cm³):

7. Polarizability: 12.43

Compute chemical data

1. Hydrophobic parameter calculation reference value (XlogP): 1.6

2. Number of hydrogen bond donors: 1

3. Number of hydrogen bond acceptors: 2

4. Number of rotatable chemical bonds: 3

5. Number of tautomers:

6.Topological molecular polar surface area (TPSA): 37.3

7, Number of heavy atoms: 8

8, Surface charge: 0

9, Complexity: 78.6

10. Number of isotope atoms: 0

11. Number of determined atomic stereocenters: 0

12. Number of uncertain atomic stereocenters: 1

13. The number of determined stereocenters of chemical bonds: 0

14. The number of uncertain stereocenters of chemical bonds: 0

15. The number of covalent bond units: 1

Properties and stability

1. Avoid contact with oxidants and alkali.

2. Exist in flue-cured tobacco leaves, burley tobacco leaves, oriental tobacco leaves, and mainstream smoke.

3. Found in cheese.

4. It is the characteristic aroma component of oriental tobacco leaves.

Storage method

Stored in a cool, ventilated warehouse. Keep away from fire and heat sources. They should be stored separately from oxidants and strong alkali, and avoid mixed storage. Equipped with the appropriate variety and quantity of fire equipment. The storage area should be equipped with emergency release equipment and suitable containment materials.

Synthesis method

1. Dissolve 200g potassium hydroxide in 200ml water, stir and heat, add dropwise 200g sec-butyldiethylmalonate, the saponification reaction is exothermic, and the reaction solution refluxes steadily for 2 hours. Then dilute with 200 ml of water and evaporate the ethanol generated by saponification. After the remaining reaction product was cooled, 320g of concentrated sulfuric acid and 450ml of water were added, and the mixture was refluxed for 3 hours. The generated organic acid is distilled off and purified by fractionation to obtain 66-69g of 3-methylpentanoic acid, with a yield of 62%-65%.

2. Tobacco: OR, 26, 44, 49; FC, 9, 18; BU, OR, 18; BU, 9; OR, 41; FC, BU, OR, 40; BU, 26 .

3. Preparation method:

In a reaction bottle equipped with a stirrer and a reflux condenser, add 200 mL of water and 200 g of potassium hydroxide, stir and dissolve. Slowly add 200g (0.92mol) of diethyl sec-butylmalonate (2), and reflux the reaction system for 3 hours. Add 200 mL of water and distill. Approximately 200 mL of liquid is evaporated to remove the ethanol generated during the reaction. Slowly add cold olefinic acid composed of 320g sulfuric acid and 450mL water to the reaction solution. After the addition was completed, the reaction was refluxed for 3 hours. Then steam distillation is carried out until no oil is distilled out. The water in the elution liquid can be poured into the reaction bottle in batches, until about 100mL of water remains. The organic layer was separated, and the aqueous layer was extracted twice with diethyl ether. Combine the oil layer and the ether layer, evaporate the ether, then add an equal volume of benzene, use the characteristics of benzene and water to form an azeotrope to remove the water, and finally distill, collect the fractions between 193 and 196°C to obtain 3-methyl Valeric acid (1) 68g, yield 64%. ^[1]

Purpose

1. Used in organic synthesis.