Chloral , oxidation

CCls CHO. A colourless oily liquid with a pungent odour b.p. 98°C. Manut actured by the action of chlorine on ethanol it is also made by the chlorination of ethanal. When allowed to stand, it changes slowly to a white solid. Addition compounds are formed with water see chloral hydrate), ammonia, sodium hydrogen sulphite, alcohols, and some amines and amides. Oxidized by nitric acid to tri-chloroethanoic acid. Decomposed by alkalis to chloroform and a methanoate a convenient method of obtaining pure CHCI3. It is used for the manufacture of DDT. It is also used as a hypnotic. 

When chlorine is passed into boiling ethanol, both chlorination of the methyl group and oxidation of the primary alcohol group to an aldehyde occur, giving trichloro-acetaldehyde or chloral ... 

Trichloroacetic acid is best prepared by the oxidation of chloral hydrate with fuming nitric acid ... 

Acetaldehyde, first used extensively during World War I as a starting material for making acetone [67-64-1] from acetic acid [64-19-7] is currendy an important intermediate in the production of acetic acid, acetic anhydride [108-24-7] ethyl acetate [141-78-6] peracetic acid [79-21 -0] pentaerythritol [115-77-5] chloral [302-17-0], glyoxal [107-22-2], aLkylamines, and pyridines. Commercial processes for acetaldehyde production include the oxidation or dehydrogenation of ethanol, the addition of water to acetylene, the partial oxidation of hydrocarbons, and the direct oxidation of ethylene [74-85-1]. In 1989, it was estimated that 28 companies having more than 98% of the wodd s 2.5 megaton per year plant capacity used the Wacker-Hoechst processes for the direct oxidation of ethylene. 

Trichloroacetic acid is manufactured in the United States by the exhaustive chlorination of acetic acid (38). The patent Hterature suggests two alternative methods of synthesis hydrogen peroxide oxidation of chloral (39) and hydrolytic oxidation of tetrachloroethene (40). 

Make acid yields coumaUc acid when treated with fuming sulfuric acid (19). Similar treatment of malic acid in the presence of phenol and substituted phenols is a facile method of synthesi2ing coumarins that are substituted in the aromatic nucleus (20,21) (see Coumarin). Similar reactions take place with thiophenol and substituted thiophenols, yielding, among other compounds, a red dye (22) (see Dyes and dye intermediates). Oxidation of an aqueous solution of malic acid with hydrogen peroxide (qv) cataly2ed by ferrous ions yields oxalacetic acid (23). If this oxidation is performed in the presence of chromium, ferric, or titanium ions, or mixtures of these, the product is tartaric acid (24). Chlorals react with malic acid in the presence of sulfuric acid or other acidic catalysts to produce 4-ketodioxolones (25,26). 

Arsenious oxide, trivalent antimony (73), sulfurous acid (74), hydrogen sulfide (75), stannous ion, and thiocianate (76) have been recommended for the titration of iodine. However, none of these appears to have a greater sensitivity for the deterrnination of minute quantities of iodine than thiosulfate. Organic compounds such as formaldehyde (77), chloral hydrate (78), aldoses (79), acetone (70,80), and hydroquinone have also been suggested for this purpose. 

Exposure occurs almost exclusively by vapor inhalation, which is followed by rapid absorption into the bloodstream. At concentrations of 150—186 ppm, 51—70% of the trichloroethylene inhaled is absorbed. MetaboHc breakdown occurs by oxidation to chloral hydrate [302-17-OJ, followed by reduction to trichloroethanol [115-20-8] part of which is further oxidized to trichloroacetic acid [76-03-9] (35—37). Absorbed trichloroethylene that is not metabolized is eventually eliminated through the lungs (38). The OSHA permissible exposure limit (PEL) eight-hour TWA concentration has been set at 50 ppm for eight-hour exposure (33). 

Adolph Baeyer is credited with the first recognition of the general nature of the reaction between phenols and aldehydes in 1872 ([2,5-7] [18], Table 5.1). He reported formation of colorless resins when acidic solutions of pyrogallic acid or resorcinol were mixed with oil of bitter almonds, which consists primarily benzaldehyde. Baeyer also saw resin formation with acidic and basic solutions of phenol and acetaldehyde or chloral. Michael and Comey furthered Baeyer s work with additional studies on the behavior of benzaldehyde and phenols [2,19]. They studied a variety of acidic and basic catalysts and noted that reaction vigor followed the acid or base strength of the catalyst. Michael et al. also reported rapid oxidation and darkening of phenolic resins when catalyzed by alkaline materials. 

