Butyraldehydes

The two isomeric butanals, n- and isobutyraldehyde, C HgO, are produced commercially abnost exclusively by the Oxo Reaction of propylene. They also occur naturally ia trace amounts ia tea leaves, certain oils, coffee aroma, and tobacco smoke. 

The butanals are highly flammable, colorless Hquids of pungent odor. Their physical properties are shown ia Table 1. 

These aldehydes are miscible with most organic solvents, eg, acetone, ether, ethanol, and toluene, but are only slightly soluble ia water. Some a2eotropes of -butyraldehyde are given ia Table 2. 

The upper layer (94 vol %) contains 3.5 wt % water. The lower layer (6 vol %) contains 91.8% water. The upper layer (97.8 vol %) contains 11 wt % ethanol and 7 wt % water. 

Kirk-Othmer Encyclopedia of Chemical Technology (4th Edition) 

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Propionaldehyde. Use 34 g. (42-6 ml.) of n propyl alcohol, and a solution containing 56 g. of sodium chromate dihydrate, 300 ml. of water and 40 ml. of concentrated sulphuric acid. The experimental details are identical with those for n-butyraldehyde, except that the addition of the dichromate solution occupies 20 minutes, the temperature at the top of the column is not allowed to rise above 70-75°, and during the subsequent heating for 15 minutes the liquid passing over below 80° is collected the receiver must be cooled in ice. The yield of propionaldehyde, b.p. 47-50°, is 12 g. 

Aldehydes and ketones. re-Butyraldehyde Acetone Methyl re-amyl... 

Rhodium Ca.ta.lysts. Rhodium carbonyl catalysts for olefin hydroformylation are more active than cobalt carbonyls and can be appHed at lower temperatures and pressures (14). Rhodium hydrocarbonyl [75506-18-2] HRh(CO)4, results in lower -butyraldehyde [123-72-8] to isobutyraldehyde [78-84-2] ratios from propylene [115-07-17, C H, than does cobalt hydrocarbonyl, ie, 50/50 vs 80/20. Ligand-modified rhodium catalysts, HRh(CO)2L2 or HRh(CO)L2, afford /iso-ratios as high as 92/8 the ligand is generally a tertiary phosphine. The rhodium catalyst process was developed joindy by Union Carbide Chemicals, Johnson-Matthey, and Davy Powergas and has been Hcensed to several companies. It is particulady suited to propylene conversion to -butyraldehyde for 2-ethylhexanol production in that by-product isobutyraldehyde is minimized. 

The important solvent and plasticizer intermediate, 2-ethylhexanol, is manufactured from -butyraldehyde by aldol addition in an alkaline medium at 80-130°C and 300-1010 kPa (3-10 atm). 

The -butyraldehyde may be obtained from acetaldehyde [75-07-0] by aldol addition followed by hydrogenation, or from propylene by the 0x0 process. This latter process is predominantly favored (Eig. 7). 

The common method of naming aldehydes corresponds very closely to that of the related acids (see Carboxylic acids), in that the term aldehyde is added to the base name of the acid. For example, formaldehyde (qv) comes from formic acid, acetaldehyde (qv) from acetic acid, and butyraldehyde (qv) from butyric acid. If the compound contains more than two aldehyde groups, or is cycHc, the name is formed using carbaldehyde to indicate the functionaUty. The lUPAC system of aldehyde nomenclature drops the final e from the name of the parent acycHc hydrocarbon and adds al If two aldehyde functional groups are present, the suffix -dialis used. The prefix formjlis used with polyfunctional compounds. Examples of nomenclature types are shown in Table 1. 

Hydroformylation of an olefin usiag synthesis gas, the 0x0 process (qv), was first commercialized ia Germany ia 1938 to produce propionaldehyde from ethylene and butyraldehydes from propylene (12). 

Aristech Chemical Corp. United States and Canada butyraldehyde... 

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