Methyl isopropenyl ketone, reaction

Other uses include use as a reaction and extraction solvent in pharmaceutical production as an intermediate for the preparation of catalysts, antioxidants (qv), and perfumes and as a feedstock in the production of methyl isopropenyl ketone, 2,3-butanedione, and methyl ethyl ketone peroxide. Concern has also arisen at the large volume of exported MEK which has been covertly diverted and used to process cocaine in Latin American countries... 

At higher temperatures the mixture of 10 and methyl vinyl ketone yields the 1,4-carbocyclic compound as described previously. Methyl isopropenyl ketone (5), ethyl acetylacrylate (d), 2-cyclohexenone (21), and 1-acetyl-1-cyclohexene (22) also undergo this type of cyclization reaction with enamines at higher temperatures. This cycloalkylation reaction occurs with enamines made of strongly basic amines such as pyrrolidine, but the less reactive morpholine enamine combines with methyl vinyl ketone to give only a simple alkylated product (7). Chlorovinyl ketones yield pyrans when allowed to react with the enamines of either alicyclic ketones or aldehydes (23). 

The efficiency of the type I reaction usually depends on the relative stability of the radicals produced. For this reason, higher type I quantum efficiencies would be expected for methyl isopropenyl ketone (MIPK) styrene copolymers because the polymer chain radical formed is tertiary rather than secondary, i.e.,... 

The methylene group of methyl ethyl ketone is active in the condensation to give, upon pyrolysis, only methyl isopropenyl ketone (92%). Olefinic aldehydes, acids, esters, and nitro compounds have been prepared in a similar manner. The literature of the Mannich reaction has been reviewed. ... 

Preparation of Monomers. Methyl vinyl ketone (MVK) was obtained from Pfizer Chemical Division, New York, and distilled to remove the inhibitor. Methyl isopropenyl ketone (MIPK) was prepared by the aldol condensation of methyl ethyl ketone and formaldehyde, according to the method of Landau and Irany 0. The major impurity in this monomer is ethyl vinyl ketone (5. The monomer was redistilled before use. 3 Ethyl 3 buten 2 one (EB) was prepared by the aldol condensation of methyl propyl ketone and formaldehyde. Ethyl vinyl ketone (EVK) was prepared by a Grignard synthesis of the alcohol, followed by oxidation to the ketone. t-Butyl vinyl ketone (tBVK) was prepared from pinacolone and formaldehyde by the method of Cologne (9). Phenyl vinyl ketone (PVK) was prepared fay the dehydrochlorlnatlon of 0 cbloro propiophenone (Eastman Kodak). Phenyl isopropenyl ketone (PPK) was prepared by the Mannich reaction using propiophenone, formaldehyde and dimethylamine HCl. 

METHYL-3-BUTEN-2-ONE (German) (814-78-8) see methyl isopropenyl ketone. 1-METHYLBUTYL ACETATE (626-38-0) C7H14O, CH3COOCH(CH3)C3Ht Forms explosive mixture with air [explosion limits in air (vol %) 1.0 to 7.5 flash point 89°F/32°C autoignition temp 716°F/380°C Fire Rating 3]. Violent exothermic reaction... 

METHYL ISOPROPENYL KETONE (814-78-8) Forms explosive mixture with air (flash point 68°F/20°C). Violent reaction with aldehydes, nitric acid, perchloric acid, strong oxidizers. Contact with hydrogen peroxide can form unstable peroxides heat and/or inappropriate level of inhibitor may cause polymerization. 

Selective reduction of the carbonyl group of a,/S-unsaturated aldehydes and ketones has been achieved by a vapor-phase hydrogen transfer reaction using saturated primary and secondary alcohols as hydrogen donors. The preferred catalyst for the reaction, which is reversible, is magnesium oxide. Application to the reduction of acrolein to allyl alcohol, methacrolein to methallyl alcohol, crotonaldehyde to crotyl alcohol, and methyl isopropenyl ketone to 3-methyl-3-buten-2-ol is described. 

