Alkyl hahdes

Wurtz - Fittig reaction. The interaction of an aryl halide, alkyl hahde and sodium gives a reasonable yield of an alkyl aryl hydrocarbon, for example ... 

This time the one-carbon discoimection a is all right because the Grignard reagent is Ifom a normal alkyl hahde and does not polymerise. 

Another similar example concerns the alkylation of enamines. This reaction works well with reactive a-halocarbonyl compounds (frames 175ff) but simple alkyl hahdes often react on nitrogen ... 

Strategy Problem 1 The wrong substitution pattern . Making aromatic compounds m-substituted with two o -directing groups is always a problem. What strategies can you suggest An example (TM 412) is the alkyl hahde used in the synthesis of some steroids. 

Nitdles may be prepared by several methods (1). The first nitrile to be prepared was propionitdle, which was obtained in 1834 by distilling barium ethyl sulfate with potassium cyanide. This is a general preparation of nitriles from sulfonate salts and is referred to as the Pelou2e reaction (2). Although not commonly practiced today, dehydration of amides has been widely used to produce nitriles and was the first commercial synthesis of a nitrile. The reaction of alkyl hahdes with sodium cyanide to produce nitriles (eq. 1) also is a general reaction with wide appHcabiUty ... 

The hydroxyl groups on glycols undergo the usual alcohol chemistry giving a wide variety of possible derivatives. Hydroxyls can be converted to aldehydes, alkyl hahdes, amides, amines, a2ides, carboxyUc acids, ethers, mercaptans, nitrate esters, nitriles, nitrite esters, organic esters, peroxides, phosphate esters, and sulfate esters (6,7). 

The direct reaction of other alkyl chlorides, such as butyl chloride, results in unacceptably low overall product yields along with the by-product butene resulting from dehydrochlorination. AH alkyl haHdes having a hydrogen atom in a P- position to the chlorine atom are subject to this complication. 

Alkyl hahdes in the presence of silver oxide react with alkyl malates to yield alkoxy derivatives of succinic acid, eg, 2-ethoxysuccinic acid, H00CCH2CH(0C2H )C00H (12,13). A synthetic approach to produce ethers of malic acid is the reaction of malic esters and sodium alkoxides which affords 2-alkoxysuccinic esters (14). 

The porphyrin ligand can support oxidation states of iron other than II and III. [Fe(I)Por] complexes are obtained by electrochemical or chemical reduction of iron(II) or iron(III) porphyrins. The anionic complexes react with alkyl hahdes to afford alkyl—iron (III) porphyrin complexes. Iron(IV) porphyrins are formally present in the carbene, RR C—Fe(IV)Por p.-carbido, PorFe(IV)—Fe(IV)Por nitrene, RN—Fe(IV)Por and p.-nittido, PorFe(IV)... 

Ketenimines are usually prepared from carboxyHc acid derivatives such as amides and imino chlorides via elimination and from nitriles via alkylation with alkyl haHdes under strong basic conditions (21,64). 

Kinetics are slow and many hours are requited for a 95% conversion of the reactants. In the case of the subject compound, there is evidence that the reaction is autocatalytic but only when approximately 30% conversion to the product has occurred (19). Reaction kinetics are heavily dependent on the species of halogen ia the alkyl haHde and decrease ia the order I >Br >C1. Tetrabutylphosphonium chloride exhibits a high solubiHty ia a variety of solvents, for example, >80% ia water, >70% ia 2-propanol, and >50% ia toluene at 25°C. Its analogues show similar properties. One of the latest appHcations for this phosphonium salt is the manufacture of readily dyeable polyester yams (20,21). 

Alkylation of phosphines by alkyl hahdes exhibits reactivity relative to the base strength, ie, PH is the least reactive and tertiary phosphines the most. This reactivity reflects the difficulty in using alkylation to prepare anything except quaternary phosphonium hahdes. 

Metal phosphides can be employed to direct the action of alkyl hahdes more toward primary and secondary phosphines. 

Ca.ta.lysis, Iridium compounds do not have industrial appHcations as catalysts. However, these compounds have been studied to model fundamental catalytic steps (174), such as substrate binding of unsaturated molecules and dioxygen oxidative addition of hydrogen, alkyl haHdes, and the carbon—hydrogen bond reductive elimination and important metal-centered transformations such as carbonylation, -elimination, CO reduction, and... 

All lation. Alkylating agents such as diaLkyl sulfates and alkyl hahdes react with ahphatic amine oxides to form trialkylalkoxyammonium quaternaries. For example (33), methyl iodide reacts with trimethyl amine oxide to form trimethylmethoxyammonium iodide... 

Method 7. Alkyl haHde amination reaction of ammonia or alkylamine with an alkyl haHde. 

A number of 2eohtic materials have been claimed to cataly2e this reaction and reaction temperatures are on the order of 200—350°C with pressures as high as 18000 kPa (2600 psi) reported. This is a low conversion process and recycle of the unconverted starting materials is necessary to provide an economical process. Amination of ethylene to produce ethylamines cataly2ed by ammonium iodide is reported, but not beheved to be practiced commercially (15,16). Alkyl Halide Amination (Method 7). The oldest technology for pioducing amines is the reaction of ammonia with an alkyl hahde. This... 

