Bromoethane with ethanol

Write a balanced equation for the reaction of bromoethane with ethanolic sodium hydroxide. 

Let us consider one other reaction of ethanol. If ethanol is heated with aqueous HBr, we find that a volatile compound is formed. This compound is only slightly soluble in water and it contains bromine its molecular formula is found by analysis and molecular weight determination to be C2HsBr (ethyl bromide, or bromoethane). With the aid of the bonding rules, we can see that there is only one possible structure for this compound. This result is verified by the fact that only one isomer of C2H6Br has ever been discovered. 

If you decided to investigate the reaction between ethanol and each of these three reagents in turn, you would find that only hydrogen bromide reacts with ethanol to give bromoethane... 

J Does the fact that bromoethane undergoes substitution faster with the ethoxide anion than with ethanol fit with the order of reactivity of nucleophiles ... 

Bromoethane reacts with ethanol (or with sodium ethoxide) by the Sn2 mechanism. Because ethanol is a poor nucleophile this reaction is very slow. On the other hand. 

An elimination reaction is often in competition with a substitution reaction and the predominant product will depend on the reaction conditions. The reaction of bromoethane with sodium hydroxide could yield either ethene (by elimination of HBr) or ethanol (by substitution of the Br with OH). The former product predominates if the reaction is carried out in an alcoholic solution and the latter if the solution is aqueous. 

Also obtained by reaction of bromoethane with 2-hydroxybenzophenone in the presence of sodium ethoxide in ethanol [1478],... 

Ethylamine is prepared either by reducing ethanenitrile, e.g. with hydrogen gas using a nickel catalyst, or by treating bromoethane with an excess of hot, ethanolic ammonia. 

A 100 MHz NMR spectrum of a mixture of ethanol (C2H6O) 5 18.3 (CH3), 5 57.8 (CH2) and bromoethane (C2HsBr) 5 19.5 (CH3) and 6 27.9 (CH2) in CDCI3 solution is given below. The spectrum was recorded with a long relaxation delay (300 seconds) between acquisitions and with the NOE suppressed. Estimate the relative proportions (mole %) of the 2 components from the peak intensities in the spectrum. 

A(A -Bis(3-aminopiopyl)ethylenediamme is prepared by the method of E. K. Barefield. Six moles of 1,3-propanediamine is dissolved in 1.4 L of absolute ethanol and the solution is cooled to 5° in an ice bath. To this solution is added 0.75 mole of 1,2-di-bromoethane from a dropping funnel with vigorous stirring. After the addition is complete, the reaction is heated to reflux temperature for I A hours.. Potassium hydroxide, 150 g, is added and the mixture is refluxed for a further 1 hour. The reaction mixture is cooled to room temperature and filtered to remove the solids. The filtrate is evaporated to a sludge on a rotary evaporator and the semisolid is extracted several times with diethyl ether. The ether solution is evaporated until a viscous liquid remains. The liquid is distilled in vacuo (b.p. 138-148°/2 ton) and stored over potassium hydroxide pellets in a bottle protected from light. The yield is 64 g. 

In most of the reactions that we have described here, the substrate has been modified by reaction at the functional group, and the hydrocarbon framework has remained unchanged. In Example 2.1, ethanol reacted with hydrogen bromide at the site where the hydroxyl group is attached to produce bromoethane... 

The mechanism for this reaction begins with formation of an oxonium cation. Then, an Sn2 reaction with a bromide ion acting as the nucleophile produces ethanol and bromoethane. Excess HBr reacts with the ethanol produced to form the second molar equivalent of bromoethane. 

Ester enolates undergo alkylation reactions. When ethyl 3-methylpentanoate (110) reacts with sodium ethoxide in ethanol and then with bromoethane, the product is 111. Alkylation of malonate derivatives leads to an interesting sequence of reactions that are useful in synthesis. The reaction of diethyl malonate (90) and NaOEt in ethanol, followed by reaction with benzyl bromide, gives 112. In a second reaction, 112 reacts with NaOEt in ethanol and then with iodomethane to give 113. Saponification of 113 (see Chapter 20, Section 20.2) gives the dicarboxylic acid, 114, and heating leads to decarboxylation (Section 22.8) and formation of acid 115. This overall sequence converted malonic acid via the diester to a substituted carboxylic acid, and it is known as the malonic ester synthesis. 

For example, in protic solvents such as water (H2O) and water-ethanol (ethyl alcohol, CH3CH2OH) mixtures, large ions that are more polarizable and may more readily provide an electron pair for the displacement process are also more poorly solvated than small ions. Thus, with the same substrate (e.g., bromoethane [ethyl bromide, CH3CH2Br]) as shown in Table 7.5, nucleophilicity increases with increasing atomic number in any one group (column) of the periodic table (i.e., T > Br > Cl > F") in such solvents. In this vein, it should be noted that this means that nucleophilicity does not parallel basicity since, as noted earlier, the order of basicity in aqueous solution is Cl > Br > F. 

Nucleophilic substitution reactions are important in organic synthesis because the halogen atom on halogenoalkanes can be replaced by other functional groups. The reaction with potassium cyanide is a good illustration of this. The cyanide ion reacts to form a nitrile. For example, bromoethane reacts by an Sj42 mechanism with a solution of potassium cyanide in ethanol to form propanenitrile ... 

In these reactions, the halogen replaces the hydroxyl group on the alcohol. For example, ethanol reacts with hydrobromic acid to form bromoethane and water ... 

Next, let s consider a reaction in which bromoethane reacts with water to give ethanol. 

In Chapter 16 (page 218) you learnt how bromoethane undergoes nucleophilic substitution with ammonia to form a mixture of amines. In order to prepare ethylamine (while avoiding the formation of secondary and tertiary amines and ammonium salts) we use excess hot ethanolic ammonia ... 

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