Ethyl iodide, reaction

The secondary a- and perdeutero-deuterium KIEs E2 S 2 ratios reaction efficiencies transition-state looseness parameters and the relative basicities of the nucleophiles in the gas-phase reactions between methyl, ethyl, i-propyl, and f-butyl iodides and SH , Cr, and CN have been used to show that (i) the ethyl and i-propyl iodides react mainly by an Sf 2 mechanism, while the i-butyl iodide reacts by an E2 mechanism, (ii) that the E2 barrier is more sensitive to basicity of the nucleophile than the 5 2 barrier, and (iii) that stronger bases promote more 2 elimination. The KIEs in the ethyl iodide reactions indicate that the transition state becomes looser as the nucleophile changes from Cl to CN to SH. Larger (more normal) deuterium KIEs and looser S 2 transition states are found when more alkyl groups are added to the C of the substrate. 

In the reaction described below triethyl phosphite (p. 308) is heated with ethyl iodide to give diethyl ethylphosphonate. Although theoretically a very small amount of ethyl iodide would suffice, it is advantageous to use more than the minimum amount so as to reduce the temperature of the boiling reaction-mixture. 

The reaction with ethyl iodide is less rapid and it is necessary to warm the mixture gently until cloudy. On cooling, crystals of the ethiodide are formed, and after recrystallisation from methylated spirit have m.p. 84 . 

From the equation representing the chemical reaction involved, it is evident that 330 g. of silver maleate will theoretically react with 312 g. of ethyl iodide in ethereal solution to produce 172 g. of ethyl maleate. It follows, therefore, that 33 g. (0 1 mol) of silver maleate will react with 31-2 g. (0 2 mol) of ethyl iodide to give a theoretical yield of 17 2 g. (0-1 mol) of ethyl maleate. In practice, the actual yield found for these quantities is of the order of 16 0 g. the percentage yield is therefore (16 0/17-2) X 100 = 93 per cent. 

Place 32 g. of potassium ethyl xanthate (Section 111,166) and 50 ml. of absolute ethyl alcohol in a 500 ml. round-bottomed flask provided with a double surface condenser. Add 32 g. (16-5 ml.) of ethyl iodide. No reaction appears to take place in the cold. Heat on a water bath for 3 hours a reaction sets in within 15 minutes and the yellow reaction mixture becomes white owing to the separation of potassium iodide. Add about 150 ml. of water, separate the lower layer, and wash it with water. Dry it with anhydrous calcium chloride or anhydrous calcium sulphate and distil from a 50 ml. Claisen flask. Collect the ethyl S-ethyl xanthate at 196-198°. The yield is 23 g. 

Place 1 55 g. of clean sodium in a 250 ml. round-bottomed flask equipped with a reflux condenser. Add 40 ml. of absolute alcohol (or rectified spirit). If all the sodium has not disappeared after the vigorous reaction has subsided, warm the flask on a water bath until solution is complete. Cool the mixture and add 10 g. of p-acetylaminophenol. Introduce 15 g. (8 ml.) of ethyl iodide slowly through the condenser and reflux the mixture for 45-60 minutes. Pour 100 ml. of water through the condenser at such a rate that the crystalline product does not separate if crystals do separate, reflux the mixture until they dissolve. Then cool the flask in an ice bath collect the crude phenacetin with suction and wash with a little cold water. Dissolve the crude product in 80 ml. of rectified spirit if the solution is coloured, add 2 g. of decolourising carbon and filter. Treat the clear solution with 125 ml. of hot water and allow to cool. Collect the pure phenacetin at the pump and dry in the air. The yield is 9-5 g., m.p. 137°. 

Ethyl phenylethylmalonate. In a dry 500 ml. round-bottomed flask, fitted with a reflux condenser and guard tube, prepare a solution of sodium ethoxide from 7 0 g. of clean sodium and 150 ml. of super dry ethyl alcohol in the usual manner add 1 5 ml. of pure ethyl acetate (dried over anhydrous calcium sulphate) to the solution at 60° and maintain this temperature for 30 minutes. Meanwhile equip a 1 litre threenecked flask with a dropping funnel, a mercury-sealed mechanical stirrer and a double surface reflux condenser the apparatus must be perfectly dry and guard tubes should be inserted in the funnel and condenser respectively. Place a mixture of 74 g. of ethyl phenylmalonate and 60 g. of ethyl iodide in the flask. Heat the apparatus in a bath at 80° and add the sodium ethoxide solution, with stirring, at such a rate that a drop of the reaction mixture when mixed with a drop of phenolphthalein indieator is never more than faintly pink. The addition occupies 2-2 -5 hoius continue the stirring for a fiuther 1 hour at 80°. Allow the flask to cool, equip it for distillation under reduced pressure (water pump) and distil off the alcohol. Add 100 ml. of water to the residue in the flask and extract the ester with three 100 ml. portions of benzene. Dry the combined extracts with anhydrous magnesium sulphate, distil off the benzene at atmospheric pressure and the residue under diminished pressure. C ollect the ethyl phenylethylmalonate at 159-160°/8 mm. The yield is 72 g. 

Strike couldn t find any decent nitroethane synths except for a couple of Chemical Abstract articles. One suggestion is to treat 1.5 moles of Na2C02 with 1 mole of sodium ethylsulfite and 0.0645 moles of K2CO3 at 125-130°C. Another route would be to use silver nitrate and ethyl iodide [8 p119]. This type of reaction has been used to nitrate other paraffins and would probably work. 

Reaction of ethyl iodide with triethylamine [(CH3CH2)3N ] yields a crystalline compound CgH2oNI in high yield This compound is soluble in polar solvents such as water but insoluble in nonpolar ones such as diethyl ether It does not melt below about 200°C Suggest a reasonable structure for this product... 

