Chemical synthesis ethyl acetate

Table 9.2 summarizes the uses of acetic acid. Vinyl acetate is another top 50 chemical. Acetic anhydride is used to make cellulose acetate and at times has been in the top 50 chemicals itself. Cellulose acetate is a polymer used mainly as a fiber in clothing and cigarette filters. Ethyl acetate is a common organic solvent. Acetic acid is used as a solvent in the manufacture of terephthalic acid (TA) and dimethyl terephthalate (DMT), which are monomers for the synthesis of poly(ethylene terephthalate), the polyester of the textile industry. A minor household use of acetic acid is as a 3-5% aqueous solution, which is called vinegar. 

In a similar approach, Kasture and coworkers describe the use of neat substrate (ethyl acetate both as alcohol donor and as the reaction medium) in the preparation of chirally pure S-(-)-l,4-benzodioxan-2-carboxylate, an important drug intermediate used in the synthesis of doxazosin mesylate, from racemic l,4-benzodioxan-2-carboxylic acid [138]. Again, CaLB catalyzed the transesterification reaction with good enanhoselectivity (E = 160) and acceptable enantiomeric excess (>95%) and chemical yield (50%). 

Other important raw material uses of ethyl alcohol are conversion to esters and ethers, vinegar, ethyl chloride, butadiene, styrene, and chloral (for DDT). Nearly all the new developments in chemicals from ethyl alcohol, particularly the four-, six-, and eight-carbon derivatives are based on alcohol derived from petroleum. The butyl alcohol and butyl acetate so made supplement the production by fermentation and from oxidation of hydrocarbons and synthesis gas operations. The consumption of ethyl alcohol for all industrial uses (denatured alcohol) exceeded 1.2 billion pounds (100% basis) in 1950. More than 700,000,000 pounds of this were made from petroleum. 

An interesting case of interproduct competition is that of the four original lacquer solvents—ethyl alcohol, butyl alcohol, ethyl acetate, and butyl acetate. These were once produced mainly by fermentation processes, but today all are also produced by synthesis from petroleum hydrocarbons. Moreover, in the past 30 years solvents have been developed from petroleum sources which are competing successfully with these materials even though the new compounds are not identical in all properties isopropyl alcohol competes with ethyl alcohol methyl isobutyl carbinol and n-propyl alcohol can replace butyl alcohol methyl ethyl ketone to a large extent supplants ethyl acetate and methyl isobutyl ketone can be substituted for butyl acetate. Thus, petroleum aliphatic chemicals have served both by displacement of source and replacement of end product to supplement and to compete with the fermentation solvents. 

The synthesis of sildenafil serves as an excellent example of the demands of commercial chemistry. The route described contains all of the desired attributes required in chemical development, namely a safe, robust route, a convergent synthesis and a high yielding process. The authors managed to improve the yield from 7.5 % in the medicinal chemistry to 75.8 % overall from pyrazole 3. The synthesis also has an exceptionally low environmental impact. Only toluene and ethyl acetate are organic waste while the other solvents (ethanol and tert-butanol) can be treated in the water plants. The synthesis has been... 

The first use of crystals to achieve asymmetric induction in a chemical reaction was reported by Penzien and Schmidt in 1969 [3]. In what the authors termed an absolute asymmetric synthesis because it occurs in the absence of any external source of optical activity, Penzien and Schmidt showed that the achiral compound 4,4 -dimethylchalcone 1 crystallizes spontaneously from ethyl acetate in the chiral space group P2i2121, and when enantiomorphously pure... 

Thus the homologation reaction can be used, for example, for the synthesis of acetaldehyde from methanol [48], propionic acid from acetic acid [47], or ethyl acetate from methyl acetate [50]. Styrene may be produced from toluene by oxidation to benzyl alcohol [51] and homologation to 2-phenylethanol, which in turn can be dehydrated to styrene. From the chemical point of view, the applications of homologation reactions are broad and useful. But, as mentioned before, low selec-... 

There are many examples of the application of CD or RD for esterification.f" Esterification of methanol or ethanol with acetic acid forms methyl acetate or ethyl acetate, respectively. Methyl acetate is important in the manufacture of polyesters and is an important solvent for cellulose while ethyl acetate is used in inks, fragrances, and pharmaceuticals. The manufacture of high-purity methyl acetate is difficult because of the equilibrium limitation and also the formation of azeotropes. The production of methyl acetate by Eastman Chemical Co. was the first commercial application of RD using a homogeneous liquid acid catalyst. Only one RD column and two smaller columns for processing sidestreams are required while in the conventional methyl acetate synthesis, two reactors and eight distillation columns are required. 

The medicinal chemistry synthesis produced 1300 L of waste per kilo of product, the majority of which was methylene chloride. After 4 year of chemical development, this had been reduced to 100 L/kg including a snbstantial reduction in methylene chloride use. However, a major step forward in implementing an environmentally friendly process was the introduction of a commercial route, which not only dramatically improved the yield but also set up the process for solvent recovery. In the mannfactnre of pharmaceuticals, diligent solvent recovery is very often required to fully optimize the environmental performance of a synthesis. The recovery of ethyl acetate and toluene was introdnced in 1998, the year Viagra was launched, and this was followed by the recovery of... 

