2.2.2- Trichloroethanol

Trichloroethanol may be used analogously. The 2,2,2-trichloroethyl (Tee) group is best removed by reduction with copper-zinc alloy in DMF at 30 °C (F. Eckstein, nucleic acid synthesis see section 4.1.1. 

Dicofol [54532-36-4] l,l-bis(/)-chlorophenyl)-2,2,2-trichloroethanol, R = Cl (139), is a white crystalline soHd (mp 79°C). This compound is insoluble in water and soluble in organic solvents, and in the presence of alkaU forms the inactive/),/) -dichloroben2ophenone and chloroform. Dicofol is a long-lasting acaricide and is active against all stages of mites. The rat oral LD qS are 809, 684 mg/kg. 

Chemical Name 2,2,2-trichloroethanol dihydrogen phosphate monosodium salt Common Name Trichloroethyl phosphate monosodium salt Structural Formula ... 

Pekari K, Aitio A. 1985b. Method 30 Determination of 2,2,2-trichloroethanol in urine. LARC Sci Publ 68 473-478. 

Activated esters of halogenated alcohols, such as 2-chloroethanol, 2,2,2-trifluoroethanol, and 2,2,2-trichloroethanol, have been often used as substrate for enzymatic synthesis of esters, owing to an increase in the electrophilicity (reactivity) of the acyl carbonyl and avoid significant alcoholysis of the products by decreasing the nucleophilicity of the leaving alcohols. ... 

Block copolymers were synthesized by a combination of fipase-catalyzed polymerization and atom transfer radical polymerization (ATRE). " " At first, the polymerization of 10-hydroxydecanoic acid was carried out by using lipase CA as catalyst. The terminal hydroxy group was modified by the reaction with a-bromopropionyl bromide, followed by ATRP of styrene using CuCE2,2 -bipyridine as catalyst system to give the polyester-polystyrene block copolymer. Trichloromethyl-terminated poly(e-CL), which was synthesized by lipase CA-catalyzed polymerization with 2,2,2-trichloroethanol initiator, was used as initiator for ATRP of styrene. 

If the carbonyl group must be regenerated under nonhydrolytic conditions, (3-halo alcohols such as 3-bromopropane-l,2-diol or 2,2,2-trichloroethanol can be used for acetal formation. These groups can be removed by reduction with zinc, which leads to (3-elimination. 

A. l-Phenyl-2,2,2-lrichloroethanol. In a 1-1. round-bottomed-flask fitted with a mechanical stirrer, a thermometer, and a powder funnel is placed a solution of 212 g. (2.00 moles) of freshly distilled benzaldehyde in 400 g. (270 ml., 3.35 moles) of chloroform. The mixture is cooled in an ice bath, and 123 g. of commercial powdered potassium hydroxide is added with stirring at such a rate that the temperature of the solution does not exceed 45° (1-1.5 hours). The reaction mixture is stirred and kept at 40-50° for an additional hour and then poured into a solution of 60 ml. of sulfuric acid in 3 1. of water. The resulting two-phase mixture is transferred to a separatory funnel and extracted with three 250-ml. portions of chloroform (a small amount of insoluble, black resinous material is discarded). The combined organic layers are washed with three 100-ml. portions of aqueous 10% sodium carbonate, dried over anhydrous magnesium sulfate, and filtered into a 1-1. flask. The solvent is removed under reduced pressure on a hot water bath. The residue is transferred to a 250-ml. flask and distilled under reduced pressure to give l-phenyl-2,2,2-trichloroethanol, b.p. 155-165° (26 mm.), 90-100° (0.5 mm.) (Notes 1 and 2). The yield is 170-180 g. (38-40%). 

The procedure for the preparation of 1-phenyl-2,2,2-trichloro-ethanol is based on the work of Bergmann, Ginsburg, and Lavie.3 l-Phenvl-2,2,2-trichloroethanol has also been prepared from phenylmagnesium bromide and chloral.4... 

M. Perttila, Vibrational spectra and normal coordinate analysis of 2,2,2 trichloroethanol and 2,2,2 trifluoroethanol. Spectrochim. Acta Part A 35, 585 592 (1978). 

V. Moulin, A. Schriver, L. Schriver Mazzuoli, and R Chaquin, Infrared spectrum of 2,2,2 trichloroethanol isolated in gas matrices. Ab initio optimization of conformers and potential energy calculations. Chem. Phys. Lett. 263, 423 428 (1996). 

The reduction of carbonyl compounds with trialkyaluminum reagents has been known for several decades (140,141). Meerwein and co-workers observed that chloral is reduced to 2,2,2-trichloroethanol with triethylaluminumetherate (142). Organoaluminum reagents can function as reducing agents if they contain A1—H bonds or if they have hydrogen at a p (particularly a branched) position. 

