81784-70-5

Basic information

• Product Name: 5-Ethyl-2-phenyl-isoxazol-3-one
• Synonyms: 5-Ethyl-2-phenyl-isoxazol-3-one
• CAS NO: 81784-70-5
• Molecular Weight: 189.214
• Mol File: 81784-70-5.mol

Chemical Properties

• CAS DataBase Reference: 5-Ethyl-2-phenyl-isoxazol-3-one(CAS DataBase Reference)
• NIST Chemistry Reference: 5-Ethyl-2-phenyl-isoxazol-3-one(81784-70-5)
• EPA Substance Registry System: 5-Ethyl-2-phenyl-isoxazol-3-one(81784-70-5)

Safety Data

• Hazardous Substances Data: 81784-70-5(Hazardous Substances Data)

Upstream product

• 66696-76-2 5-(1-hydroxypropylidene)-2,2-dimethyl-[1,3]dioxane-4,6-dione 
• 81784-64-7 3-Oxo-pentanoic acid hydroxy-phenyl-amide 
• 64074-05-1 2,2-dimethyl-5-propanoyl-1,3-dioxan-4,6-dione 

Relevant articles and documents

Meldrum's Acid in Organic Synthesis. VI. Synthesis of 2-Substituted Indoles from Acyl Meldrum's Acids and Phenylhydroxylamine via Sigmatropic Rearrangement

Phenylhydroxylamine (13) oxalate was quite easily acylacetylated by heating with an equimolar amount of acyl Meldrum's acid (4) in acetonitrile to give an N-acylacetylphenylhydroxylamine (14) in high yield.When 14 was treated with another equimolar amount of the same 4 in refluxing toluene, a series of reactions, O-acylacetylation, 1-aza-1'-oxasigmatropic rearrangement, decarboxylation, dehydrative cyclization, and deacylation, occured consecutively to give a 2-substituted indole (16) in fair yield, though sometimes accompanied by the formation of a 5-substituted 4-isoxazolin-3-one (17).N-Benzoyl, N-acetyl, and N-benzyloxycarbonyl derivatives of phenylhydroxylamine (18) were treated with phenylacetyl Meldrum's acid (4i) in refluxing benzene containing copper powder to give readily rearranged ortho alkylation products (19), which were converted to the corresponding N-acyl-2-benzylindoles (20) by treatment with hydrochloric acid in boiling ethanol or with anhydrous p-toluenesulfonic acid in benzene at room temperature.Keywords - acyl Meldrum's acid; phenylhydroxylamine; N-acylacetylphenylhydroxylamine; 2-substituted indole; 1-aza-1'-oxasigmatropic rearrangement; acid-catalyzed cyclization

MELDRUM'S ACID IN ORGANIC SYNTHESIS 3. SYNTHESIS OF 2-SUBSTITUTED INDOLES FROM PHENYLHYDROXYLAMINE

Treatment of phenylhydroxylamine oxalate with acyl Meldrum's acids in boiling acetonitrile readily gave N-acylacetylphenylhydroxylamines, which were converted to 2-substituted indoles by another treatment with acyl Meldrum's acids in refluxing toluene.N-B

MELDRUM'S ACID IN ORGANIC SYNTHESIS 4. SYNTHESIS OF 5-SUBSTITUTED 2-PHENYLISOXAZOLIN-3-ONES FROM N-ACYLACETYLPHENYLHYDROXYLAMINES

When N-acylacetylphenylhydroxylamines, readily prepared from phenylhydroxylamine and acyl Meldrum's acids (5-acyl-2,2-dimethyl-1,3-dioxane-4,6-diones) were refluxed in benzene in the presence of a catalytic amount of p-toluenesulfonic acid, an acid-cataly