CijHjjNjOj molecular wt. 325.41 c 70.13% h 7.12% N 12.91% O 9.83% Hofinann, Bot. Mus. Leaf. Harv. Univ, 20 194,1963 Ipomoea violaced) Stoll, Helvetica ChimicaActa 26 956,1943 (from lysergic add) Korn-feld,/ of the American Chemical Society j 6-. 5256,1954 (total synthesis) tetrahedra from ethyl acetate needles from benzene, mp 162,° sol. in water, alcohols mafeate Ermetrine), mp 167,° sol. in water, alcohol psychoptic at 2-10 rag oral (Hofmann, The Road to Eleusis, Harcourt Br. Jovan. 1978 i ooA, Journal of Psychedelic Druptw 147,1979) controlled, prescription... 

Phospholipase D (EC 3.1.4.4) is a lipolytic enzyme that hydrolyzes the terminal phosphodiester bond on PLs. Due to its ability to transfer the phosphatidyl moiety of glycerophospholipids to various alcohols (transphosphatidylation), PLD is also used to synthesize PLs with desired head groups that are poorly accessible via the chemical route (Figure 23.4). This ability has been utilized for the synthesis of natural PLs that are rare in nature, such as PG and PS. Novel types of PLs (phosphatidyl-X) have also been synthesized via PLD-mediated transphosphatidylation to add the amphiphilic properties of PLs to the acceptor compounds. These reactions are typically carried out in biphasic systems with water (containing PLD or a hydrophilic alcohol acceptor) and an organic solvent such as chloroform, ether, ethyl acetate, benzene, or toluene. 

Though in moderate yield, the reported conversion of ethanol to ethyl acetate by complex 14 and a related osmium dimer complex [37] by Gusev generated interest in the catalytic synthesis of ethyl acetate from ethanol because it is a widely used fine chemical. Very recently, Beller et al. [38] screened the catalytic activity of various known pincer complexes for this transformation and found thatTakasago s complex 15, known as Ru-MACHO catalyst, is very efficient and the reaction in the presence of a base resulted in very good TON (Table 1.4). 

Dlamylamine is a colorless to straw-colored liquid with an ommaniacal odor, which is composed of a mixture of amyl isomers. It is soluble in ethyl alcohol, methyl alcohol, ethyl ethers, ethyl acetate, acetone, aromatic and aliphatic hydrocarbons, fixed oils, mineral oil, oleic and stearic acids. It is insoluble in water and while soluble in hot paraffin and carnauba waxes, these solidify an coaling. It is a solvent for ails, resins, and some cellulose esters. Introduction of the amyl group imparts oil solubility to otherwise oil-insoluble substances. It is used as a corrosion inhibitor, and in chemical synthesis. 

At this moment, fractionating reactors are mostly studied and applied outside the fine-chemical field. Examples are the large-scale production of the fuel ethers MTBE and TAME via reactive distillation. Also, biocatalytic studies have been performed. Malcata and co-workers investigated the integration of ester formation by Upases and distillative separation of the final products ester and water [44]. A number of synthesis reactions have been studied such as the esterification of ethanol and acetic acid to form ethyl acetate and water [45] in an SMB reactor with chemocatalysts (acidic ion exchange resins). Another, fairly similar appUcation was presented by Kawase et al. [46] to manufacture an ester from 2-phenylethanol. Mensah and Carta [47] used a chromatography column with lipases immobilised on resin to produce esters as well. 

The synthesis of required imidazolium salt l-decyl-2-methyl-3-octadecylimidazolium bromide was achieved by the reaction of l-decyl-2-methylimidazole with octadecyl bromide in ethyl acetate [32]. The contents were first stirred at room temperature for 2 h under nitrogen followed by the increasing of the temperature to 55°C overnight. A white precipitate of imidazolium salt was obtained on cooling, which was filtered, washed extensively with ethyl acetate, and dried at room temperature under reduced pressure. Figure 10.1 shows the chemical structure of the imidazolium salt. 

This refers to the selectivity based on major chemical transformation and side reaction. For example, hydroformylation of vinyl acetate monomer with synthesis gas can yield two species (1) aldehydes, acetoxy propanals, and (2) ester, ethyl acetate, as shown in Figure 1.1. In this case, acetoxy propanals are the desired hydroformylation products, whereas ethyl acetate is formed by an undesired hydrogenation of vinyl acetate monomer. The chemoselectivity would therefore be decided by the relative amounts of the acetoxy propanals and ethyl acetate formed. 

An extension of the technology associated with carbonylation of methyl acetate, namely the use of synthesis gas rather than CO alone, enables the production of other members of the acetyl chemicals family, in particular ethyl acetate, and the important monomer, vinyl acetate, via a pivotal intermediate ethylidene diacetate (1,1-diacetoxyethane). 

Mesitylate esters are common intermediates in chemical synthesis and are very unstable. In order to monitor the extent of a reaction, it is often necessary to monitor all reaction species the precursor, mesylate intermediates, and end products. The mesylation reaction of 3-(2-isopropylphenyl)-l-hydroxy-1-R-propane (where R is a bulky chlorinated hydrocarbon) was followed on a diol column (A = 320 nm) using a 15-min 15/85 5/95 (75/25 hexane/toluene)/ethyl acetate gradient [883]. Intramolecular ring closure of the analyte occurred on the silica support at room temperature. Chromatography yielded a large, tailed cyclic ether peak followed by the mesylated material followed by the unieacted diol compound. Elution was complete in 14 min. The silica-facilitated reaction was greatly reduced when the system temperature was taken down to 10°C and was prevented when the system tenqterature was -30°C. 

---