1 -Bromo-2-chloroethane

The photolysis of chlorodiazirine was investigated in several cases. From chloromethyl-diazirine (232) vinyl chloride was formed as the stable primary product of stabilization of chloromethylcarbene, with acetylene and hydrogen chloride as secondary products. Some 1,1-dichloroethane was assumed to have been formed through a linear diazo compound by reaction with HCl. Added HBr yielded 1-bromo-l-chloroethane (76MI5Q800). 

Chloroethyl bromide (l bromo-2-chloroethane) [ 107-04-0j M 143.4, b Khi-lOO. Washed with cone H2SO4, water, 10% Na2C03 soln, and again with water, then dried with CaCl2 and fractionally distd before use. 

Substitution of somewhat more complex side chains on the imidazole nitrogen of the purines leads to CNS stimulant drugs that have also been used as vasodilators and antispasmodic agents. Thus, alkylation of theophyline (2) with ethyl bromoacetate followed by saponification of the product gives acephylline (9). Alkylation with l-bromo-2-chloroethane gives the 2-chloroethyl derivative (10). Reaction of that intermediate with amphetamine yields fenethylline (11). ... 

The presence of hydroxyl groups in the benzylidene sugars does not interfere with the reaction and by-products are usually minor. Suitable solvents other than carbon tetrachloride, include benzene and tetra-chloroethane. Epoxide, amide, and other commonly encountered functionalities in sugar derivatives are unaffected under the reaction conditions. The corresponding 6-bromo-4-benzoates are valuable intermediates... 

Formation of angular-substituted dimethylene-bisimidazole derivatives 386 has been achieved by reaction of the parent bisimidazole 385 with either l-bromo-2-chloroethane or 1,2-dibromoethane (Equation 102) <1997CJC28>. Reaction of the bisimidazole with a bis-chloroiminium salt has also been used to generate a related core structure <2006T731>. 

The Williamson ether synthesis remains the most practical method for the preparation of tetrahydrofurans, as can be exemplified by the two examples shown in the following schemes. A simple synthesis of 2-substituted tetrahydrofuran-3-carbonitriles 84 is achieved by generating the alkoxide under a phase transfer condition via reaction between 4-chlorobutyronitrile and non-enolizable aldehydes <00SL1773>. A synthesis of 2-alkylidene-tetrahydrofuran 85 was recorded, in which a dianion can be generated through treatment of the amide shown below with an excess of LDA, and is followed by addition of l-bromo-2-chloroethane. In this way, the more basic y-carbon is alkylated and leads eventually to the nucleophilic cyclization <00SL743>. 

A term used to designate the geometric arrangement of moieties attached to two adjacent atoms within a molecule. An example of a vicinal diol would be ethylene glycol (HOCH2CH2OH) and a vicinal dihalide would be 1 -bromo-2-chloroethane. 

The effects on human health of trifluoroacetic acid (TFA) from the oxidation of HFC-134a, halothane (l,l,l-trifluoro-2-bromo-2-chloroethane, used as an anesthetic), and some of the other CFC replacements, such as HCFC-123 and HCFC-124, have been of some... 

Problem 12.28 Sketch the nmr spectra of (a) 1,1-dichloroethane, (b) 1,1,2-trichloroethane, (c) 1,1,2,2-tetrachloroethane and (d) l-bromo-2-chloroethane. In each case indicate the staircase" curve of relative areas. 

The work with l-bromo-2-chloroethane allowed the influence of the nature of the halogen on its reactivity to be observed as either vinyl bromide or vinyl chloride are formed. The ratio of the chloride to the bromide in the products changed with the nature of the catalyst, being around 0.1 for sulphates of Ni, Co, Mn, Cu, Zn and for silica—alumina, 0.6 for alumina and 5 for KOH—Si02 [179]. 

Stereoisomers Structural isomers having an identical chemical constitution but exhibiting differences in the spatial arrangement of their atoms are called stereoisomers [7], One case of stereoisomerism, denoted asymmetric chirality, comprises molecules that are mirror images of each other. Such pairs of molecules are called enantiomers. Figure 1.2.3 illustrates the two chiral molecules of 1-bromo-1-chloroethane. The line in the middle represents a symmetry plane. Note that it is... 

For example, the rate of displacement of bromide by thiophenoxide ion in l-bromo-2-chloroethane is slowed down by a factor of 5 compared to substitution in the structurally similar 1-bromopropane (Equations 4.13 and 4.14).33 But the... 

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