Spectroscopy 2- butanone

Chloroacetone, phenacylbromide, a-bromoisobutyrophenone, 3-bromo-3-methyl-2-butanone, 1 -alkylsulfonyl-3-bromo-2-propanone, and ethyl-y-chloroacetoacetate give with ammonium dithiocarbamate the corresponding 4-hydroxythiazolidine-2-thiones (177), which have a characteristic absorption between 273 and 279 nm. Dehydration by heating with dilute HCl can be followed by ultraviolet spectroscopy because the products formed (175) absorb at 315 to 340 nm. 

Enamines of several methyl ketones have been prepared and their isomer content estimated by NMR spectroscopy (13,39,43). The reaction of Ti[N(CH3)2l4 as the amine source and 3-methyl-2-butanone gave only 26 (Ri = Rj = CH3), which could be isomerized by prolonged heating to a 1 1 mixture ofthatenamine and enamine 27 (R, = Rj = CH3)(39). The reaction of morpholine and 3-methyl-2-butanone in benzene with a trace of acetic... 

Figure 6. Mole percent methyl methacrylate incorporated in poly(methyl)meth-acrylate-co-3-oximino-2-butanone methacrylate) copolymers as a function of monomer feed composition determined by Raman spectroscopy. Key -----------ideality...

NH3)5(V-0 = CR2)]2+ (67, 120, 168, 169, 177, 181). The complexes prepared in these ways include acetaldehyde, acetone, 2-butanone, cy-clopentanone, cyclobutanone, 2-cyclohexen-l-one, 2,2-dimethylpro-piophenone, and benzophenone. These complexes have been characterized by CV and IR spectroscopy. 

One of the most startling developments in nmr spectroscopy since its inception has been the discovery of chemically induced dynamic nuclear polarization or CIDNP. An especially dramatic example is provided by irradiation of 3,3-dimethyl-2-butanone with ultraviolet light. 

In this paper the origins of the difference in stability of catalysts on different support materials are discussed. Catalysts supported on y-alumina and on titania (anatase) have been tested in the oxidation of 1-butene to butanone. Fresh and spent catalysts have been investigated by means of temperature programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) to reveal the causes for deactivation. 

From a comparison of the spectroscopy of cyclo-butanone to that of cyclopentanone, we see apparently similar absorption and emission predissociative behavior for cyclobutanone when Xex > 313 nm, while no such effect is found for cyclopentanone. If we suggest that three competing pathways account for the predissociative behavior, we have done little more than to offer a detailed but uninformative representation of the observations. Furthermore, we would be forced into adding more primary acts when interpreting the [1,3]-shifts and aldehydeforming reactions discussed above. 

Hydride Transfer Reactions of Metal Formyl Complexes. We have found that metal formyl complexes can act as hydride donors to electrophiles such as ketones, alkyl halides, and metal carbonyls. EUNHrans-[ (CeHsO) 3P] (CO) 3FeCHO" reacts with 2-butanone overnight at ambient temperature to give a 95% yield of 2-butanol. The possibility that 2-butanone is reduced by (CO)4FeH formed in situ from decomposition of the metal formyl complex is excluded since the metal formyl complex reacts with 2-butanone much faster than it decomposes to (CO)4FeH and since no reaction between (CO)4FeH and 2-butanone was observed by IR spectroscopy. 

A mixture of 25.0 g l-(3-nitrophenyl)-l-butanone (129 mmol), 77 mL formamide, and 35 mL formic acid was refluxed until the reaction was complete (followed by H NMR spectroscopy). After cooling to ambient temperature, 200 mL water was added, and the mixture was extracted with Et20 (3 x 100 mL). The combined organic layers were washed with brine, dried over Na2S04, and concentrated to furnish 28.7 g ( )-1-butyl-1-(3-nitrophenyl)formamide as a red oil, in a yield of 99%. 

Once the fundamentals of proton NMR spectroscopy are known, the next step is to use this information to predict what the NMR spectrum should look like for a given structure. It is difficrdt to translate chemical shift, integration, and multiplicity for an unknown spectrum into a structure if there is no notion of what the spectrum for a real molecule should look like. Therefore, in order to predict the proton NMR spectrum, a few examples are presented of known structures, beginning with 2-butanone. 

Recently, Li NMR spectroscopy has been used to establish that, in many cases, these oligomers do remain intact in solution. Thus, the enolate of cyclohexanone is dimeric in solution when TMEDA, Me2NCH2CH2NMe2, is added, but is a cubic tetramer in THE solutions. The predominance of dimers in TMEDA seems to be fairly general, including the enolates of cyclopentanone, cycloheptanone, 3,3,-dimethyl-2-butanone, acetophenone, and 2,5- dimethylp entanone. 

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