ChemicalBook CAS DataBase List 3,5-DIMETHYLISOXAZOLE-4-CARBOXYLIC ACID

3,5-DIMETHYLISOXAZOLE-4-CARBOXYLIC ACID synthesis

5synthesis methods

Product Name:3,5-DIMETHYLISOXAZOLE-4-CARBOXYLIC ACID
CAS Number:2510-36-3
Molecular formula:C6H7NO3
Molecular Weight:141.12

ETHYL 3,5-DIMETHYLISOXAZOLE-4-CARBOXYLATE

17147-42-1

2510-36-3

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).

17147-42-1 Synthesis

17147-42-1
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2510-36-3
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$5.00/1g

Yield: 94%

Reaction Conditions:

with sodium hydroxide in tetrahydrofuran;methanol;water at 20; for 8 h;

Steps:

1.6. 3,5-dimethylisoxazole-4-carboxylic acid (13)
To a solution of ethyl 3,5-dimethyl-4-isoxazolecarboxylate (2.4 g, 14 mmol) in THF (8 mL) and MeOH (8 mL) was added 5N aqueous NaOH (8.5 mL). The reaction was stirred at room temperature for 8 h. The reaction mixture was removed under reduced pressure and acidified with 6 N aqueous HCl to pH=2. The precipitated product was filtered, washed with water, and dried to afford 9 (2.1 g, 94.0%) as a white solid.¹H NMR (300 MHz, CDCl₃) δ 2.72 (s, 3H), 2.49 (s, 3H).

References:

Qiu, Rongmao;Luo, Guoshun;Li, Xinyu;Zheng, Fan;Li, Haolin;Zhang, Jin;You, Qidong;Xiang, Hua [Bioorganic and Medicinal Chemistry Letters,2018,vol. 28,# 17,p. 2879 - 2884] Location in patent:supporting information