Acetone, mesityl oxide from

Formation of mesitylene from acetone corresponds to that of mesityl oxide from acetone. 

Fit a 750 ml. round-bottomed flask with a fractionating column attached to a condenser set for downward distillation. Place 500 g. of diacetone alcohol (the crude product is quite satisfactory), 01 g. of iodine and a few fragments of porous porcelain in the flask. Distil slowly. with a small free flame (best in an air bath) and collect the following fractions (a) 56-80° (acetone and a little mesityl oxide) (6) 80-126° (two layers, water and mesityl oxide) and (c) 126-131° (mesityl oxide). Whilst fraction (c) is distilling, separate the water from fraction (6), dry with anhydrous potassium carbonate or anhydrous magnesium sulphate, and fractionate from a small flask collect the mesityl oxide at 126-131°. The yield is about 400 g. 

The yield of acetone from the cumene/phenol process is beUeved to average 94%. By-products include significant amounts of a-methylstyrene [98-83-9] and acetophenone [98-86-2] as well as small amounts of hydroxyacetone [116-09-6] and mesityl oxide [141-79-7]. By-product yields vary with the producer. The a-methylstyrene may be hydrogenated to cumene for recycle or recovered for monomer use. Yields of phenol and acetone decline by 3.5—5.5% when the a-methylstyrene is not recycled (21). 

Although the selectivity of isopropyl alcohol to acetone via vapor-phase dehydrogenation is high, there are a number of by-products that must be removed from the acetone. The hot reactor effluent contains acetone, unconverted isopropyl alcohol, and hydrogen, and may also contain propylene, polypropylene, mesityl oxide, diisopropyl ether, acetaldehyde, propionaldehyde, and many other hydrocarbons and carbon oxides (25,28). 

Some unsaturated ketones derived from acetone can undergo base- or acid-catalyzed exothermic thermal decomposition at temperatures under 200°C. Experiments conducted under adiabatic conditions (2) indicate that mesityl oxide decomposes at 96°C in the presence of 5 wt % of aqueous sodium hydroxide (20%), and that phorone undergoes decomposition at 180°C in the presence of 1000 ppm iron. The decomposition products from these reactions are endothermic hydrolysis and cleavage back to acetone, and exothermic aldol reactions to heavy residues. 

Ma.nufa.cture. Mesityl oxide is produced by the Hquid-phase dehydration of diacetone alcohol ia the presence of acidic catalysts at 100—120°C and atmospheric pressure. As a precursor to MIBK, mesityl oxide is prepared ia this manner ia a distillation column ia which acetone is removed overhead and water-saturated mesityl oxide is produced from a side-draw. Suitable catalysts are phosphoric acid (177,178) and sulfuric acid (179,180). The kinetics of the reaction over phosphoric acid have been reported (181). 

Diacetunamine has been prepared in satisfactory yields by treating a mixture of commercial acetone and calcium chloride with anhydrous ammonia. The preparation from commercial acetone and ammonia is laborious and gives low yields. No yields are given in the older published descriptions of the preparation from mesityl oxide with either aqueous or anhydrous ammonia. The method described here has recently been published. ... 

Besides acetophenone, this reaction was also applied to p-chloro- andp-methoxyacetophenone, and even to an aliphatic ketone, acetone (although the yield was stated to be only half as large as that obtained from mesityl oxide, i.e., less than 30%, Dorofeenko and co-workers reported a 45% yield of 2,4,6-trimethylpyrylium perchlorate from acetone, acetic anhydride, and perchloric acid), and is the standard method for preparing pyrylium salts with identical substituents in positions 2 and 4. The acylating agent may be an anhydride in the presence of anhydrous or hydrated ferric chloride, or of boron fluoride, or the acid chloride with ferric chloride.Schneider and co-workers ... 

