Methyl isobutyrate

The distikative separation of methacrylic acid from unreacted isobutyric acid is problematic because the boiling points of isobutyric acid (155°C) and methacrylic acid (162°C) are quite close to one another. Alternatively, the cmde reaction mixture can be esterified, and the resultant methyl methacrylate (101°C) and methyl isobutyrate (92°C) can be separated. 

Acetic anhydride B 31 Diethyl ether A 60 Methyl isobutyrate B... 

On reaction with Li-HMDS 492 and subsequent treatment with MegSiCl 14 a-ketoesters such as 512 afford N-silylated Schiff bases such as 513, which can be reduced to amino acids 514 or amino alcohols 515 and dimerized with methanol or H2O to give the imidazolone 516 [95]. Analogous treatment of benzil with Li-HMDS 492 and quenching with Me3SiCl 14 gives 517, which reacts with the Li-enolate of methyl isobutyrate 498 at 78 °C in THF to give the adduct 518 in 75%... 

In Section 5.1.3 the conversion of aldehydes 491 and 494 into N-silylated Schiff bases and their in-situ reaction with allylmagnesium bromide into unsaturated secondary amines 493 and 495 is described. Likewise, reactions of the N-silylated Schiff bases such as 489 with the lithium enolate of methyl isobutyrate 498 to give yS-lactams such as 499 are also discussed in Section 5.1.3. 

In turn, a lipase-promoted acylahon of prochiral substrates 104, using lipases from Candida cylinracea and Chromobacterium viscosum and methyl isobutyrate or acetoxime isobutyrate as the acyl donors, gave the product 105 in yields up to 80% and with ees up to 75% (Equahon 50). ... 

Isobutyl fomtafe Propyl acetate isopropyl acetate Ethyl propionate Methyl butyrate Methyl isobutyrate Diethyl carbohale Edtyl lactate 2-Methoxyethyl acetate... 

N-VALERIC ACID ISOBUTYL FORMATE N-PROPYL ACETATE ETHYL PROPIONATE METHYL BUTYRATE METHYL ISOBUTYRATE PIPERIDINE N-PENTANE 2-METHYL BUTANE 2 2-DIMETHYL PROPANE... 

The electron impact mass spectrum of methyl isobutyrate, 27, contains a signal for a [M—CH3]+ ion. 2H- and 13C-labelling clearly establishes that the eliminated methyl radical originates exclusively from the intact PCH3 group (6)12,13,1 . 

By 1989 Mukaiyama had already explored the behaviour of phosphonium salts as Lewis acid catalysts. It was possible to show that the aldol-type reaction of aldehydes or acetals with several nucleophiles and the Michael reaction of a,j3-unsatu-rated ketones or acetals with silyl nucleophiles gave the products in good yields with a phosphonium salt catalyst [116]. In addition, the same group applied bisphosphonium salts as shown in Scheme 45 in the synthesis of ]3-aminoesters [117]. High yields up to 98% were obtained in the reaction of A-benzylideneaniline and the ketene silyl acetal of methyl isobutyrate. Various analogues of the reaction parteers gave similar results. The bisphosphonium salt was found to be superior to Lewis acids like TiCl and SnCl, which are deactivated by the resulting amines. 

Other alkali/alkaline earth metal iodides either cleave esters less efficiently or form insoluble carboxylate salts and are therefore not as effective as Lil. Addition of Li and l" compounds capable of forming Lil under reaction conditions works as well as initially charging Lil (Table IV). The acetaldehyde producing step. Equation 17, is carried out with the cobalt-based catalyst. Since the carboxylate half of the ester is not involved with the cobalt center, any methyl ester which can be cleaved by Lil should also show activity. We have found that methyl isobutyrate, dimethyl malonate, methyl propionate, and dimethyl succinate yield acetaldehyde and the corresponding carboxylic acids in high yield under the same conditions utilized with methyl acetate. 

Methyl isobutyrate, Methyl(2-methyl-3-formyl)propionate, methyl (2-methyl-2-formyl) propionate... 

A considerable charge density at the carbonyl oxygen is also indicated by C-13 NMR measurements with the metalated "monomer (i.e. methyl isobutyrate) and dimer in THF, which were reported by Vancea and Bywater (35). They showed that the bond between the -carbon and the carbonyl carbon exhibits a distinct double bond character. 

Conductivity measurements of Mailer at al. (J ) on Cs(0.BCN) in THF and mixtures of THF with methyl isobutyrate (which serves as a model for the ester groups of the polymer) resulted lower dissociation constants in the mixture than in pure THF, as is to be expected from the lower dielectric constant of methyl isobutyrate. Thus, no specific solvation of Cs+ by the polymer ester groups could be shown, although a chelate-like effect could enhance the solvating power of the penultimate ester group of the active species. 

Farid and co-workers88 have investigated the effect of a glassy polymer host on the spectral position of the excimer emission peak produced by high concentrations of the compound methyl 4-(l-pyrenyl)-butyrate. The excimer peak position in a glassy polymer host was compared to the peak position in fluid solution for the following polymer hosts (and solvents) PS(toluene), PMMA(methyl isobutyrate), and poly-(vinyl benzoate) (methyl benzoate). The excimer emission peak of the pyrene compound in all three solvents occurred at about 20,800 cm-1, but the emission peak in all three polymer hosts was blue-shifted about 1900 cm-1 relative to the solution value. This is in contrast to the behavior of unsubstituted pyrene in PMMA 82) and PS 83), whose excimer peak does not shift from the solution value. 

Isobutyramide has been prepared by the action of concentrated aqueous ammonia on isobutyryl chloride 3 or methyl isobutyrate 4 by distillation of ammonium isobutyrate 5 or a mixture of isobutyric acid and potassium thiocyanate.6 Hydrolysis of isobutyronitrile also results in the formation of isobutyramide. 7... 

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