50421-80-2

Basic information

• Product Name: 4-hydroxy-3-methylbut-3-en-2-one
• CAS NO: 50421-80-2
• Molecular Formula: C₅H₈O₂
• Molecular Weight: 100.1158
• Mol File: 50421-80-2.mol

Chemical Properties

• Boiling Point: 187.6°C at 760 mmHg
• Flash Point: 71.9°C
• Density: 1.01g/cm³
• Vapor Pressure: 0.174mmHg at 25°C
• Refractive Index: 1.45
• CAS DataBase Reference: 4-hydroxy-3-methylbut-3-en-2-one(CAS DataBase Reference)
• NIST Chemistry Reference: 4-hydroxy-3-methylbut-3-en-2-one(50421-80-2)
• EPA Substance Registry System: 4-hydroxy-3-methylbut-3-en-2-one(50421-80-2)

Safety Data

• Hazardous Substances Data: 50421-80-2(Hazardous Substances Data)

Upstream product

• 107-31-3 Methyl formate 
• 78-93-3 butanone 
• 638-49-3 n-pentyl formate 
• 109-94-4 formic acid ethyl ester 

Downstream Products

• 72716-80-4 2-hydroxy-5,6-dimethylnicotinonitrile 
• 91138-00-0 5-methyl-1-phenyl-1H-pyrazole-4-carboxylic acid 
• 77169-11-0 3-Methyl-1-phenyl-1H-pyrazole-4-carboxylic acid 
• 938-75-0 3,4-dimethyl-1H-pyrrole-2-carboxylic acid ethyl ester 
• 116436-00-1 3,4-dimethyl-1-phenyl-1H-pyrazole 
• 2820-37-3 3,4-dimethyl-1H-pyrazole 
• 1193-74-4 4,5-dimethylpyrimidin-2-amine 

Relevant articles and documents

Facile synthesis of 2,3,7,8-tetramethyl-2,2′-dipyrrin trifluoroacetate and its X-ray crystal structure

3,4-Dimethyl-1H-pyrrole-2-carboxylic acid was converted to 2,3,7,8-tetramethyl-2,2′-dipyrrin by the action of trifluoroacetic acid and ethyl orthoformate. A crystal of the dipyrrin was grown from dichloromethane-n-hexane and an X-ray crystallographic structure of its trifluoroacetate salt was determined.

Synthesis of substituted benzenes from α-methylene ketones

A new general method for the synthesis of substituted benzenes from cyclic ketones having active methylene groups via the corresponding hydroxymethylene ketones and enamino-ketones has been developed. Formylation of these ketones with ethyl formate followed by enamination with pyrrolidine produces enamino-ketones which on reaction with threefold excess of malononitrile in boiling benzene in the presence of ammonium acetate in acetic acid gives the substituted benzenes in good yield. The reaction has been extended to aliphatic and aromatic ketones having active methylene groups to give substituted benzenes and biphenyls, respectively.

Reaction of Sulfene and Dichloroketene with Open-chain N,N-Disubstituted α-Aminomethyleneketones. Synthesis of 4-Dialkylamino-3,4-dihydro-5,6-dimethyl-1,2-oxathiin 2,2-Dioxides and of 6,(5)(Di)alkyl-3-chloro-4-methylphenylamino-2H-pyran-2-ones

Cycloaddition of sulfene to N,N-disubstituted 4-amino-3-methyl-3-buten-2-ones(III) occurred in fair to good yield only in the case of aliphatic N-substitution to give 4-dialkylamino-3,4-dihydro-5,6-dimethyl-1,2-oxathiin 2,2-dioxides, wheras N,N-disubstituted 1-amino-1-penten-3-ones (II) did not react at all.Cycloaddition of dichloroketene to II, III and N,N-disubstituted 4-amino-3-buten-2-ones occurred only in the case of the methylphenylamino derivative, giving in good to moderate yield 6,(5)(di)alkyl-3,3-dichloro-3,4-dihydro-4-methylphenylamino-2H-pyran-2-ones, whichwere dehydrochlorinated with DBN to 6,(5)(di)alkyl-3-chloro-4-methylphenylamino-2H-pyran-2-ones.