The well-known condensation between 2-furaldehyde and acetone in a basic medium yields what is usually called furfurylidene acetone monomer composed of a mixture of 2-furfurylidene methyl ketone, di-2-furfurylidene ketone, mesityl oxide and other oligomers derived from further condensation reactions135. This mixture is then polymerized by the action of an acidic catalyst in the first phase of the reaction a polymer of low molecular weight is produced which on further treatment cross-links to a black insoluble and heat-resistant material136. ... 

Purely parallel reactions are e.g. competitive reactions which are frequently carried out purposefully, with the aim of estimating relative reactivities of reactants these will be discussed elsewhere (Section IV.E). Several kinetic studies have been made of noncompetitive parallel reactions. The examples may be parallel formation of benzene and methylcyclo-pentane by simultaneous dehydrogenation and isomerization of cyclohexane on rhenium-paladium or on platinum catalysts on suitable supports (88, 89), parallel formation of mesityl oxide, acetone, and phorone from diacetone alcohol on an acidic ion exchanger (41), disproportionation of amines on alumina, accompanied by olefin-forming elimination (20), dehydrogenation of butane coupled with hydrogenation of ethylene or propylene on a chromia-alumina catalyst (24), or parallel formation of ethyl-, methylethyl-, and vinylethylbenzene from diethylbenzene on faujasite (89a). 

It is often said that the property of acidity is manifest only in the presence of a base, and NMR studies of probe molecules became common following studies of amines by Ellis [4] and Maciel [5, 6] and phosphines by Lunsford [7] in the early to mid 80s. More recently, the maturation of variable temperature MAS NMR has permitted the study of reactive probe molecules which are revealing not only in themselves but also in the intermediates and products that they form on the solid acid. We carried out detailed studies of aldol reactions in zeolites beginning with the early 1993 report of the synthesis of crotonaldehyde from acetaldehyde in HZSM-5 [8] and continuing through investigations of acetone, cyclopentanone [9] and propanal [10], The formation of mesityl oxide 1, from dimerization and dehydration of... 

A Catalytic Distillation Process for the One Step Synthesis of Methyl Isobutyl Ketone from Acetone Liquid Phase Kinetics of the Hydrogenation of Mesityl Oxide... 

The present economic and environmental incentives for the development of a viable one-step process for MIBK production provide an excellent opportunity for the application of catalytic distillation (CD) technology. Here, the use of CD technology for the synthesis of MIBK from acetone is described and recent progress on this process development is reported. Specifically, the results of a study on the liquid phase kinetics of the liquid phase hydrogenation of mesityl oxide (MO) in acetone are presented. Our preliminary spectroscopic results suggest that MO exists as a diadsorbed species with both the carbonyl and olefin groups coordinated to the catalyst. An empirical kinetic model was developed which will be incorporated into our three-phase non-equilibrium rate-based model for the simulation of yield and selectivity for the one step synthesis of MIBK via CD. 

The liquid phase kinetics of the selective hydrogenation of mesityl oxide in acetone were studied for the purpose of developing a robust kinetic model to be integrated into an existing non-equilibrium rate-based model for the simulation of the CD process for MIBK production. A typical concentration versus time profde is illustrated in Figure 2. MIBK was produced with veiy high selectivity with essentially all of the MO converted to MIBK. Products from the... 

The reaction mechanism is shown in Figure 4 and is adapted from work by Fiego et al. [9] on the acid catalysed condensation of acetone by basic molecular sieves. The scheme has been modified to include the hydrogenation of mesityl oxide to MIBK. The scheme begins with the self-condensation of acetone to form diacetone alcohol as the primary product. The dehydration of DAA forms mesityl oxide, which undergoes addition of an addition acetone to form phorone that then can cyclise, via a 1,6-Michael addition to produce isophorone. Alternatively, the mesityl oxide can hydrogenate to form MIBK. 

Trimethylpyrylium perchlorate has been prepared from 2,6-dimethylpyrone and methylmagnesium halides 6 from mesityl oxide and sulfoacetic acid 6 from mesityl oxide (or less satisfactorily from acetone) and a mixture of acetic anhydride and perchloric acid 7 from mesityl oxide, acetyl chloride, and aluminum chloride 8 and from <-butyl chloride, acetyl chloride,... 

