1 -Chloro-1 ,2-Dibromoethan

Fig. 3 Chart illustrating the superconducting transition temperatures as a function of solvent and anion in the KL-(BEDT-TTF)M(CF3)4(l,l,2-trihaloethane) (M = Cu, Ag and Au) series. 1120 is 1,1,2-trichoroethane, lBrl2Cl is l-bromo-l,2-dichloroethane, llC12Bris 1,1-dichloro-2-bromoethane, lC112Br is 1-chloro-1,2-dibromoethane and 112Bris 1,1,2-tribromoethane...

Carbon tetrachloride, 0322 Carbon tetrafluoride, 0349 Carbon tetraiodide, 0525 f 1-Chlorobutane, 1637 f 2-Chlorobutane, 1638 f Chlorocyclopentane, 1923 f l-Chloro-l,l-dilluoroethane, 0731 Chlorodilluoromethane, 0369 f Chloroethane, 0848 Chloroform, 0372 f Chloromethane, 0432 f l-Chloro-3-methylbutane, 1986 f 2-Chloro-2-methylbutane, 1987 f Chloromethyl ethyl ether, 1246 f Chloromethyl methyl ether, 0850 f l-Chloro-2-methylpropane, 1639 f 2-Chloro-2-methylpropane, 1640 f 1-Chloropentane, 1988 f 1-Chloropropane, 1243 f 2-Chloropropane, 1244 f l-Chloro-3,3,3-trifluoropropane, 1127 1,2-Dibromoethane, 0785 Dibromomethane, 0395... 

Azine approach. l-(2-Chloroethyl)uracil is cyclized to the corresponding oxazoline (266) in the presence of DBU (77MI42901). By analogy, treatment of 2,4-(l//,3//)quinazolinedione with 1,2-dibromoethane or reacting the 3-(2-chloroethyl) homologue (267) with sodium ethoxide leads to oxazoline fusion. The same product is formed from 2-chloro-3-(2-... 

Derivatives of 1-methyl-3//-l,4-benzodiazepine-2,5(l/I,4/I)dione (193) were synthesized by ring closure of substituted 2-(A-chloro-acetyl-A-methylaminoJbenzamides with sodium methoxide in methanol.209 Treatment of 193 with lithium aluminum hydride led to reduction of both carbonyl groups.209 The parent tetrahydro system (194) has been prepared by reaction of the tosylate (195) with 1,2-dibromoethane followed by hydrolysis.210 The preparation of 194 by another route had previously been noted.204 Reaction of 194 with formaldehyde or benzaldehyde gave a compound formulated as 196 (R = H or C6H5).210 Hydrolysis of 196 (R = C6H5) with 0.1 N hydrochloric acid gave 194 while 196 (R = H) was not hydrolyzed at this acidity. 

Alkenyllithiums generated from trisylhydrazones react with electrophiles such as primary alkyl bromides, aldehydes, ketones, dimethylformamide, CO2, chloro-trimethylsilane, or 1,2-dibromoethane to furnish substituted alkenes, allylic alcohols, a,(3-unsaturated aldehydes, a,P-unsaturated acids, alkenylsilanes, or alkenyl bromides, respectively, as exemplified below for the preparation of an allylic alcohol and an a,P-unsaturated aldehyde. ... 

The dimeric mono(cyclooctatetraenyl)lanthanide chlorides [(COT)Ln(/r-Cl)(THF)2]2 are long known and still represent the most useful precursors in (COT)Ln chemistry. A recently reported alternative preparation of the Sm derivative involves the reaction of samarium metal with COT in THF in the presence of a small amount of I IgCL. The molecular structure of [(COT)Sm(/i-CI)(TT 11 )2]2 has been determined.805,806 Iodo-(cyclooctatetraenyl)lanthanide iodides of the type (COT)Lnl(TIIF) (Ln = La, Ce, Pr, n = 3 Ln = Nd, n = 2 Ln = Sm, n l) are readily accessible in a one-pot reaction of metallic lanthanides with COT in the presence of an equimolar amount of iodine. Bromo- and chloro-bridged binuclear complexes of samarium, [(COT)Sm(/.t-X)(THF )2]2 (X = Br, Cl), were also prepared by the reaction of samarium metal with COT in the presence of 1,2-dibromoethane or Ph3PCl2, respectively.807 Alternatively, the iodo complexes (COT)LnI(THF)3 (Ln = Nd, Sm) can be synthesized directly from the lanthanide triiodides and K2COT. The molecular structure of (COT)Ndl(THF)3 has been determined by X-ray diffraction.808 A clean preparation of the monomeric half-sandwich complex (GOT)TmI(THF)2 involves treatment of Tml2 with equimolar amounts of COT in THF at room temperature (Scheme 227). The product was isolated as red crystals in 75% yield.628... 

Polyhalogenoalkanes and dihalogenoethanes have been extensively used to prepare, under PTC conditions, poly(pyrazol-l-yl)alkanes (number of pyrazoles = 2,3,4) and l,2-di(pyrazol-l-yl)ethanes <840PP299,86H(24)2233>. The reaction of pyrazoles with 1,2-dibromoethane in PTC conditions affords a mixture of 7V-ethenylpyrazoles and 1,2-bispyrazolylethanes <88JHC77i> it is also possible to carry out the reaction in two steps through l-chloro-2-(pyrazol-l-yl)ethane. Indazole affords a mixture of l,2-bis(indazol-l-yl)ethane and l-(indazol-l-yl)-2-(indazol-2-yl)ethane. 

Addition methods were used for the determination of m-saturated compounds and olefins. The methods are based on the additions of bromine to unsaturated bonds, and the waves for the brominated compounds corresponding to the reduction of o, j8-dibromides (involving elimination) are measured. Their heights are proportional to the concentration of the unsaturated compound. Thus vinylchloride and 1,2-dichloroethylene were transformed into l-chloro-l,2-dibromoethane and l,2-dichloro-l,2-dibromoethane, by the action of a 3 M solution of bromine in methanol saturated with sodium bromide. The excess of bromine was removed with ammonia and the polarographic analysis was performed with sodium sulphite or lithium chloride as a supporting electrolyte. On the other hand, acetylene, vinyl-chloride, 1,2-dichloroethylene and 1,1,2-trichloroethylene were determined ) after a 24 hr reaction with bromine in glacial acetic acid (1 1). The excess bromine was removed with a stream of nitrogen or carbon dioxide. An aliquot portion is diluted (1 10) with a 3 M solution of sodium acetate in 80 per cent acetic acid and after deaeration the curve is recorded. 

An aq. soln. of Na-sulfite and NaOH or KOH added with stirring at 65-72 to l,l,l-trifluoro-2-chloro-2,2-dibromoethane with distillation of the product -> l,l,l-trifluoro-2-chloro-2-bromoethane. Y 80-90%. H. Madai and R. Muller, J. pr. 19, 83 (1963). 

These properties coincide with those previously published for I, prepared by reaction of thiomorpholine with 2-chloro-ethanol [12]. l,2-Ethane-N,N -bis(thiomorpholine) (HI) crystallized from its concentrated chloroform extract, and was recrystallized from benzene m.p. 103-105 °C yield 15 - 20%. Ill has also been prepared by reaction of thiomorpholine with 1,2-dibromoethane [13]. 

Transition metal-catalysed carbene abstraction has been reported once, whereby a-oxo Au carbenes generated on oxidation of terminal alkynes are prone to abstract halogen from solvents such as 1,2-dichloroethane and 1,2-dibromoethane. This method constitutes an attractive approach for preparing chloro- or bromo-methyl ketones in one step starting from terminal alkynes. 

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