814-78-8

Basic information

• Product Name: Methyl isopropenyl ketone
• Synonyms: 2-Methyl-1-buten-3-one;3-Methyl-3-buten-2-one;3-Methylene-2-butanone;Isopropenyl methyl ketone;Methyl isopropenyl ketone;NSC 24150;Propen-2-yl methyl ketone
• CAS NO: 814-78-8
• Molecular Formula: C₅H₈O
• Molecular Weight: 84.11642
• EINECS: 212-405-1
• Mol File: 814-78-8.mol

Chemical Properties

• Melting Point: -54 °C
• Boiling Point: 98 °C at 760 mmHg
• Flash Point: 11 °C
• Appearance: clear colorless liquid
• Density: 0.816 g/cm³
• Vapor Pressure: 4.314mmHg at 25°C
• Refractive Index: 1.425
• CAS DataBase Reference: Methyl isopropenyl ketone(CAS DataBase Reference)
• NIST Chemistry Reference: Methyl isopropenyl ketone(814-78-8)
• EPA Substance Registry System: Methyl isopropenyl ketone(814-78-8)

Safety Data

• Hazardous Substances Data: 814-78-8(Hazardous Substances Data)

Usage

Uses

Used in Pharmaceutical Industry:
Methyl isopropenyl ketone is used as an intermediate in the synthesis of various pharmaceuticals for its ability to react and form complex organic molecules, contributing to the development of new drugs and medicines.
Used in Flavor and Fragrance Industry:
It serves as a key component in the creation of flavorings and fragrances, enhancing the sensory experience of various consumer products by imparting specific scents and tastes.
Used as a Solvent in Chemical Industry:
Methyl isopropenyl ketone is utilized as a solvent for resins, cellulose esters, and lacquers, due to its capacity to dissolve a wide range of substances, which is essential in the manufacturing process of coatings and adhesives.
Safety Considerations:
Given its flammable nature, Methyl isopropenyl ketone requires careful handling to prevent fire hazards. Moreover, prolonged or repeated exposure to its vapors may lead to respiratory irritation, necessitating proper safety measures during its use in industrial settings.

InChI:InChI=1/C7H12O/c1-6(2)4-5-7(3)8/h4H,5H2,1-3H3

Upstream product

• 19995-85-8 4-chloro-3-methyl-butan-2-one 
• 786730-43-6 3,7-dimethyl-oct-7-ene-2,6-dione 
• 463-51-4 Ketene 
• 431-03-8 dimethylglyoxal 
• 85526-22-3 3-Hydroperoxy-3-methoxy-2-methyl-1-butene 
• 129156-01-0 (1,2-dimethyl-1-propenyl)dimethylphenylsilane 
• 85526-18-7 3-Isopropenyl-3-methyl-1,2,4-trioxolan 
• 115-19-5 2-methyl-but-3-yn-2-ol 
• 64-19-7 acetic acid 
• 79-31-2 isobutyric Acid 
• 78-80-8 2-methylbut-1-en-3-yne 
• 50-00-0 formaldehyd 
• 78-93-3 butanone 
• 557-93-7 2-bromoprop-1-ene 

Downstream Products

• 22104-62-7 4-dimethylamino-3-methylbutan-2-one 
• 7474-10-4 3,4,6-trimethyl-2-cyclohexen-1-one 
• 44642-69-5 4-Methylamino-3-methylbutanon-2 
• 30359-59-2 3-chloro-3-methyl-4-(2,4,5-trichlorophenyl)butan-2-one 
• 87682-31-3 2-benzoyl-1,2,3,4,8,8a-hexahydro-7-methyl-6-isoquinolone 
• 21869-55-6 3-methyl-4-phenylbutan-2-one 
• 20120-26-7 (2-methyl-3-morpholin-4-yl)propionic acid methyl ester 
• 598-75-4 3-methyl-2-butanol 
• 563-80-4 3-methyl-butan-2-one 
• 5920-41-2 1-(2,4-dinitro-phenyl)-3,4-dimethyl-4,5-dihydro-1H-pyrazole 
• 851605-63-5 4-(1,5-dimethyl-4-hexenyl)-6-methyl-2-cyclohexen-1-one 
• 61599-05-1 4-methyl-4-acetyl-2-cyclohexen-1-one 
• 97400-46-9 4-acetyl-4-methyl-6-phenylselenocyclohex-2-enone 
• 42420-88-2 2-methyl-4,4-diphenylcyclohexanone 