Nitriles. Nitriles can be prepared by a number of methods, including ( /) the reaction of alkyl haHdes with alkaH metal cyanides, (2) addition of hydrogen cyanide to a carbon—carbon, carbon—oxygen, or carbon—nitrogen multiple bond, (2) reaction of hydrogen cyanide with a carboxyHc acid over a dehydration catalyst, and (4) ammoxidation of hydrocarbons containing an activated methyl group. For reviews on the preparation of nitriles see references 14 and 15. 

Reaction with Alkyl Halide. The active methylene group of an Al-acylamino-malonic acid ester or Ai-acylamino cyanoacetic acid ester condenses readily with primary alkyl hahdes. 

Hydroxyl Group. Reactions of the phenohc hydroxyl group iaclude the formation of salts, esters, and ethers. The sodium salt of the hydroxyl group is alkylated readily by an alkyl hahde (WiUiamson ether synthesis). Normally, only alkylation of the hydroxyl is observed. However, phenolate ions are ambident nucleophiles and under certain conditions, ring alkylation can also occur. Proper choice of reaction conditions can produce essentially exclusive substitution. Polar solvents favor formation of the ether nonpolar solvents favor ring substitution. 

The esters of sahcyhc acid account for an increasing fraction of the sahcyhc acid produced, about 15% in the 1990s. Typically, the esters are commercially produced by esterification of sahcyhc acid with the appropriate alcohol using a strong mineral acid such as sulfuric as a catalyst. To complete the esterification, the excess alcohol and water are distilled away and recovered. The cmde product is further purified, generally by distillation. For the manufacture of higher esters of sahcyhc acid, transestetification of methyl sahcylate with the appropriate alcohol is the usual route of choice. However, another reaction method uses sodium sahcylate and the corresponding alkyl hahde to form the desired ester. 

The organic chemistry of thiocyanates is notably that of nucleophilic displacement of alkyl haHdes by thiocyanate anion to form alkyl thiocyanates ... 

All lation. In alkylation, the dialkyl sulfates react much faster than do the alkyl haHdes, because the monoalkyl sulfate anion (ROSO ) is more effective as a leaving group than a haHde ion. The high rate is most apparent with small primary alkyl groups, eg, methyl and ethyl. Some leaving groups, such as the fluorinated sulfonate anion, eg, the triflate anion, CF SO, react even faster in ester form (4). Against phenoxide anion, the reaction rate is methyl triflate [333-27-7] dimethyl sulfate methyl toluenesulfonate [23373-38-8] (5). Dialkyl sulfates, as compared to alkyl chlorides, lack chloride ions in their products chloride corrodes and requires the use of a gas instead of a Hquid. The lower sulfates are much less expensive than lower bromides or iodides, and they also alkylate quickly. 

The reactions of these nucleophilic processes are usually S 2 rather than S l. The reaction rate is methyl > ethyl > isopropyl, as with the alkyl hahdes. As the species to be alkylated becomes more nucleophilic, alkylation becomes faster, eg, a sulfur-containing anion alkylates more quickly than a phenohc anion. 

Various vinyl chloride adducts can be formed under acid-catalyzed Friedel-Crafts conditions. Vinyl chloride can add tertiary alkyl haHdes (54). It can... 

AsH, primary and secondary amines, and lower alcohols, BCl, BBr, and BI react to hberate the corresponding hydrogen hahde. Tertiary alcohols and the boron tnhahdes yield the alkyl hahde and boric acid. The boron tnhahdes hydrolyze readily in water or moist air to produce boric acid and hydrogen hahdes. 

The halogen acids also produce alkyl hahdes. 

Examples are given of common operations such as absorption of ammonia to make fertihzers and of carbon dioxide to make soda ash. Also of recoveiy of phosphine from offgases of phosphorous plants recoveiy of HE oxidation, halogenation, and hydrogenation of various organics hydration of olefins to alcohols oxo reaction for higher aldehydes and alcohols ozonolysis of oleic acid absorption of carbon monoxide to make sodium formate alkylation of acetic acid with isobutylene to make teti-h ty acetate, absorption of olefins to make various products HCl and HBr plus higher alcohols to make alkyl hahdes and so on. 

Preparation of Memfield resin-bound nitro acetates, which is a suitable bndding block for the development of combinatorial solid phase synthesis, is repotted. The anion of ethyl nitro acetate is generated in DMF by an electrochemical method using Pt cathode, magnesium rod anode, and tetrabutylairunonium bromide as an electrolyte. Alkylaton of this anion with alkyl hahdes gives mono-alkylated products in 80% yield." ... 

The clidnion derived from methyl d-nitraprapanodte is formed on treatment with LDA, and it is alkylated by alkyl hahdes exclusively at the 2-posidQn fEq 5 6 Eliminadonof HNOj v/ith DBU InTHF furnishes methyl ct-raethylenealkanoate fsee Secdon 7 3, which discusses alkene formadoni "... 

Thus, the direct alkyladon of the anions derived from nitroalkanes v/ith alkyl hahdes has some chfficiddes, and such chfficuldes are partially overcome by the radicM reacdc raetM catMyzed reacdons, as discussed in Secdons 5 4 and 5 5... 

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