Acrolein Methionine

When exposed to sunlight, it is converted to a white insoluble resin, disacryl. Oxidized by air to propenoic acid small amounts of hy-droquinone will inhibit this. Bromine forms a dibromide which is converted by barium hydroxide into DL-fructose. The acrid odour of burning fats is due to traces of propenal. It is used in the production of methionine and in controlled polymerization reactions to give acrolein polymers. ... 

Of these producers, Atochem, Degussa, and Daicel are reported to be in the merchant acrolein business. Union Carbide suppHes only the acrolein derivative markets. Rhc ne-Poulenc also produces acrolein, primarily as a nonisolated intermediate to make methionine. A number of other small scale plants are located worldwide which also produce acrolein as an intermediate to make methionine. 

The significance of industrial acrolein production may be clearer if one considers the two major uses of acrolein—direct oxidation to acryUc acid and reaction to produce methionine via 3-methyhnercaptopropionaldehyde. In acryUc acid production, acrolein is not isolated from the intermediate production stream. The 1990 acryUc acid production demand in the United States alone accounted for more than 450,000 t/yr (28), with worldwide capacity approaching 1,470,000 t/yr (29). Approximately 0.75 kg of acrolein is required to produce one kilogram of acryUc acid. The methionine production process involves the reaction of acrolein with methyl mercaptan. Worldwide methionine production was estimated at about 170,000 t/yr in 1990 (30). (See Acrylic ACID AND DERIVATIVES AmINO ACIDS, SURVEY.)... 

Addition of Mercaptans. One of the largest uses of acrolein is the production of 3-methylmercaptopropionaldehyde [3268-49-3] which is an intermediate in the synthesis of Dj.-methionine [59-51-8] an important chicken feed supplement. 

Methylmercaptopropionaldehyde is also used to make the methionine hydroxy analog CH2SCH2CH2CH(OH)COOH [583-91 -5] which is used commercially as an effective source of methionine activity (71). AH commercial syntheses of methionine and methionine hydroxy analog are based on the use of acrolein as a raw material. More than 170,000 tons of this amino acid are produced yearly (30) (see Amino acids). One method for the preparation of methionine from acrolein via 3-methyhnercaptopropionaldehyde is as follows. 

Chemical Production. Glyciae, DL-methionine, and dl-alanine ate produced by chemical synthesis. From 1964 to 1974, some glutamic acid was produced chemically (48). The synthetic amino acid with the largest production is DL-methionine from actoleia (see Acrolein and derivatives). The iadustrial production method is shown ia the foUowiag (210). 

Hydroxy-4-methylthiobutyric acid [583-91 -5] the hydroxy analogue of the amino acid methionine, is manufactured by acid hydrolysis of 3-methylthiopropionaldehyde cyanohydrin [17773-41-0] which is produced by the reaction of methyl mercaptan with acrolein (qv). 

The conjugate addition of a thiol, methanethiol, to the a,(5-unsaturated aldehyde acrolein may be used in the synthesis of the amino acid methionine. Under basic conditions, the nucleophile will be the thiolate anion, and 1,4-addition leads to the thia-aldehyde. Methionine may then be obtained via... 

Problem 21.4 Outline the preparation of (a) methionine from acrolein by the Strecker synthesis (Problem 21.2(e)), (b) glutamic acid by the phthalimidomalonic ester synthesis (Problem 21.2(c)]. ... 

ACROLEIN AND DERIVATIVES. Acrolein (2-propenal), C3H4O, is the simplest unsaturated aldehyde (CH2=CHCHO). The primary characteristic of acrolein is its high reactivity due to conjugation of the carbonyl group with a vinyl group. More than 80% of the refined acrolein that is produced today goes into the synthesis of methionine. Much larger quantities of crude acrolein are produced as an intermediate in the production of acrylic acid. More than 85% of the acrylic acid produced worldwide is by the captive oxidation of acrolein. 

Presently, worldwide refined acrolein nameplate capacny is about 113,000 t yr. Degussa has announced a capacity expansion in the United States by building a 36.000 t/yr acrolein plant in Theodore. Alabama to support their methionine business. The key producers of refined acrolein are Union Carbide (United States), Degussa (Germany i, Atochem (France), and Daicel (Japan). 

DL-Methionine AMINO ACIDS Synthesis from acrolein and mercaptan First limiting amino acid for soybean... 

Methionine. Methionine is an essential amino acid that is used in animal feed. The key ingredients are HCN or NaCN, methyl mercaptan, acrolein and NH4HCO3. In 2003 global capacity was 450,000 to 500,000 tonnes per year. 

Recent estimates of the atmospheric loading rate of acrolein from sources in the United States were not located. Anderson (1983) estimated the total loading rate of acrolein in 1978 to be 91,450 pounds from facilities involved in its production and use as a chemical intermediate. Loading rates from various industrial sources were as follows acrylic acid manufacturers, 15,175 pounds refined acrolein and glycerin manufacturers, 55,660 pounds methionine manufacturers, 18,150 pounds and miscellaneous intermediate uses, 2420 pounds. These loading rates were based on a total production volume of 350 million pounds for acrolein in 1978, with 87% of this volume consumed in the production of acrylic acid and its derivatives. 

Commercial acrolein is an intermediate in the manufacture of several products, in particular D,L-methionine, used as an additive in animal feeds. For the most part however it is directly oxidized to acrylic acid, without being separated and recovered as a pure material. The acid is mainly esterified to methyl and other acrylates, with the remainder being directly used for the manufacture of polymers. Acrylate esters are currently the final destination of most acrolein produced in the world. They readily form homopolymers and copolymerize with methacrylates, styrene, vinyl acetate and acrylonitrile to yield a range of prized products, characterized by excellent clarity, stability to UV light and aging, and good pigmentability. 

Glycine can be prepared in 73% yield from HCN, CH2O and (NH4>2COj [30] (Equation (52)). Methionine is obtained from acrolein, NHj. HCN and CH3SH, via an hydantom intermediate ... 

Acrolein is used as an intermediate in the manufacture of glycerol, polyurethane, polyester resins, methionine, pharmaceuticals, and herbicides, and has been used in military poison gas mixtures. 

As yet methionine, the other amino acid in which cereals are deficient, is only produced from pentaerythritol or acrolein by synthetic means, not by fermentation [71], which yields the DL product (e.g., Eq. 16.29). 

Methional results from a Strecker degradation of methionine. It is at the origin of formation of methanethiol (Q.2), dimethyl disulfide (Q.14) and acrolein (C.16). 

Thus, if the amino acid (Figure 8.23) is alanine (R3 = -CH3), widely represented in must and wine, the corresponding aldehyde is ethanal. If the amino acid is methionine (R4 = CH3-S-CH2-CH2-), which is certainly only present in small quantities but is reputed to be highly reactive with carbonylated compounds, then methional, or -methyl-S-propanal, is produced. This compound is thermally unstable and evolves rapidly, via a Retro-Michael reaction, into acrolein and methanethiol (Figure 8.28). These smell of cooked cauliflower, wet dog, etc. In wine, part of the methional returns to methionol via catalyzed reduction by alcohol dehydrogenase with NADH. 

The Degussa methionine process exemplifies, how many industrial procedures gain attraction through the elegance of how they are conducted. In summary, methionine is formed from equimolar portions of acrolein, methanethiol, hydrogen cyanide and water. The yields of all the reaction steps exceed 90% (Fig. 4.14 and Fig. 4.15). 

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