Toluene diisocyanate manufacturer Knowledge Barbituric Acid Barbituric Acid

Barbituric Acid Barbituric Acid

Barbituric acid structural formula

Structural formula

Business number 01ES
Molecular formula C4H4N2O3
Molecular weight 128.09
label

Heterocyclic compounds

Numbering system

CAS number:67-52-7

MDL number:MFCD00006666

EINECS number:200-658-0

RTECS number:CP8000000

BRN number:120502

PubChem number:24847314

Physical property data

1. Properties: White crystalline powder. Strongly acidic. Forms salts when meeting metals.

2. Density (g/mL, 25/4℃): Undetermined

3. Relative vapor density (g/mL, air=1): Undetermined

4. Melting point (ºC): 248 (decomposition)

5. Boiling point (ºC, normal pressure): 260 (decomposition)

6. Boiling point (ºC, 5.2 kPa): Not determined

7. Refractive index: Not determined

8. Flash point (ºC): Not determined

9. Specific rotation (º ): Undetermined

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

11. Vapor pressure (kPa, 25ºC): Undetermined

12. Saturated vapor pressure (kPa, 60ºC): Undetermined

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

14. Critical temperature (ºC): Undetermined

15. Critical pressure (KPa): Undetermined

16. Log value of oil-water (octanol/water) partition coefficient: Undetermined

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

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

19. Solubility: Easily soluble in hot water And dilute acid, soluble in ether, slightly soluble in cold water.

Toxicological data

Acute toxicity: rat oral LD50: >5 mg/kg; mouse intraperitoneal LD50: 505 mg/kg;

Ecological data

General remarks

Water hazard level 1 (German regulations) (self-assessment via list) This substance is extremely hazardous to water.

Do not allow undiluted or large quantities of product to come into contact with groundwater, waterways or sewage systems

Do not discharge materials into the surrounding environment without government permission.

Molecular structure data

1. Molar refractive index: 25.53

2. Molar volume (cm3/mol): 88.0

3. Isotonic specific volume (90.2K ): 232.5

4. Surface tension (dyne/cm): 48.7

5. Polarizability (10-24cm3):10.12

Compute chemical data

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

2. Number of hydrogen bond donors: 2

3. Number of hydrogen bond acceptors: 3

4. Number of rotatable chemical bonds��:0

5. Number of tautomers: 10

6. Topological molecule polar surface area 75.3

7. Number of heavy atoms: 9

8. Surface charge: 0

9. Complexity: 168

10. Number of isotope atoms: 0

11. Determine Number of atomic stereocenters: 0

12. Uncertain number of atomic stereocenters: 0

13. Determined number of chemical bond stereocenters: 0

14 .The number of uncertain chemical bond stereocenters: 0

15. The number of covalent bond units: 1

Properties and stability

Storage method

This product should be kept sealed. This product is lined with polyethylene film bags and is packaged in iron drums or cardboard drums for export. The net weight of each drum is 25kg.

Synthesis method

Obtained from the reaction of diethyl malonate and urea. First, add urea into a reaction tank containing methanol and heat it to reflux to dissolve, then add dried diethyl malonate and sodium methoxide, and reflux for 4-5 hours at 66-68°C. After distilling and recovering the methanol, wait until it is cooled to 40-50℃, add dilute hydrochloric acid to adjust the pH to 1-2. Let cool to room temperature, throw out the crude product, rinse once with distilled water, spin dry to get the crude product, then refine with water and activated carbon, and spin dry to get the finished product. Industrial product barbituric acid is white or pink crystalline powder, which is highly acidic, with a content of more than 98% and a melting point of ≥245°C. Raw material consumption quota: diethyl malonate 1098kg/t, urea 476kg/t, hydrochloric acid (reagent level III) 681kg/t, sodium methoxide (28%) 369kg/t, methanol 1025kg/t.

Purpose

Colorimetric determination of furfurals and polypentosides. Organic Synthesis. Used as organic synthesis raw materials, medicines, plastics and dye intermediates. It is an intermediate for barbiturates, vitamin B12 and other drugs. It can also be used as a polymerization catalyst and for the preparation of benzimidazolone organic pigments. It can also be used as a reagent for the colorimetric determination of uronic aldehydes and polypentosides.

This article is from the Internet, does not represent the position of Toluene diisocyanate reproduced please specify the source.https://www.chemicalchem.com/archives/24263

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