18718-84-8Relevant articles and documents
A 3 - substituted - 4 - isoxazole carboxylic acid synthesizing method
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Paragraph 0056-0058, (2017/08/23)
The invention relates to a synthesis method of high-purity and high-regioselectivity 3-substituted-4-isoxazole carboxylic acid. The method has the advantages of simplicity and easiness in operation, mild reaction and high yield and can solve the technical problems of harsh reaction conditions, generation of isomers, difficulty in separation, low total yield and difficulty in large-scale production of the existing preparation method. The preparation steps are as follows: taking 3-substituted-3-oxopropionate (I) as a starting raw material, and performing cyclization with hydroxylamine hydrochloride and an alkali in water to prepare 3-substituted-4-isoxazole-5-ketone (II); performing acetalization on the compound (II) and N, N-dimethylformamide dimethyl acetal to prepare 4-dimethylaminomethylene-3-substituted-4-hydrogen-isoxazol-5-ketone (III); performing ring opening by hydrolysis of lactone on the compound (III) in alkaline conditions and re-closing a ring; and acidifying to obtain the 3-substituted-4-isoxazole carboxylic acid. The method for the 3-substituted-4-isoxazole carboxylic acid, provided by the invention, is used for development and large-scale preparation.
Isoxazolecarboxamide derivatives
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Example 15, (2010/01/31)
The invention relates to novel N-(substituted phenyl)-N′-[ω-(3-substituted phenyl-4-isoxazolecarbonylamino)alkyl]piperazines, their N-oxides, and pharmaceutically acceptable salts thereof. The compounds are endowed with enhanced selectivity for alpha1-adrenergic receptors and a low activity in lowering blood pressure. The compounds are useful in the treatment of obstructive syndromes of the lower urinary tract, including benign prostatic hyperplasia (BPH), and in the treatment of lower urinary tract symptoms (LUTS) and neurogenic lower urinary tract dysfunction (NLUTD), and other conditions.