Mesitylene, production from acetone, 1 164 Mesityl oxide, 14 589-590 characteristics of, 16 337 hydrogenation, 16 337-338 hydrogen peroxide treatment of, 16 338 Z-menthol from, 24 520 production of, 16 336-337 production from acetone, 1 164, 174 Mesogenic diols, 25 460 Mesogenic molecules, solids of, 15 82 Mesogens, 24 53, 54 Mesomixing, 16 683 Mesomorphic behavior, 24 53-54 Mesomorphic phase transitions, 15 102 Mesomorphism, 15 81. See also Liquid crystalline materials Mesophase pitch-based carbon fiber, 26 734-735... 

The pilot scale experiments were carried out in a CD column 23 ft (7 m) tall with a total packing height of 16 ft (4.9 m) and a 1 (2.54 cm) nominal I.D. The column is made of 316 SS and consists of 5 sections that are connected by flanges. Two 2 ft (0.6 m) sections located above a 9 ft (2.7 m) stripping section and below a 3 ft (0.9 m) rectification section, were used as the reaction zones, which contained the catalyst. The non-reactive sections were filled with i inch (0.64 cm) Intalox saddles. In the first experiment for which mesityl oxide was synthesized from acetone, the two sections were filled with 130 mL of Amberlyst-15, that had been swelled in 2-propanol for 24 hours, in wire mesh bundles. In the second experiment in which MIBK was synthesized from acetone, the top section and the top half of the bottom section contained 135.0 mL of Amberlyst-15 in wire mesh bundles that had been swelled in acetone for over 24 hours. The bottom half of the bottom section, immediately below the Amberlyst 15, was filled with 50.1 g of a commercial Pd/AlzOs catalyst (Aldrich 20,574-5). The hydrogenation catalyst was reduced ex situ in hydrogen at 350°C for 3 hours and was transferred to the CD column under a nitrogen blanket. 

In the first experiment, Amberlyst-15, a strongly acidic cation exchange resin, was used as a catalyst to synthesize mesityl oxide, the precursor of MIBK, from acetone without hydrogenation. The effects of acetone feed rate, reboiler duty and reaction temperature on the mesityl oxide productivity and product distribution were investigated. Preliminary results of this experiment are outlined in Table 1. 

It was found that the mesityl oxide productivity was a strong function of the reflux flow rate in the CD column, which suggests the reaction is controlled by the rate of external mass transfer. It is also evident from Table I that acetone conversions as high as essentially 100% can be achieved with the mesityl oxide concentration in the... 

Occasionally pyrans result from an aldolization process. Thus 2,2,4,6-tetramethyl-2//-pyran (124) is a byproduct in the production of mesityl oxide and diacetone alcohol from acetone.189,190 Ketol 146 (readily accessible from... 

Fig. 7. Energy-minimized structures of acetone and mesityl oxide adsorption complexes on a cluster model of HZSM-5 using DFT calculation. Note that in the case of the acetone complex, the proton remains bonded to the bridging oxygen, while in the case of the mesityl oxide complex, the proton is more fully transferred to the ketone. (Reprinted with permission from Haw et al. (7). Copyright 1996 American Chemical Society.)...

The crude diacetone alcohol is prepared according to the directions in Exp. IX (p. 45). The acetone recovered from the preparation of mesityl oxide can be mixed with fresh acetone and successfully used in preparing more crude diacetone alcohol. 

The methods of making mesityl oxide fall into three classes (1) the action of condensing agents (hydrochloric acid, etc.) on acetone 1 (2) the dehydration of diacetone alcohol 2 (3) and from diacetonamine.3 The latter method was not considered since the amine is relatively difficult to prepare. The action of acid condensing agents on acetone is very unsatisfactory the yields are poor and considerable quantities of phorone and similar substances are invariably produced. The direct production... 

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