The use of ethyl alcohol for the selective reduction of the carbonyl group in unsaturated aldehydes and ketones other than acrolein is illustrated in Table V. Here also, the data listed are the best obtained in a limited number of runs with each compound and do not necessarily represent optimum conditions. As previously stated, in the acrolein-allyl alcohol reaction a small amount of propyl alcohol is found in the products. This side reaction appears to be considerably more important with crotonaldehyde, since the C4 alcohol fraction here contained 27 % butyl alcohol. The relatively high conversion to saturated alcohol is believed to be due in part to unfavorable reaction conditions. With methacrolein and with methyl isopropenyl ketone the saturated alcohol amounted to 5 % of the imsaturated alcohol produced. 

The dark initiation of the photosensitized degradation of a styrene-methyl isopropenyl ketone copolymer by thermally generated 7i(3iwr ) acetone using the tetramethyl-l,2-dioxetan dissociation reaction has been studied.217 The reaction... 

The procedure involves reaction in acetic anhydride, or in another solvent, followed by the addition of acetic anhydride to decompose the intermediate complex. The procedure has been extensively examined in relation to the 5-methyl- and 4,5-dimethyl-substituted compounds derived from ethenyl methyl and methyl isopropenyl ketones and with mesityl oxide which gives the 3,3,5-trimethyl-substituted compounds. Amongest the phosphorus reactants, the trichloride itself and methyl- " , ethyl- " " and phenyl- phosphonous dichlorides have been employed, as have ethyl and phenyP dichlorophosphites, ROPCI2. The use of 2-thienylphosphonous dichloride to give 137 is recorded as is that of the unsaturated ketone 138 to give 139. A more novel conversion is that of 140 into 141 in 25% yield with a similar conversion (15%) being observed for cholest-4-en-3-one. ... 

In the case of the borosilicate zeolite, the selectivity is lowered due to the formation of dimeric methyl isopropenyl ketone. The activity of the borosilicate zeolite can be increased and the side reaction... 

Chaudhuri [347] reported a thermally initiated polymerization of methyl isopropenyl ketone in bulk and solution. The reaction order with respect to monomer was less than 2 in homogeneous and greater than 2 in heterogeneous systems. Chain transfer [348] increased in the order benzene < toluene < ethylbenzene as solvents. 

Lyons and Catterall reported on the mechanism of n-butyl lithium-initiated polymerization of methyl isopropenyl ketone in benzene at 0°C [352,358]. Relatively rapid initial consumption of monomer gave rise to a bimodal molecular weight distribution of low which was maintained throughout the entire reaction. 

Conjugate addition was almost quantitative for the reaction between di- -butyl zinc or tri-n-butyl aluminum and both methyl isopropenyl ketone and phenyl vinyl ketone. With 2-furyl vinyl ketone an increase in initiator concentration produced crosslinking of the material [353]. 

The low chemical and thermal stability of poly(vinyl ketones) leads to a sensitivity to degradation reactions. Poly(methyl isopropenyl ketone) lost water at about 250 °C, to yield glassy, red, non-crosslinked products. It was proposed that an intramolecular aldol... 

Methyl-6-hydroxymethyl-pyrone-2 methacrylate, MA copolymerization, 284 Methyl isobutyl ketone MA telomer, 660 permaleic acid oxidation, 77 Methyl isooleate, MA ene reaction, 162, 163 Methyl isopropenyl ether, 316 Methyl isopropenyl ketone, MA copolymerization, 322... 

The chemically induced dynamic nuclear polarization (CIDNP) phenomenon, (the occurrence of intense emission and enhanced absorption lines in high-resolution NMR spectra during chemical reactions) has been applied to the study of the photodegradation of poly(methyl isopropenyl ketone) [177]. 

A macromolecular chain presents a unique reaction situation in which, in certain cases, groups which are potential reactants at elevated temperature are located in close proximity. Thus intramolecular cyclization may occur, which may or may not involve elimination of small molecules. For example, vinyl ketone polymers such as poly(methyl vinyl ketone) (PMVK), poly(methyl isopropenyl ketone) (PMIK) and poly(phenyl vinyl ketone) undergo random cyclization of adjacent monomer units with release of water. The reaction for PMVK is illustrated in Scheme 4. 

