63364-70-5

Basic information

• Product Name: 3-methylbuta-1,2-dien-1-one
• CAS NO: 63364-70-5
• Molecular Formula: C₅H₆O
• Molecular Weight: 82.1005
• Mol File: 63364-70-5.mol
• Article Data: 3

Chemical Properties

• Boiling Point: 90.1°C at 760 mmHg
• Flash Point: 5.3°C
• Density: 0.778g/cm³
• Vapor Pressure: 57mmHg at 25°C
• Refractive Index: 1.393
• CAS DataBase Reference: 3-methylbuta-1,2-dien-1-one(CAS DataBase Reference)
• NIST Chemistry Reference: 3-methylbuta-1,2-dien-1-one(63364-70-5)
• EPA Substance Registry System: 3-methylbuta-1,2-dien-1-one(63364-70-5)

Safety Data

• Hazardous Substances Data: 63364-70-5(Hazardous Substances Data)

Upstream product

• 2231-66-5 2,2-dimethyl-5-(propan-2-ylidene)-1,3-dioxane-4,6-dione 
• 128728-65-4 4-Diazo-2,2-dimethyl-8-oxa-bicyclo[3.2.1]oct-6-en-3-one 
• 1025928-21-5 isopropylidenemalonate di-t-butylperester 

Downstream Products

• 503-17-3 dimethylacetylene 
• 201230-82-2 carbon monoxide 
• 924-50-5 Methyl 3,3-dimethylacrylate 

Relevant articles and documents

Photochemical generation and matrix-isolation detection of dimethylvinylidene

We report the spectroscopic characterization of dimethylvinylidene, (CH3)2C=C:, generated within an argon matrix at 14 K from a bisperoxyester precursor. The carbene was identified by comparison of the experimental IR spectrum with vibrational frequencies computed at the B3LYP/6-31G(d) level. Chemical trapping of the carbene within a 9% CO/Ar matrix to form dimethylpropadienone supports this analysis. Additional products produced during photolysis were identified by comparison to the appropriate computed vibrational frequencies. The potential energy surface of dimethylvinylidene and its intramolecular rearrangement products, 2-butyne and methylcyclopropene, were also investigated computationally at the B3LYP/6-31G(d) level. A spin-state analysis of this carbene using a variety of computational methods (CCSD(T), B3LYP, MP2) indicates the singlet state is more stable than the triplet by ～45 kcal mol-1. We anticipate the bisperoxyester precursor used here will be a convenient and general way for initiating future studies of alkylvinylidenes under matrix-isolation conditions.

Gasphasen-Reaktionen, 22. Thermische Erzeugung von C4H4O: Vinylketen und Ethylidenketen

Thermal HX elimination from unsatured carboxylic acid derivatives CH3-RC=CH-COX represents another method to generate the short-lived isomers C4H3RO with R = H, CH3 in the gas phase.The temperature-dependent changes of amounts of products in the heated flow system are analyzed by photoelectron spectra: based on MNDO calculations and in accordance with literature data, the vinylketene structure CH2=CR-HC=C=O is assigned to the thermolysis product.The isomeric alkylideneketenes H3C-RC=C=C=O with R = H, CH3 are produced in the 760 K short-path pyrolysis of alkylidenemalonates and rearrange on prolonged residence time in the heating zone into the thermodynamically more stable vinylketene derivatives.