Solid ketones

Fig. 121 —Phase diagram for three polyiso- shown by the dashed curves, butylene fractions (molecular weights indi- At temperatures not much cated) in diisobutyl ketone. Solid curves are below the critical tempera-drawn through the experimental points. The, m x...

Chin, K. F., and S. H. Sn. 2013. Lithiated and snlphonated polyfether ether ketone) solid state electrolyte films for snpercapacitors. Thin Solid Films 544 144—147. 

Sodium tetrahydridoborate Sec. alcohols from ketones Solid-state reduction... 

Oxidations. Copper sulfate is a mild reagent for the oxidation of reactive secondary alcohols to ketones. Solid mixture... 

Figure 4.3 Dependence of the critical temperature on the number of segments per polymer chain. Polystyrene in cylcohexane, open circles polyisobutene in diisobutyl ketone, solid circles (7).

Fig. 9.53 Plot of In G against crystallization temperature, T, for poly(aryl ether ether ketone). Solid curve according to Eq. (9.209) with U = 3690, C = 73, experimental results. (From Medellin-Rodriguez, et al. (198))...

A white solid, m.p. 178 C. Primarily of interest as a brominaling agent which will replace activated hydrogen atoms in benzylic or allylic positions, and also those on a carbon atom a to a carbonyl group. Activating influences can produce nuclear substitution in a benzene ring and certain heterocyclic compounds also used in the oxidation of secondary alcohols to ketones. 

The properties of the solids most commonly encountered are tabulated. An important problem arises for petroleum fractions because data for the freezing point and enthalpy of fusion are very scarce. The MEK (methyl ethyl ketone) process utilizes the solvent s property that increases the partial fugacity of the paraffins in the liquid phase and thus favors their crystallization. The calculations for crystallization are sensitive and it is usually necessary to revert to experimental measurement. 

An alternative method of working up the distillate, which has its advantages when dealing with volatile ketones or when it is suspected that conversion into the ketone is incomplete, is to treat the combined ketones with sodium hydroxide pellets until the mixture is alkaline. Should solids separate, these may be dissolved by the addition of a little water. The ketone is then separated, dried over anhydrous potassium carbonate, and fractionated. 

For water insoluble aldehydes or ketones, the following alternative procedure may be used. Reflux a mixture of 0-6 g. of the aldehyde or ketone, 0 5 g. of hydroxylamine hydrochloride, 5 ml. of ethanol and 0 5 ml. of pyridine on a water bath for 15-60 minutes. Remove the alcohol either by distillation (water bath) or by evaporation of the hot solution in a stream of air (water pump). Add 5 ml. of water to the cooled residue, cool in an ice bath and stir until the oxime crystallises Filter off the solid, wash it with a little water and dry. Recrystallise from alcohol (95 per cent, or more dilute), benzene, or benzene - light petroleum (b.p. 60-80°). 

Oximes (compare Section III,74,B). The following procedure has wide application. Dissolve 0-5 g. of hydroxylamine hydrochloride in 2 ml. of water, add 2 ml. of 10 per cent, sodium hydroxide solution and 0-2 g. of the aldehyde (or ketone). If the latter is insoluble, add just sufficient alcohol to the mixture to give a clear solution. Heat the mixture under reflux for 10-15 minutes, and then cool in ice. If crystals separate, filter these off, and recrystallise from alcohol, dilute alcohol, benzene or light petroleum (b.p. 60-80°). If no solid separates on cooling, dilute with 2-3 volumes of water, filter the precipitated sohd, and recrystallise. 

Alternatively, dissolve approximately equivalent amounts of the aldehyde (or ketone) and the solid reagent in the minimum volume of cold glacial acetic acid, and reflux for 15 minutes. The p-nitrophenyl-hydrazone separates on cooling or upon careful dilution with water. 

Aromatic ketones usually have relatively high boiling points, but distil with little or no decomposition. Many are solids. The vapours generally burn with a smoky flame. They react with the 2 4-dinitrophenyll hydrazine reagent (Section 111,74,/) or with the phenylhydrazine reagent... 

The commercial product, m.p. 53-55°, may be used. Alternatively the methyl -naphthyl ketone may be prepared from naphthalene as described in Section IV,136. The Friedel - Crafts reaction in nitrobenzene solution yields about 90 per cent, of the p-ketone and 10 per cent, of the a-ketone in carbon disulphide solution at — 15°, the proportions ore 65 per cent, of the a- and 35 per cent, of the p-isomer. With chlorobenzene ns the reaction medium, a high proportion of the a-ketone is also formed. Separation of the liquid a-isomer from the solid p-isomer in Such mixtures (which remain liquid at the ordinary temp>erature) is readily effected through the picrates the picrate of the liquid a-aceto compound is less soluble and the higher melting. 

It is better not to remove the lower bromoform layer in a separatory funnel, but to do so entirely by steam distillation complete oxidation of the ketone id thus ensured. The weight of recovered bromoform may be somewhat smaller (100-105 g.), but the yield of pure acid is increased to 36 g. The steam distillation must be carefully watched as a solid (carbon tetrabromide) may crystallise in the condenser this can easily be removed by turning ofi the water supply when the solid will soon melt and pass on into the distillate. 

The solid appears to be a mixture of the complexes CH,COOH.BF, and 2CH COOH.BF,. The latter appears to be a liquid and is alone soluble in ethylene dichloride the former is a solid. The solid moiioocetic acid complex is obtained by saturating an ethylene dichloride solution of acetic acid with boron trifluoride, filtering and washing the precipitate with the solvent it is hygroscopic and should be protected from moisture. It may be used as required 0-75 mol is employed with 0-26 mol of ketone and 0 6 mol of anhydride. 

Oximes, hydrazines and semicarbazones. The hydrolysis products of these compounds, t.e., aldehydes and ketones, may be sensitive to alkali (this is particularly so for aldehydes) it is best, therefore, to conduct the hydrolysis with strong mineral acid. After hydrolysis the aldehyde or ketone may be isolated by distillation with steam, extraction with ether or, if a solid, by filtration, and then identified. The acid solution may be examined for hydroxylamine or hydrazine or semicarbazide substituted hydrazines of the aromatic series are precipitated as oils or solids upon the addition of alkali. 

Ketones C=0 All values given below are lowered in liquid-film or solid-state spectra by about 10-20 cm Vapor-phase spectra have values raised about 20 cm Saturated 1725-1705 ... 

Methylarsine, trifluoromethylarsine, and bis(trifluoromethyl)arsine [371-74-4] C2HAsF, are gases at room temperature all other primary and secondary arsines are liquids or solids. These compounds are extremely sensitive to oxygen, and ia some cases are spontaneously inflammable ia air (45). They readily undergo addition reactions with alkenes (51), alkynes (52), aldehydes (qv) (53), ketones (qv) (54), isocyanates (55), and a2o compounds (56). They also react with diborane (43) and a variety of other Lewis acids. Alkyl haUdes react with primary and secondary arsiaes to yield quaternary arsenic compounds (57). 

Condensations of aldehydes and ketones are catalyzed homogeneously by acids and bases, but solid bases are preferred, such as anion exchange resins and alkah or alkaline earth hydroxides or phosphates. 

Potassium carbonate. Solid potassium hydroxide is very rapid and efficient. Its use is limited almost entirely to the initial drying of organic bases. Alternatively, sometimes the base is shaken first with a concentrated solution of potassium hydroxide to remove most of the water present. Unsuitable for acids, aldehydes, ketones, phenols, thiols, amides and esters. Also used for drying gaseous amines and ammonia. 

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