On distillation with a small proportion of iodine, oxalic acid, sulfuric acid, or other acidic catalysts., monomethylol methyl ethyl ketone is readily dehydrated to methyl isopropenyl ketone (b.p. 98 °C) which yields li -colored resins on poh merization and other resins by chemical reaction . ... 

However, the structural survey of the low molecular weight products by Kawabata and Tsuruta58 seems to indicate that carbonyl addition was not a predominant side-reaction since the amount of butyl isopropenyl ketone (BIPK) formed was very small, particularly in the polymerization in toluene. The problem was solved almost completely by totally deuterated monomer technique.59-63 The poly(MMA-rf8) prepared with n-C4H9Li in toluene showed in lH NMR signals due to the methyl (0.79 ppm) and methylene... 

Some abnormalities were reported in the initiations of methyl methacrylate polymerizations in toluene by butyllithium. Their nature is such that they suggest the possibility of more than one reaction taking place simultaneously. One, which must be the major one, is that of the oiganomet-allic compound reacting with the carbon-to-carbon double bond as shown above. The other, minor one, may be with the carbon-to-oxygen double bond. The major reaction produces methyl methacrylate anions. The minor reaction, however, yields butyl isopropenyl ketone with an accompanying formation of lithium methoxide ... 

Using an enzymatic diastereosdective acetylation process, the (5R,3J )-alcohol 54a was prepared from racemic 54 [107]. Lipase PS-30 effidendy catalyzed the acetylation of racemic 54 (4 g/L) to yield the (5i ,3S)-acetate 55 and the unreacted, desired (5P,31 )-alcohol 54a. A reaction yield of 49 M% and an ee of 98.5% was obtained for (5P,31 )-alcohol 54a when the reaction was conducted in toluene in the presence of isopropenyl acetate as an acyl donor. In methyl ethyl ketone at 50 g/L substrate concentration, a reaction yield of 46 M% and ee of 96% were obtained for (51 ,31 )-alcohol 54a [107]. 

With aldehydes, primary alcohols readily form acetals, RCH(OR )2. Acetone also forms acetals (often called ketals), (CH2)2C(OR)2, in an exothermic reaction, but the equiUbrium concentration is small at ambient temperature. However, the methyl acetal of acetone, 2,2-dimethoxypropane [77-76-9] was once made commercially by reaction with methanol at low temperature for use as a gasoline additive (5). Isopropenyl methyl ether [116-11-OJ, useful as a hydroxyl blocking agent in urethane and epoxy polymer chemistry (6), is obtained in good yield by thermal pyrolysis of 2,2-dimethoxypropane. With other primary, secondary, and tertiary alcohols, the equiUbrium is progressively less favorable to the formation of ketals, in that order. However, acetals of acetone with other primary and secondary alcohols, and of other ketones, can be made from 2,2-dimethoxypropane by transacetalation procedures (7,8). Because they hydroly2e extensively, ketals of primary and especially secondary alcohols are effective water scavengers. 

Japanese workers (50,51) were the first to observe optical activity in the addition of thiols to electron-poor olefins (eq. [9]) The e.e. was not determined, but these observations led us to attempt using a cinchona alkaloid as the catalyst in the addition of thiophenol to cyclohexenone. The reaction lends itself admirably to a scope, limitations, and mechanism study, and the results have been published in detail (19). An important mechanistic difference between the addition of the dodecanethiol to isopropenyl methyl ketone and the addition of thiophenol to a cyclohexenone (eq. [1]) lies in the sequence of chirality-producing steps. In the former case, chirality is produced when the proton adds to the a-caibon atom of the ketone—after thiol addition has taken place. In the latter... 

Several different nucleophilic substitution reactions have been observed in the polymerization of methyl methacrylate. Attack of initiator on monomer converts the active alkyl-lithium to the less active alkoxide initiator (Eq. 5-75). Further, methyl methacrylate (MMA) is converted to isopropenyl alkyl ketone to the extent that this reaction occurs. 

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