3-METHYLISOXAZOLE-5-CARBOXYLIC ACID

3-METHYLISOXAZOLE-5-CARBOXYLIC ACID Property

Melting point:

210-211 °C

Boiling point:

307.8±22.0 °C(Predicted)

Density 

1.348±0.06 g/cm3(Predicted)

RTECS 

NY2560000

storage temp. 

Keep in dark place,Sealed in dry,Store in freezer, under -20°C

form 

Solid

pka

2.36±0.10(Predicted)

color 

White to Almost white

InChI

InChI=1S/C5H5NO3/c1-3-2-4(5(7)8)9-6-3/h2H,1H3,(H,7,8)

InChIKey

HXIYCKAAQPHZBM-UHFFFAOYSA-N

SMILES

O1C(C(O)=O)=CC(C)=N1

Safety

Hazard Codes 

Xi

Risk Statements 

43

Safety Statements 

36/37

Hazard Note 

Harmful

HazardClass 

IRRITANT

HS Code 

2934999090

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.

3-METHYLISOXAZOLE-5-CARBOXYLIC ACID Chemical Properties,Usage,Production

Uses

3-Methylisoxazole-5-carboxylic acid is a carboxylic acid derivative, mainly used as a pharmaceutical intermediate.

Application

3-Methylisoxazole-5-carboxylic acid is an organic intermediate that can be prepared by first cyclizing acetaldehyde oxime and propargyl alcohol to prepare (3-methylisoxazole-5-yl)methanol, and then oxidizing it to obtain 3-methylisoxazole-5-carboxylic acid.

Synthesis

General procedure for the synthesis of 3-methylisoxazole-5-carboxylic acid from methyl 3-methyl-5-isoxazolecarboxylate: To a round bottom flask equipped with a magnetic stirrer was added a solution of methyl 3-methyl-5-isoxazolecarboxylate (900 mg, 5.8 mmol) in tetrahydrofuran (2.0 mL). Subsequently, a solution of sodium hydroxide (465 mg, 11.6 mmol) in water (2 mL) was added dropwise to the reaction system and methanol (4 mL) was added. The reaction mixture was stirred at room temperature for 18-20 hours under argon protection. Upon completion of the reaction, the mixture was transferred to a partition funnel and the pH was adjusted to 2 with 1 N hydrochloric acid solution. the aqueous phase was extracted with ethyl acetate (3 x 35 mL), the organic phases were combined and washed with saturated brine (50 mL), dried over anhydrous magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure to afford 3-methylisoxazole-5-carboxylic acid as a white solid (660 mg, 90% yield). The obtained product did not need further purification and could be used directly in the next reaction.

References

[1] Angewandte Chemie - International Edition, 2016, vol. 55, # 29, p. 8353 - 8357
[2] Angew. Chem., 2016, vol. 128, # 29, p. 8493 - 8497,5
[3] Patent: WO2006/91674, 2006, A1. Location in patent: Page/Page column 79
[4] European Journal of Medicinal Chemistry, 1992, vol. 27, # 6, p. 581 - 593