The metabolism of 1,1,1,2-tetrachloroethane (11.26), a representative aliphatic chlorohydrocarbon, provides an example of mechanistic ambiguity. When administered to mice, ca. 40-45% of the dose was excreted unchanged in the expired air, whereas ca. 30% and 4% of the dose was excreted in urine and feces as 2,2,2-trichloroethanol and 2,2,2-trichloroacetic acid, respectively [59]. Both Pathways a and b in Fig. 11.3, together with the redox reactions shown in Fig. 11.3, c, can explain these results. 

Bromoacetyl fluoride, 45, 6 Bromobenzene, condensation with 1 -phenyl- 2,2,2 - trichloroethanol, 48, 28... 

Archer, T.E. The effect of ultraviolet radiation filtered through Pyrex glass upon residues of dicofol [Kelthane l,l-bis(/r-chlorophenyl)-2,2,2-trichloroethanol on apple pomance. Bull Environ. Contam. Toxicol, 12(2) 202-203, 1974. 

Vaidyanathaswamy, R., Dureja, P, and Mukerjee, S.K. Photoinduced reaction Part III — Photodegradation of p,p -dichlorodiphenyl-2,2,2-trichloroethanol (Dicofol), an important miticide, Indian. J. Chem., 20B 866-869, 1981. 

Scheldt and co-workers have also illustrated the oxidation of activated alcohols to esters [132], Oxidations of alcohols such as 260 provide the electrophile (acyl donor) for a nucleophilic alcohol 261. Esters 262 are derived from propargylic, allylic, aromatic, and hetero-aromatic substrates (Table 20). The nucleophilic alcohol scope includes MeOH, n-BuOH, f-BuOH, 2,2,2-trichloroethanol, 2-methoxyethanol, and 2-(trimethylsilyl) ethanol. 

Higher plants also effect such reductions. Nicotiana Tabacum accumulates in its leaves considerable amounts of the /S-n-glucoside and /S-gentiobioside of 2,2,2-trichloroethanol if the plants are cultivated in a nutrient medium containing chloral hydrate. ... 

Merck scientists made changes to this process, resulting in fewer equivalents of acet-ylide and chiral ligand without the use of Ai-protection (Chen et al., 1998). In a general procedure, a solution of the chiral ligand (1.5 equivalents) is treated with either dimethyl or diethylzinc at 0°C to room temperature (Scheme 6.4). This mixture is stirred for 1 h followed by the addition of an additive. Most of the additives studied are either carboxylic acids or alcohols. The range of ee values from the different additives is 71.6% (2,2-dimethylpropanoic acid) to 96% (2,2,2-trichloroethanol). This solution is mixed... 

The /.5-phosphanes derived from l-aryl(or heteroaryl)-2,2,2-trichloroethanols are even more stable and are converted into fluorides 12 only on heating above 100 C.18... 

NMO NMP Nu PPA PCC PDC phen Phth PPE PPTS Red-Al SEM Sia2BH TAS TBAF TBDMS TBDMS-C1 TBHP TCE TCNE TES Tf TFA TFAA THF THP TIPBS-C1 TIPS-C1 TMEDA TMS TMS-C1 TMS-CN Tol TosMIC TPP Tr Ts TTFA TTN N-methylmorpholine N-oxide jV-methyl-2-pyrrolidone nucleophile polyphosphoric acid pyridinium chlorochromate pyridinium dichromate 1,10-phenanthroline phthaloyl polyphosphate ester pyridinium p-toluenesulfonate sodium bis(methoxyethoxy)aluminum dihydride (3-trimethylsilylethoxy methyl disiamylborane tris(diethylamino)sulfonium tetra-n-butylammonium fluoride f-butyldimethylsilyl f-butyldimethylsilyl chloride f-butyl hydroperoxide 2,2,2-trichloroethanol tetracyanoethylene triethylsilyl triflyl (trifluoromethanesulfonyl) trifluoroacetic acid trifluoroacetic anhydride tetrahydrofuran tetrahydropyranyl 2,4,6-triisopropylbenzenesulfonyl chloride 1,3-dichloro-1,1,3,3-tetraisopropyldisiloxane tetramethylethylenediamine [ 1,2-bis(dimethylamino)ethane] trimethylsilyl trimethylsilyl chloride trimethylsilyl cyanide tolyl tosylmethyl isocyanide meso-tetraphenylporphyrin trityl (triphenylmethyl) tosyl (p-toluenesulfonyl) thallium trifluoroacetate thallium(III) nitrate... 

For two-carbon alcohols, LUMO decreases as the number of chlorines increases. As LUMO decreases, the ability of a compound to undergo reduction increases therefore, an increase in chlorine increases the reactivity of the molecule. The dataset contains 2,2,2-trichloro-l,l-ethanediol 2,2,2-trichloroethanol 2,2-dichloroethanol and 2-chloroethanol. LUMO represents 99.85% of the variance in the linear regression equation. The probability of getting a correlation of -0.9992 for a sample size of four is less than 1%. 

---