3-甲基异恶唑-5-羧酸甲酯是一种杂环化合物,在有机合成中用作试剂,并在其他化合物的合成中作为中间体,常用于实验室中。
制备3-甲基异恶唑-5-羧酸甲酯可通过氯甲酸甲酯与3-甲基异恶唑-5-酮反应制得。此外,这种化合物与亚硝酸盐反应可生成次氯酸盐,可用作漂白剂或消毒剂;同时,它也可与酰胺、腈和氧化物分别反应生成叔胺和肟。
中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
3-甲基异恶唑-5-甲酸 | 3-methyl-5-isoxazolecarboxylic acid | 4857-42-5 | C5H5NO3 | 127.1 |
中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | 3-(methoxymethyl)isoxazole-5-carboxylic acid | 1076245-91-4 | C6H7NO4 | 157.126 |
—— | methyl 4-iodo-3-methylisoxazole-5-carboxylate | 1092301-44-4 | C6H6BrNO3 | 220.023 |
3-甲基异唑-5-甲醇 | 3-methyl-5-isoxazolemethanol | 14716-89-3 | C5H7NO2 | 113.116 |
3-甲基异恶唑-5-甲醛 | 3-methylisoxazole-5-carbaldehyde | 70753-36-5 | C5H5NO2 | 111.1 |
The lithiation of various methyl substituted isoxazoles, isothiazoles, pyrazoles, oxadiazoles, and thiadiazoles using n-butyllithium has been studied. Three types of reactions, namely, lateral lithiation, ring cleavage, and addition of butyllithium to the ring, have been found. 3,5-Dimethylisoxazole, 3-phenyl-5-methylisoxazole, 3,4-dimethyl-1,2,5-oxadiazole, 2,5-dimethyl-1,3,4-thiadiazole, 3-phenyl-5-methyl-1,2,4-oxadiazole, and 3,5-dimethyl-1,2,4-thiadiazole all undergo lateral lithiation to give the respective acetic acids after carboxylation. 1-Methyl-3,5-disubstituted pyrazoles form the 1-lithiomethyl derivatives, while 1-phenyl-3,5-disubstituted pyrazoles are converted to the 1-ortholithiophenyl-3,5-disubstituted pyrazoles. 4-Methylisothiazole is lithiated mainly at C-5, but also suffers ring cleavage to form 1-n-butylthio-2-cyanoprop-1-ene. Heteroaromatic compounds containing an N—S bond, such as 3,4-dimeth yl-1,2,5-thiadiazole, 4-methyl-5-phenyl-1,2,3-thiadiazole, and 3,5-dimethylisothiazole, undergo nucleophilic attack at sulfur with resulting ring cleavage. 3,5-Dimethylisothiazole produces 2-n-butylthiopent-2-en-4-one. 3-Methyl-5-phenyl-1,2,4-oxadiazole gave 3-methyl-5-phenyl-5-n-butyl-1,2,4-dihydroöxadiazole by addition to the azomethine bond. The results of these lithiations are discussed. 3-Methyl-5-lithiomethylisoxazole was converted to various derivatives. Nuclear magnetic resonance spectral analysis was used to establish the identity of the products.