Ethyl iodide preparation

Preparation by reaction of 2,3-dimethoxy-5-methylbenzoyl chloride with zinc ethyl iodide (prepared according to [7309] in toluene atr.t.for2h(70%) [7110]). 

Since aliphatic hydrocarbons (unlike aromatic hydrocarbons, p. 155) can be directly nitrated only under very special conditions, indirect methods are usually employed for the preparation of compounds such as nitroethane, CjHsNO. When ethyl iodide is heated with silver nitrite, two isomeric compounds are formed, and can be easily separated by fractional distillation. The first is the true ester, ethyl nitrite, C,HiONO, of b.p. 17° its identity is shown by the action of hot sodium hydroxide solution, which hydrolyses it, giving ethanol and... 

Three reactants. Ethyl iodide may be prepared by the interaction between iodine, ethyl alcohol and red phosphorus. The quantities employed and the yield obtained in a particular experiment are given below the equation. 

Add 4 0 g. (4 0 ml.) of pure anihne dropwise to a cold solution of ethyl magnesium bromide (or iodide) prepared from 1 Og. of magnesium, 5 0 g. (3-5 ml.) of ethyl bromide (or the equivalent quantity of ethyl iodide), and 30 ml. of pure, sodium-dried ether. When the vigorous evolution of ethane has ceased, introduce 0 02 mol of the ester in 10 ml. of anhydrous ether, and warm the mixture on a water bath for 10 minutes cool. Add dilute hydrochloric acid to dissolve the magnesium compounds and excess of aniline. Separate the ethereal layer, dry it with anhydrous magnesium sulphate and evaporate the ether. Recrystallise the residual anihde, which is obtained in almost quantitative yield, from dilute alcohol or other suitable solvent. 

The ethiodide is prepared similarly, using ethyl iodide. 

Keep a coil of copper wire (prepared by winding copper wire round a glass tube) or a little silver powder in the bottle, which should be of brown or amber glass the methyl iodide will remain colourless indefinitely. Ethyl iodide may sometimes give more satis factory results. 

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. 

Note 1. Prepared by adding CS2 to CH MgBr in THE at 0°C, preferably in the presence of a small amount of CuBr (2 mol %), and subsequently alkylating with ethyl iodide . 

They are used principally as intermediates for cyanine dyes that serve in photography (5, 6. 35. 36. 50-52). 3-Ethyl-2,4-dimethylselenazolium iodide (m.p. 157-8 C) was prepared as colorless crystals in 87% yield by Brooker et al. (6) by heating 2,4-dimethyls el en azole with an excess of ethyl iodide for 48 hr. 

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. 

Various alkylating agents are used for the preparation of pyridazinyl alkyl sulfides. Methyl and ethyl iodides, dimethyl and diethyl sulfate, a-halo acids and esters, /3-halo acids and their derivatives, a-halo ketones, benzyl halides and substituted benzyl halides and other alkyl and heteroarylmethyl halides are most commonly used for this purpose. Another method is the addition of pyridazinethiones and pyridazinethiols to unsaturated compounds, such as 2,3(4//)-dihydropyran or 2,3(4//)-dihydrothiopyran, and to compounds with activated double bonds, such as acrylonitrile, acrylates and quinones. 

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. ... 

Tetraethyltin has been prepared from tin-sodium alloy and ethyl iodide, from tin-sodium-zinc alloy and ethyl bromide, and from tin tetrachloride and ethylmagnesium bromide. The method described is essentially that of Pfeiffer and Schnur-mann. ... 

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. ... 

The same method may be used without modification for preparing phenyl ethyl carbinol using a corresponding quantity of ethyl iodide. See Appendix, p. 307. 

Ethylmalonic Acid.—Like acetoacetic ester (see p. 83), diethylmalonate contains the gioup CO.CHj.CO. By the action of sodium or sodium alroholate, the hydrogen atoms of the methylene group are successively replaceable by sodium. The sodium atoms are in turn replaceable by alkyl or acyl groups. Thus, in the present preparation, ethyl malonic ester is obtained by the action of ethyl iodide on the monosodium compound. If this substance be treated with a second molecule of sodium alcoholate and a second molecule of alkyl iodide, a second radical would be in roduced, and a compound formed of the general formula... 

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 ... 

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). 

The cyclization products can be ethylated using ethyl iodide with K2CO3 in DMF to give in the case of thiazolo[4,5-g]- or [4,5-/i]quinolones a mixture of O- and N-ethylated products, whereas in the case of thiazolo[5,4-g]- or -[5,4-/i] quinolones only A-ethyl products arise. Products of 0-ethylation were prepared by... 

Because of the basic nitrogen atom, alkyl-selenazoles form quaternary salts. 2,4-Dimethyl-3-ethylselenazolium iodide (mp 157-158 0) was prepared by Brooker et al in 87% yield as colorless crystals by heating of 2,4-dimethylselenazole in excess ethyl iodide for 2 days. By reaction with the corresponding quaternary salts, the following cyanine dyes (8) were prepared" l 3-diethyl-4-methylselenazolo-2 -... 

One of the earliest preparations of this ring system starts with displacement of the hydroxyl of benzaldehyde cyanohydrin (125) by urea. Treatment of the product (126) with hydrochloric acid leads to addition of the remaining urea nitrogen to the nitrile. There is thus obtained, after hydrolysis of the imine (127), the hydantoin (128). Alkylation by means of ethyl iodide affords ethotoin (129)... 

The ethyl ether of hydroquinone, para oxyphenetol, CgHj(,02, is found to a small extent in oil of star aniseed. It can also be prepared artificially by heating para-diazophenetol sulphate with dilute sulphuric acid, or by boiling hydroquinone with ethyl iodide and potassium hydroxide under a reflux condenser. Its constitution is—... 

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