74-96-4 Bromoethane

Services Reg. No. 74-96-4 Systematic name Bromoethane Synonym Ethyl bromide 

2 Structural and molecular formulae and relative molecular mass 

Bromoethane has limited commercial use, including that as an ethylating agent. It has been detected in ocean air as a result of its formation by marine algae (lARC, 1991). 

Bromoethane was tested for carcinogenicity in a two-year study in male and female 

Fischer 344 rats and B6C3Fi mice by inhalation. In male rats, there was a significant 

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Into the reaction flask is added 912g crystalline guaiacol and 1500g regular 48% HBr which is then slowly heated to reflux. The tepid water condenser is there to allow the bro-momethane that is formed to leave the reaction flask but is still cold enough to keep the other reactants in the reaction flask. The noxious bro-moethane condenses in the cold water condenser and drips into the chilled methanol in the collection flask. This will keep this bromoethane trapped so that the chemist will not die... 

This method is merely an application of the Grignard reaction but is a lot less troublesome because it uses really common chemicals. This method can be done as it was done in the reference where a phenylbutene was made using a bromopropane ( bromo-propane and bromoethane are cheap to purchase or can be made... 

C- (112, 113), 4- C- and 5- C-thiazoles (112) were prepared by the same general pathway from the corresponding " C-labeled 2-aminothiazoles synthesized by the Hantzsch cyclization of C-thiourea, l- C-2-bromoethanal, and 2- C-2-bromoethanal, respectively (112). A mixture of 4- and 5- C-thiazoles was prepared by the same general... 

Until It was banned in the United States in 1984 1 2 di bromoethane (ethylene dibromide orEDB)waspro duced on a large scale for use as a pesticide and soil fumigant... 

Vlayl fluoride [75-02-5] (VF) (fluoroethene) is a colorless gas at ambient conditions. It was first prepared by reaction of l,l-difluoro-2-bromoethane [359-07-9] with ziac (1). Most approaches to vinyl fluoride synthesis have employed reactions of acetylene [74-86-2] with hydrogen fluoride (HF) either directly (2—5) or utilizing catalysts (3,6—10). Other routes have iavolved ethylene [74-85-1] and HF (11), pyrolysis of 1,1-difluoroethane [624-72-6] (12,13) and fluorochloroethanes (14—18), reaction of 1,1-difluoroethane with acetylene (19,20), and halogen exchange of vinyl chloride [75-01-4] with HF (21—23). Physical properties of vinyl fluoride are given ia Table 1. 

Isoprene [78-79-5] (2-methyl-1,3-butadiene) is a colorless, volatile Hquid that is soluble in most hydrocarbons but is practically insoluble in water. Isoprene forms binary azeotropes with water, methanol, methylamine, acetonitrile, methyl formate, bromoethane, ethyl alcohol, methyl sulfide, acetone, propylene oxide, ethyl formate, isopropyl nitrate, methyla1 (dimethoxymethane), ethyl ether, and / -pentane. Ternary azeotropes form with water—acetone, water—acetonitrile, and methyl formate—ethyl bromide (8). Typical properties of isoprene are Hsted in Table 1. 

Ethyl Bromide. Ethyl bromide [74-96 ] (bromoethane), CH2CH2Br, is a volatile, clear, colorless Hquid of mp, —119.3 C bp, 38.4°C ... 

Bromoethane Ethyl hroniide 197 C HsBr Methanol Methyl alcohol 82 CH4O... 

CH3N02 NITROMETHANE -76.173 2.2736E-01 1.4355E-05 -6.95 72 C2H5BR BROMOETHANE -83.274 1.7808E-01 1.4544E-05 -26.32... 

Bromobenzene Bromochlorodifluoromethane Bromochloromethane 1 -Bromo-2-chloropropane Bromoethane... 

The barrier to rotation about the C—C bond in bromoethane is IS kj/rnol... 

Let s look at a typical polar process—the addition reaction of an alkene, such as ethylene, with hydrogen bromide. When ethylene is treated with HBr at room temperature, bromoethane is produced. Overall, the reaction can be formulated as... 

Because XL.q is relatively large, the reaction proceeds as written and greater than 99.999 99% of the ethylene is converted into bromoethane. For practical purposes, an equilibrium constant greater than about 103 means that the amount of reactant left over will be barely detectable (less than 0.1%). 

HBr to yield bromoethane, which has A5° = -0.332 kJ/(K mol), is an example Table 5.2 describes the thermodynamic terms more fully. 

We call the carbocation, which exists only transiently during the course of the multistep reaction, a reaction intermediate. As soon as the intermediate is formed in the first step by reaction of ethylene with H+, it reacts further with Br in a second step to give the final product, bromoethane. This second step has its own activation energy (AG ), its own transition state, and its own energy change (AG°). We can picture the second transition state as an activated complex between the electrophilic carbocation intermediate and the nucleophilic bromide anion, in which Br- donates a pair of electrons to the positively charged carbon atom as the new C-Br bond starts to form. 

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