Relevant articles and documents

Cassis and Green Tea: Spontaneous Release of Natural Aroma Compounds from β-Alkylthioalkanones

In depth headspace analysis of the slow degradation of β-alkylthioalkanones in ambient air led to the discovery of a novel δ-cleavage pathway, by which β-mercaptoketones are released. Since β-mercaptoketones are potent natural aroma compounds occurring in many fruits, herbs and flowers, the discovery of an enzyme-independent molecular precursor for this class of high-impact molecules is of practical importance. Moreover, the formation of β-diketones and aldehydes by concomitant oxidation at the α-sulfur-position enhances the versatility of this class of aroma precursors. A mechanistic model is proposed which suggests that the oxidative degradation occurs through a novel Pummerer-type rearrangement of initially formed persulfoxides.

Ketone Formation from Carboxylic Acids by Ketonic Decarboxylation: The Exceptional Case of the Tertiary Carboxylic Acids

For the reaction mechanism of the ketonic decarboxylation of two carboxylic acids, a β-keto acid is favored as key intermediate in many experimental and theoretical studies. Hydrogen atoms in the α-position are an indispensable requirement for the substrates to react by following this mechanism. However, isolated observations with tertiary carboxylic acids are not consistent with it and these are revisited and discussed herein. The experimental results obtained with pivalic acid indicate that the ketonic decarboxylation does not occur with this substrate. Instead, it is consumed in alternative reactions such as disintegration into isobutene, carbon monoxide, and water (retro-Koch reaction). In addition, the carboxylic acid is isomerized or loses carbon atoms, which converts the tertiary carboxylic acid into carboxylic acids bearing α-proton atoms. Hence, the latter are suitable to react through the β-keto acid pathway. A second substrate, 2,2,5,5-tetramethyladipic acid, reacted by following the same retro-Koch pathway. The primary product was the monocarboxylic acid 2,2,5-trimethyl-4-hexenoic acid (and its double bond isomer), which might be further transformed into a cyclic enone or a lactone. The ketonic decarboxylation product, 2,2,5,5-tetramethylcyclopentanone was observed in traces (0.2 % yield). Therefore, it can be concluded that the observed experimental results further support the proposed mechanism for the ketonic decarboxylation via the β-keto acid intermediate.

Hydroxyketones in the thiadiazine cycle formation

Cyclocondensation of 1-hydroxyketones with thiosemicarbazide resulted in thiadiazines. Nitrate ester of 1-hydroxyketone reacted under similar conditions to give the corresponding thiosemicarbazone. In the case of bromoacetyl-substituted nitrate ester of 1-hydroxyketone, condensation proceeded via intramolecular reaction between the thiol and bromomethyl groups.

A structure/catalytic activity study of gold(i)-NHC complexes, as well as their recyclability and reusability, in the hydration of alkynes in aqueous medium

We conducted a structure/catalytic activity study of water-soluble gold(i) complexes-supporting sulfonated NHC ligands-in the hydration of alkynes in pure water or water nsp;:nsp;methanol (1nsp;:nsp;1), as well as their recyclability. Comparative studies were carried out with the addition of different silver salts. Our results indicate that the bulkier complex is the most effective and that the addition of methanol as co-solvent not only shortens reaction times but also stabilizes the less bulky complexes.

