Polyether_Polyether Polyol Knowledge 2,4-Dioxopentanoic acid ethyl ester

2,4-Dioxopentanoic acid ethyl ester

2,4-dioxopentanoic acid ethyl ester structural formula

Structural formula

Business number 06GQ
Molecular formula C7H10O4
Molecular weight 158.15
label

Ethyldiazole ester,

Ethyl acetylacetonate,

Acetone ethyl oxalate,

Acetylacetonate,

Ethyl acetonoxalate,

CH3COCH2COCOOC2H5

Numbering system

CAS number:615-79-2

MDL number:MFCD00009124

EINECS number:210-447-5

RTECS number:None

BRN number:607062

PubChem number:24853912

Physical property data

1. Physical property data

1. Melting point (ºC): 16-18ºC

2. Boiling point (ºC, normal pressure): 101-103 °C12 mm Hg(lit .)

3. Density: 1.126 g/mL at 25 °C(lit.

4. Refractive index: n20/D 1.474(lit .)

5. Flash point (ºC): 230 °F

Toxicological data

None

Ecological data

3. Ecological data:

1. Other harmful effects: This substance may be harmful to the environment, and special attention should be paid to water bodies.

Molecular structure data

5. Molecular property data:

1. Molar refractive index: 36.31

2. Molar volume (cm3/mol): 141.8

3. Isotonic specific volume (90.2K): 345.5

4. Surface tension (dyne/cm): 35.2

5. Polarizability (10-24cm3): 14.39

Compute chemical data

1. Reference value for hydrophobic parameter calculation (XlogP): 0.2

2. Number of hydrogen bond donors: 0

3. Number of hydrogen bond acceptors: 4

4. Number of rotatable chemical bonds: 5

5. Number of tautomers: 5

6. Topological molecule polar surface area 60.4

7. Number of heavy atoms: 11

8. Surface charge: 0

9. Complexity: 183

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

Properties and stability:

The product may not decompose under normal temperature and pressure.

Storage method

Storage:

Seal the container and store it in a sealed main container in a cool, dry place.

Synthesis method

1. Production method: Obtained from the condensation of oxalic acid diester and acetone (Kirschner reaction). Add sodium methoxide dropwise into diethyl oxalate and acetone at 40-45°C, keep warm for 1 hour, and add concentrated sulfuric acid dropwise to pH=3.5 while cooling. Extract with benzeneThe reactants and extracts were distilled under reduced pressure after benzene was removed. Collect the 130-132°C (4.93kPa) fraction to obtain the product ethyl acetylacetonate. 2. Preparation method: In a reaction flask equipped with a stirrer, reflux condenser and dropping funnel , add 2L of absolute ethanol, and add 63g (2.7mol) of metallic sodium in batches while stirring. After all the sodium has reacted, cool to room temperature. Add dropwise a mixture of 365g (2.5mol) of diethyl oxalate (3) and 145g (2.5mol) of acetone (2), and finish adding in about 3 hours. After the addition is completed, raise the temperature to 40°C and continue stirring for 1 hour to form a yellow viscous substance. Cool, filter with suction, and wash with ethanol to obtain sodium salt (4) . Add the sodium salt to 1.3g of ice water, slowly add it to the pre-frozen dilute sulfuric acid (prepared with 100mL concentrated sulfuric acid and 200mL water) while stirring, control the temperature of the reaction solution at 0~5°C, adjust to pH 3~4, and continue stirring for 10 minutes , until the yellow sodium salt disappears. Extract with benzene (300mL×3), combine the extracts, and wash with water. Benzene was recovered by distillation under normal pressure, and then distilled under reduced pressure to collect the fraction at 117~121℃/308kPa to obtain 240g of ethyl acetylacetonate (1), with a yield of 61%. Note: ① A white precipitate is formed in the early stage of the reaction, then gradually turns yellow, further deepens, and finally turns yellow, and the reaction system gradually thickens. ②Suction filtration is very slow, and finally centrifugation is used. ③The product has poor stability and will decompose on its own during storage. [1]

Purpose

Usage: Intermediate of pharmaceutical sulfonamides.

This article is from the Internet, does not represent the position of Toluene diisocyanate reproduced please specify the source.https://www.polyether-factory.com/archives/20190

author:

Previous article
Next article
Contact Us

Contact us

+86 - 152 2121 6908

Online consultation: QQ交谈

E-mail: sales@newtopchem.com

Working hours: Monday to Friday, 9:00-17:30, closed on holidays
Follow wechat
Scan wechat and follow us

Scan wechat and follow us

Follow Weibo
Back to top
Home
E-mail
Products
Search