| | Identification | More |  | [Name] 
 3,5-DIMETHYLISOXAZOLE-4-CARBOXYLIC ACID
 |  | [CAS] 
 2510-36-3
 |  | [Synonyms] 
 3,5-DIMETHYL-4-ISOXAZOLECARBOXYLIC ACID
 3,5-DIMETHYLISOXASOLE-4-CARBOXYLIC ACID
 3,5-DIMETHYLISOXAZOLE-4-CARBOXYLIC ACID
 AKOS PAO-1555
 BUTTPARK 27\08-43
 RARECHEM AL BO 0995
 TIMTEC-BB SBB004158
 4-Isoxazolecarboxylic acid, 3,5-dimethyl-
 3,5-DIMETHYLISOXAZOLE-4-CARBOXYLIC ACID, PURISS, 98%
 3,5-Dimethylisoxazole-4-carboxylic acid ,98%
 |  | [EINECS(EC#)] 
 219-724-5
 |  | [Molecular Formula] 
 C6H7NO3
 |  | [MDL Number] 
 MFCD00051657
 |  | [Molecular Weight] 
 141.12
 |  | [MOL File] 
 2510-36-3.mol
 | 
 | Safety Data | Back Directory |  | [Hazard Codes ] 
 Xi,Xn
 |  | [Risk Statements ] 
 R20/21/22:Harmful by inhalation, in contact with skin and if swallowed .
 |  | [Safety Statements ] 
 S24/25:Avoid contact with skin and eyes .
 S36:Wear suitable protective clothing .
 |  | [WGK Germany ] 
 3
 
 |  | [Hazard Note ] 
 Irritant
 |  | [HazardClass ] 
 IRRITANT
 |  | [HS Code ] 
 29349990
 | 
 | Raw materials And Preparation Products | Back Directory |  | [Raw materials] 
 Sodium hydroxide-->Phosphorus oxitrichloride-->Chloroform-->Triethylamine-->Benzene-->Ethyl acetoacetate-->Pyrrolidine-->Nitroethane-->3,4,5-trimethyloxazole-->(3,5-DIMETHYL-4-ISOXAZOLYL)METHANOL-->4-(CHLOROMETHYL)-3,5-DIMETHYLISOXAZOLE-->ETHYL 3,5-DIMETHYLISOXAZOLE-4-CARBOXYLATE-->3,5-Dimethylisoxazole
 |  | [Preparation Products] 
 4-Isoxazolecarboxamide,N,N,3,5-tetramethyl-(9CI)-->4-Isoxazolecarboxylicacid,3,5-dimethyl-,methylester(9CI)
 | 
 | Hazard Information | Back Directory |  | [Chemical Properties] 
 light beige powder
 |  | [Synthesis] 
 
 General procedure for the synthesis of 3,5-dimethylisoxazole-4-carboxylic acid from ethyl 3,5-dimethylisoxazole-4-carboxylate: to a mixture of ethyl 3,5-dimethyl-4-isoxazolecarboxylate (2.4 g, 14 mmol) in a solution of tetrahydrofuran (THF, 8 mL) and methanol (MeOH, 8 mL), an aqueous solution of 5 N sodium hydroxide (NaOH) (8.5 mL ). The reaction mixture was stirred at room temperature for 8 hours. Upon completion of the reaction, the solvent was removed by distillation under reduced pressure, followed by acidification with 6 N aqueous hydrochloric acid (HCl) to pH = 2. The precipitated white solid product was filtered, washed with water, and dried to afford 3,5-dimethylisoxazole-4-carboxylic acid (2.1 g, 94.0% yield). The structure of the product was confirmed by 1H NMR (300 MHz, CDCl3): δ 2.72 (s, 3H), 2.49 (s, 3H). |  | [References] 
 [1] Bioorganic and Medicinal Chemistry Letters,  2018,  vol. 28,  # 17,  p. 2879 - 2884
 [2] Justus Liebigs Annalen der Chemie,  1893,  vol. 277,  p. 174
 [3] Journal of the American Chemical Society,  1967,  vol. 89,  p. 5461 - 5462
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