3-methyl-3-penten-2-one preparation method

The invention relates to a preparation method of 3-methyl-3-amylene-2-ketone. The preparation method comprises the steps of mixing butanone and a solid acid catalyst at 0-80 DEG C, adding acetaldehyde, fully mixing, reacting continuously, separating and purifying after reaction to obtain the 3-methyl-3-amylene-2-ketone, wherein the solid acid catalyst is highly-acidic dry type sulfonic acid group based polystyrene with H or sulfonic acid group based perfluorination cation exchange resin. According to the method, the solid acid catalyst is adopted, compared with the traditional synthetic method that strong acid and strong base are used, the method can greatly reduce the follow-up separation difficulty and environment pollution degree, no equipment corrosion is caused, and the product yield and the purity are high, therefore, the preparation method of 3-methyl-3-amylene-2-ketone is green and environment-friendly; and besides, no assisted solvent is adopted, the follow-up separation difficulty is reduced, the energy consumption and the production cost are low, and the industrial reliability is strong.

A mild method for the replacement of a hydroxyl group by halogen. 1. Scope and chemoselectivity

α-Chloro-, bromo- and iodoenamines, which are readily prepared from the corresponding isobutyramides have been found to be excellent reagents for the transformation of a wide variety of alcohols or carboxylic acids into the corresponding halides. Yields are high and conditions are very mild thus allowing for the presence of sensitive functional groups. The reagents can be easily tuned allowing therefore the selective monohalogenation of polyhydroxylated molecules. The scope and chemoselectivity of the reactions have been studied and reaction mechanisms have been proposed.

Aluminum oxide-induced gas-phase ring-opening in methyl substituted gem-difluorocyclopropanes, leading to 2-fluorobuta-1,3-dienes and vinylacetylenes

A gas-phase pyrolysis of methyl-substituted gem-difluorocyclopropanes in a flow-tube reactor in the presence of Al2O3 at 185 - 250 °C gives 2-fluorobuta-1,3-dienes and vinylacetylenes.

Reactions of a tungsten-germylyne complex with α,β-unsaturated ketones: Complete cleavage of the W/Ge bond and formation of two types of η3-germoxyallyl tungsten complexes

Germylyne complex Cp(CO)2W/Ge{C(SiMe3)3} (1) reacted with two molecules of RC(O)CH=CH2 (R = Me, Et) to give η3-allyl complexes, in which an oxagermacyclopentene framework was bound to an η3-allyl ligand through an oxygen atom. In the reaction with α-Me-substituted MeC(O)C(Me)=CH2, 1 reacted with only one molecule of the substrate to give another type of η3- allyl complex, in which a five-membered oxagermacyclopentenyl ring was coordinated to the W center in an η3 fashion. Both reactions resulted in unprecedented complete cleavage of a W/Ge triple bond.

Silica-supported HgSO4/H2SO4: A convenient reagent for the hydration of alkynes under mild conditions

The silica-supported aqueous-phase catalyst (SAPC) approach has proven convenient for efficiently performing the hydration of alkynes with HgSO 4/H2SO4 to give the corresponding carbonyl compounds in dichloromethane under mild conditions. The use of this solid reagent significantly improves the reaction work-up as it merely involves filtering and evaporating the solvent.

Isolable gold(I) complexes having one low-coordinating ligand as catalysts for the selective hydration of substituted alkynes at room temperature without acidic promoters

Hydration of a wide range of alkynes to the corresponding ketones has been afforded in high yields at room temperature by using gold(I)-phosphine complexes as catalyst, with no acidic cocatalysts required. Suitable substrates covering alkyl and aryl terminal alkynes, enynes, internal alkynes, and propargylic alcohols, including enantiopure forms, are cleanly transformed to the corresponding ketones in nearly quantitative yields. Acid-labile groups present in the substrates are preserved. The catalytic activity strongly depends on both the nature of the phosphine coordinated to the gold (I) center and the softness of the counteranion, the complex AuSPhOsNTf2 showing the better activity. A plausible mechanism for the hydration of alkynes through ketal intermediates is proposed on the basis of kinetic studies. The described catalytic system should provide an efficient alternative to mercury-based methodologies and be useful in synthetic programs.