ChemicalBook > CAS DataBase List > 5-Methyl-4-isoxazolecarboxylic acid
5-Methyl-4-isoxazolecarboxylic acid
- Product Name
- 5-Methyl-4-isoxazolecarboxylic acid
- CAS No.
- 42831-50-5
- Chemical Name
- 5-Methyl-4-isoxazolecarboxylic acid
- Synonyms
- 5-METHYLISOXAZOLE-4-CARBOXYLIC ACID;TIMTEC-BB SBB005909;Leflunomide Impurity D;Lefluonamide Impurity D;LeflunoMide EP IMpurity D;Leflunomide impurities1343;Methylisoxazole-4-carboxylic;5-Methyl-4-isoxazolecarboxyl;5-METHYLISOXAZOLE-4-CARBOXYLIC;5-methylisoxazole-4-formic acid
- CBNumber
- CB8342928
- Molecular Formula
- C5H5NO3
- Formula Weight
- 127.1
- MOL File
- 42831-50-5.mol
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5-Methyl-4-isoxazolecarboxylic acid Property
- Melting point:
- 144-148 °C(lit.)
- Boiling point:
- 308.3±22.0 °C(Predicted)
- Density
- 1.348±0.06 g/cm3(Predicted)
- storage temp.
- Sealed in dry,Room Temperature
- solubility
- DMSO (Slightly), Methanol (Slightly)
- form
- Solid
- pka
- 2.85±0.25(Predicted)
- color
- White to Pale Brown
- BRN
- 116000
- CAS DataBase Reference
- 42831-50-5(CAS DataBase Reference)
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Safety
- Hazard Codes
- Xi,F
- Risk Statements
- 36/37/38-37/38-36-10
- Safety Statements
- 22-26-36/37/39-36-16
- WGK Germany
- 3
- HazardClass
- IRRITANT
- HS Code
- 29349990
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Hazard and Precautionary Statements (GHS)
- Symbol(GHS)
-
- Signal word
- Warning
- Hazard statements
-
H315Causes skin irritation
H319Causes serious eye irritation
H335May cause respiratory irritation
- Precautionary statements
-
P261Avoid breathing dust/fume/gas/mist/vapours/spray.
P304+P340IF INHALED: Remove victim to fresh air and Keep at rest in a position comfortable for breathing.
P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.
P405Store locked up.
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N-Bromosuccinimide Price
Sigma-Aldrich
- Product number
- 633771
- Product name
- 5-Methylisoxazole-4-carboxylic acid
- Purity
- 97%
- Packaging
- 10g
- Price
- $232
- Updated
- 2025/07/31
Sigma-Aldrich
- Product number
- 633771
- Product name
- 5-Methylisoxazole-4-carboxylic acid
- Purity
- 97%
- Packaging
- 1g
- Price
- $34.7
- Updated
- 2023/06/20
TCI Chemical
- Product number
- M1740
- Product name
- 5-Methylisoxazole-4-carboxylic Acid
- Purity
- >98.0%(T)(HPLC)
- Packaging
- 5g
- Price
- $17
- Updated
- 2025/07/31
TCI Chemical
- Product number
- M1740
- Product name
- 5-Methylisoxazole-4-carboxylic Acid
- Purity
- >98.0%(T)(HPLC)
- Packaging
- 25g
- Price
- $56
- Updated
- 2025/07/31
TRC
- Product number
- M315000
- Product name
- 5-Methylisoxazole-4-carboxylic acid
- Packaging
- 1g
- Price
- $50
- Updated
- 2021/12/16
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5-Methyl-4-isoxazolecarboxylic acid Chemical Properties,Usage,Production
Chemical Properties
Cream to brown Solid
Uses
5-Methylisoxazole-4-carboxylic Acid (Leflunomide EP Impurity D) is an intermediate for synthesis of Leflunomide (L322750). Herbicidal activities towards Digitaria ciliaris.
Flammability and Explosibility
Non flammable
Synthesis
51135-73-0
42831-50-5
Example 4 Preparation of 5-methylisoxazole-4-carboxylic acid To a two-necked flask equipped with a mechanical stirrer and a horizontal condenser for distillation were added 40.0 g of crude ethyl 5-methyl-4-isoxazolecarboxylate and 44 g of 60% sulfuric acid solution. The mixture was heated to 85°C while the ethanol generated from the reaction was continuously distilled. After 4 hours of reaction, thin layer chromatography (TLC) analysis showed complete disappearance of spots of ester compounds. After cooling the reaction mixture to room temperature, the solid product (16.5 g) was collected by filtration. The filtrate was retained for a second product collection at room temperature. The resulting crude acid was dissolved in 60 mL of 2% acetic acid-toluene mixed solvent and crystallized to give 5-methylisoxazole-4-carboxylic acid (9.5 g) of about 99.9% purity. The crystallized mother liquor was retained for subsequent batch processing. The crystallization process was performed as follows: the crude acid was added to 2% acetic acid-toluene solvent mixture and heated for 30 minutes until dissolved. Separate and remove the brown oil from the bottom of the flask. The upper clear organic phase was carefully transferred to another container and left to crystallize.
References
[1] Patent: US2003/139606, 2003, A1
[2] Letters in Drug Design and Discovery, 2016, vol. 13, # 9, p. 912 - 920
[3] Journal of Heterocyclic Chemistry, 1991, vol. 28, # 2, p. 453 - 457
[4] Yakugaku Zasshi, 1959, vol. 79, p. 836
[5] Chem.Abstr., 1960, p. 1493
5-Methyl-4-isoxazolecarboxylic acid Preparation Products And Raw materials
Raw materials
Preparation Products
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View Lastest Price from 5-Methyl-4-isoxazolecarboxylic acid manufacturers
WUHAN FORTUNA CHEMICAL CO., LTD
- Product
- 5-Methyl-4-isoxazolecarboxylic acid 42831-50-5
- Price
- US $0.00-0.00/Kg/Drum
- Min. Order
- 1KG
- Purity
- 99%min
- Supply Ability
- 1000KGS
- Release date
- 2021-11-08
Shaanxi Dideu New Materials Co. Ltd
- Product
- 5-Methyl-4-isoxazolecarboxylic acid 42831-50-5
- Price
- US $0.00/kg
- Min. Order
- 1kg
- Purity
- 99%
- Supply Ability
- 10000KGS
- Release date
- 2025-02-20
Shaanxi Dideu New Materials Co. Ltd
- Product
- 5-Methyl-4-isoxazolecarboxylic acid 42831-50-5
- Price
- US $0.00/kg
- Min. Order
- 1kg
- Purity
- 99%
- Supply Ability
- 10000KGS
- Release date
- 2025-02-25
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