In the oxidation of tns(2,2,3,3 tetrafluoropropyl) phosphite by oxygen, bromal exhibits a strong catalytic effect, whereas chloral is less effechve [101] (equation 93)... 

The starting semicarbazones were most often prepared directly from the a-keto acids. Godfrin proceeded from a-alkyl acetoacetates, which were converted by oxidation with nitrosylsulfuric acid to a-keto-acid oximes and the latter transformed to semicarbazones or thioseraicarbazones by applying semicarbazide or thiosemicarbazide. For glyoxylic acid semicarbazone a very convenient procedure was employed, making use of the hydrolysis of nonisolated chloral semicarbazone. ... 

Typical non-enolising aldehydes are formaldehyde and benzaldehyde, which are oxidised by Co(III) Ce(IV) perchlorate and sulphate , and Mn(III) . The main kinetic features and the primary kinetic isotope effects are the same as for the analogous cyclohexanol oxidations (section 4.3.5) and it is highly probable that the same general mechanism operates. kif olko20 for Co(III) oxidation of formaldehyde is 1.81 (ref. 141), a value in agreement with the observed acid-retardation, i.e. not in accordance with abstraction of a hydroxylic hydrogen atom from H2C(OH)2-The V(V) perchlorate oxidations of formaldehyde and chloral hydrate display an unusual rate expression, viz. 

Newman LM, LP Wackett (1991) Fate of 2,2,2-trichloroacetaldehyde (chloral hydrate) produced during trichloroethylene oxidation by methanotrophs. Appl Environ Microbiol 57 2399-2402. 

Triisopropyl-1,3,5-dioxaphosphorinane (26) and its sulfide react with chloral, p-fluorobenzaldehyde, and acetaldehyde [Eq. (18)]. In the latter case, the hydroxymethyl derivative (29) (R = Me) was obtained. The reaction with chloral and p-fluorobenzaldehyde does not stop at the addition stage, but proceeds further to form the oxides (30) (R = CCI3,p-F-C6H4) (81IZV2776). 

Our Form II has two uncommon features. In the first place it contains two hydroxyl groups attached to the same carbon but we have that in chloral hydrate. In the second place there is an ethylene oxide oxygen linkage. This might be called an alpha lactone with the water not split off. This formation of a ring structure is believed to account for the reversal of the sign of rotation. It is well known that the formation of the lactide from lactic acid, while not a lactone formation in the same... 

By analogy with chloral and monochloroacetaldehyde it is to be expected that fluoroacetaldehyde might readily form a hydrate, and it was in this form that the fluoroacetaldehyde was obtained in small yields by the above-mentioned oxidation of F.E.A. 

Trichloroethylene oxide (trichlorooxirane, 10.89, Fig. 10.22) has received particular attention due to its toxicological significance and the widespread use of its parent compound trichloroethylene (10.87) [153] [155]. Chloral... 

Fig. 10.22. Simplified reactivity and metabolism of trichloroethylene (10.87) to chloral (10.88) and to trichloroethylene oxide (10.89), followed by rearrangement reactions and/or hydrolysis...

Figure 2 shows a simplified process flow diagram for halogenated aliphatic acid production facilities [8]. Halogenated aliphatic acids include chlorinated aliphatic acids and their salts, for example, TCA, Dalapon, and Fenac herbicides. Chlorinated aliphatic acids can be prepared by nitric acid oxidation of chloral (TCA) or by direct chlorination of the acid. The acids can be sold as mono- or dichloro acids, or neutralized to an aqueous solution with caustic soda. The neutralized solution is generally fed to a dryer from which the powdered product is packaged. 

Diloxanide was first prepared by the reaction of 4-hydroxy-A-methyl aniline with sodium cyanide and chloral hydrate in the presence of a base [9]. Furoic acid was prepared by the hypochlorite oxidation of... 

Die Oxidation von (Z)-Chloral-oxim mit Distickstofftetroxid liefert 3,4-Bis-[trichlormethyl]-... 

Amino-l,2,4-triazolo[l,5-a]pyrimidines may also be diazotized and coupled [66JCS(C)2031 73GEP2304285], but are not reactive toward ni-troso compounds, chloral, ethylene oxide (66 CB2237), and DMF dimethyl acetal (90ZC320). 

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. 

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