At 225—275°C, bromination of the vapor yields bromochloromethanes CCl Br, CCl2Br2, and CClBr. Chloroform reacts with aluminum bromide to form bromoform, CHBr. Chloroform cannot be direcdy fluorinated with elementary flourine fluoroform, CHF, is produced from chloroform by reaction with hydrogen fluoride in the presence of a metallic fluoride catalyst (8). It is also a coproduct of monochlorodifluoromethane from the HF—CHCl reaction over antimony chlorofluoride. Iodine gives a characteristic purple solution in chloroform but does not react even at the boiling point. Iodoform, CHI, may be produced from chloroform by reaction with ethyl iodide in the presence of aluminum chloride however, this is not the route normally used for its preparation. 

N,N -Diethylbenzidine has been prepared by heating ethyl iodide, benzidine, and ethanol in a pressure tube at water-bath temperature, and by the reaction of diethylzinc on benzene-diazonium chloride. The method described here is a modification of that of Shah, Tilak, and Venkataraman. ... 

Ethoxy-2-cyclohexenone has been prepared by reaction of the silver salt of dihydroresorcinol with ethyl iodide and by the reaction of dihydroresorcinol with ethyl orthoformate, ethanol and sulfuric acid." The acid-catalyzed reaction of dihydroresorcinol with ethanol in benzene solution utilized in this preparation is patterned after the procedure of Frank and Hall. ... 

Table 8-S. Kinetic Data on the Menschutkin Reaction of Triethylamine and Ethyl Iodide at 25°C...

Table 8-10 gives pertinent data for the Menschutkin reaction of triethylamine with ethyl iodide. These reactant molecules are volatile, so their transfer free energies were determined by a gas chromatographic variation of the vapor pressure method. For this reaction Eq. (8-57) is written... 

Figure 8-6. Ploi according to Fig. 8-5 of transfer free energies of the transition state (ordinate) and reactant state (abscissa) for the Menschutkin reaction of triethylamine and ethyl iodide. The reference solvent is N, Af-dimethylformamide (No. 27). Data are from Table 8-10, where the solvents are identified by number. Closed circles are polychlorinated solvents.

With enamines of cyclic ketones direct C alkylation occurs with allyl and propargyl as well as alkyl halides. The reaction is again sensitive to the polarity of the solvent (29). The pyrrolidine enamine of cyclohexanone on reaction with ethyl iodide in dioxane gave 25% of 2-ethylcyclohexanone on hydrolysis, while in chloroform the yield was increased to 32%. 

Consider the reaction of ethyl propyl ether with HI. Write the two different possible product combinations. Compare e energies of the two products 1-propanol and ethyl iodide-, ethanol and 1-propyl iodide). Which is the lower-energy combination Is the energy difference significant (>.002 au or 1 kcal/mol) Based on thermochemistry alone, is this reaction Likely to be selective Explain. 

Electrostatic interactions can guide alkylation under certain conditions. Examine the electrostatic potential map of the potassium enolate of ethyl acetoacetate. Is carbon or oxygen more electron rich Are electrostatic interactions likely to favor addition of oxygen or carbon Examine atomic charges and electrostatic potential maps for diethylsulfate, ethyl chloride, ethyl bromide and ethyl iodide, pay attention to the backside of the electrophilic carbon. Order the systems from most to least electron poor. Which reaction is most likely to be guided by electrostatics Least likely Can the experimental results be fully explained on this basis ... 

Angier and Marsico followed the course of alkylation first. The 7-dimethylamino-5-methylmercapto derivative reacted with dimethyl sulfate in an alkaline medium to yield a mixture of the 2- and 3-methyl derivatives. The reaction of the 7-diraethylamino derivative with ethyl iodide in an alkaline medium led to a mixture of all three possible monoethyl derivatives. The position of the alkyl group in all these substances was defined by comparing the UV spectra with derivatives prepared by a straightforward synthesis. After reacting the mercuric salts with tri-0-benzoylribofuranosyl chloride, they demonstrated the ribose residue to be bound in position 2. The same structure was shown to be valid for the derivative prepared by Andrews and Barber. ... 

Quaternary salt formation in 4-quinazoline 3-oxide and its 4-amino and 4-methyl derivatives has been studied by Adachi. These N-oxides, prepared by reaction of the simple quinazoline with hydroxylamine, react with ethyl iodide at N-1, although only in the case of the 4-amino derivative could the ethiodide be purified. The salts are degraded by alkali yielding derivatives of ethylaniline [Eq. (4)]. 

Ethyl iodide and 5-amino-2-methyl-l,3,4-thiadiazole react at 110° to give the N-3 salt (78 R = Me, R = NH2, R" = Et), as shown by the presence of the very reactive methyl group this salt is also used to prepare cyanine dyes. The slow quatemization at the ring-nitrogen atom furthest from the amino group is consistent with the reactions observed in other ring systems. As would be e pected, 5-alkylthio-2-methyl-l,3,4-thiadiazoles form salts at the N-3 (78 R = Me, R - S-alkyl).i ... 

R = Et) gives the same salt as is obtained from the interaction of 166 (R = Me) and ethyl iodide. The structure of the salt must therefore be 167, the process being a typical indole-type reaction. 

That alkylation of the anhydro-bases takes place at the indole nitrogen atom in the jS-carboline series was established conclusively by the identity of the product (429), prepared by treatment of pyr-N-ethyl-jS-carboline anhydro-base (428) with ethyl iodide, with 2,9-diethyl-jS-carbolinium iodide (429) obtained from the reaction of imi-A-ethyl-jS-carboline (430) with ethyl iodide (see Section IV, A, 2). 

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