Butyraldehydes, from

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). 

Experiments designed to clarify the situation were carried out by Wittig and Mayer (40). It was shown that changing the molar ratio of amine (diethylamine, di- -butylamine, or diisobutylamine) to -butyraldehyde from 1 1 to 2 1 did not affect the yield of enamine (53- 64%, based on the aldehyde). Contrariwise, changing the ratio of amine (morpholine, piperidine, or pyrrolidine) to n-butyraldehyde from 1 1 to 2 1 boosted the yields from 52-57 % to 80-85 %. The authors interpret these data as indicating that the cyclic amines form aminals with n-butyraldehyde, while the open-chain do not. Infrared evidence is stated as having shown that the aminal originates not from attack of excess amine on the enamine, which is stable under the conditions of the reaction, but from the N-hemiacetal (17). 

Figure 8-5. The Hoechst AG and Rhone Poulenc process for producing butyraldehydes from propene (1) reactor, (2) catalyst separation, (3) stripper (using fresh syngas to strip unreacted propylene to recycle), (4) distillation.

The submitters used a commercial grade of butyraldehyde from Eastman Organic Chemicals the checkers used the butyraldehyde of the same grade from Wako Pure Chemical Industries Ltd. (Japan) and distilled it before use, b.p. 72-74°. 

This type of process represents the ideal biphasic method as long as the product can be extracted without contamination from the catalyst and catalyst immobilization solvent. This technique is employed commercially for the production of butyraldehyde from propene, carbon monoxide and hydrogen which is described in detail in Chapter 11 [3],... 

The hydroformylation reaction, also known as the oxo reaction, is used extensively in commercial processes for the preparation of aldehydes by the reaction of one mole of an olefin with one mole each of hydrogen and carbon monoxide. The most extensive use of the reaction is in the preparation of normal- and iso-butyraldehyde from propylene. The ratio of the amount of the normal aldehyde product to the amount of the iso aldehyde product typically is referred to as the normal to iso (N I) or the normal to branched (N B) ratio. In the case of propylene, the normal- and iso-butyraldehydes obtained from propylene are in turn converted into many commercially-valuable chemical products such as n-butanol, 2-ethyl-hexanol, trimethylol propane, polyvinylbutyral, n-butyric acid, iso-butanol, neo-pentyl glycol,... 

The manufacture of linear low-density polyethylene (LLDPE) by slurry polymerization in hexane (see Sections 6.2 and 6.8) is carried out by Hoechst, Mitsui, and a number of other chemical manufacturers in a series of continuous stirred tank reactors. The manufacture of butyraldehyde from CO, H2, and propylene using a soluble rhodium phosphine complex (see Sections 5.2 and 5.5) is also carried out in a continuous stirred tank reactor. 

Reaction in two-phase liquid-liquid systems. The Ruhrchemie process for the manufacture of butyraldehyde from propylene uses a water-soluble rhodium catalyst, while the product butyraldehyde forms an immiscible organic layer. Separation of the product from the catalyst is thus easily accomplished (see Section 5.2.5). 

Application To produce normal and iso-butyraldehyde from propylene and synthesis gas (CO + H2) using the LP Oxo SELECTOR Technology, utilizing a low-pressure, rhodium-catalyzed oxo process. 

The largest volume hydroformylation reaction converts propylene into n-butyraldehyde, from which is made 1-butanol for solvents, or 2-ethylhexanol (the phthalate ester of which has been widely used as a plasticizer for PVC) via an aldol condensation. Estimated world production of butanol is approaching 2 Mt/a. 

Unexpectedly, aziridine was found to be particularly good for the preparation of amides which could be reduced with LiAlH4 in high yield to aldehydes. With butyric acid, the yields of butyraldehyde from various amides were dimethylamide 25%, diethylamide 22%, diisopropylamide no reaction, A -methyl-phenylamide 58%, piperidide 33%, pyrrolidide 16% and aziridide 88%.A later report indicated that yields of 40-80% of the aldehyde could be attained even with a 100% excess of L1A1H4 if aziridides were used. ... 

The Ruhrchemie AG oxo process is a commercial one for the manufacture of -butyraldehyde from propylene and synthesis gas. The reaction is ... 

Srinivas, G. and Chuang, S., An in-situ infrared study of the formation of n- and iso-butyraldehyde from propylene hydroformulation on Rh/Si02 and sulfided Rh/Si02, J. Catal., 144 131-147 (1993). 

The Ruhrchemie/Rhone-Poulenc Oxo process (Figure 4.1, Scheme 4.1) was developed for the synthesis of butyraldehyde from propylene and synthesis gas, where the water-soluble tris(m-sulfonated-phenyl)phosphine (TPPTS)-modified rhodium catalyst operates in the aqueous phase [14]. 

Following earlier contacts Ruhrchemie AG (RCH), now a part of Celanese AG, and Rhone-Poulenc joined forces in 1982 to develop a continuous biphase hydrofor-mylation process for the production of n-butyraldehyde from propene. 

Test runs with low P/Rh ratios and Rh concentrations while hydroformylating DCP showed excellent membrane separation results but decreasing activity data. This failure in the optimization approach of the hydroformylation and membrane separation step without regard to long-term stability again underlines a basic problem in catalyst development, the coincidental consideration of different contradictory circumstances. A second series with a high P/Rh ratio of 100 was performed with the same catalyst system and butyraldehyde from the hydroformylation of propene as feed. 

Chemistry. The hydroformylation of allyl alcohol is illustrated in Eq. (58). The catalyst is a rhodium complex modified with triphenylphos-phine of the same type used for production of n-butyraldehyde from propylene in the oxo process. The reaction takes place in a toluene solution at approximately 2-3 atm pressure (15-30 psig) and 60°C (140 F). The conversion to 4-hydroxybutyraldehyde is 98% based on allyl alcohol with a selectivity of 79.1%. 

Aldehyde dehydrogenase (ALDH enzymes 14 and 19 in O Fig. 2.1) is responsible for the formation of butyraldehyde from butyryl-CoA and acetaldehyde from acetyl-CoA for the production of, respectively, butanol and ethanol. Different ALDH activities can be measured in a strain of solvent-producing clostridia (Bertram et al. 1990), and the... 

Figure 7.31 Three processes for synthesizing butyraldehyde from propylene, butanol,...

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