Tertiary-alkyl primary amines

Tertiary alkyl primary amines can be oxidized to nitro compounds in excellent yields A ith KMn04. This type of nitro compound is not easily prepared in other ways. 

The antioxidant and acid neutralization properties of most fuel stabilizer formulations help to prevent the initial formation of most acids. Compounds such as tertiary-alkyl primary amines, as shown by the example in FIGURE 6-5, are quite effective distillate fuel additives. These oil-soluble amines can be formulated into stabilizer formulations at relatively low concentrations and can provide a significant boost in overall performance of a fuel stabilizer. 

Tertiary alkyl primary amines can be oxidized to nitro compounds in excellent yields with KMn04.39S This type of nitro compound is not easily prepared in other ways. All classes of primary amine (including primary, secondary, and tertiary alkyl as well as aryl) are oxidized to nitro compounds in high yields with dimethyldioxirane.399 Other reagents that oxidize various types of primary amines to nitro compounds are dry ozone,4,111 various peracids,401 including peracetic and peroxytrifluoroacetic acids, f-butyl hydroperoxide in the presence of certain molybdenum and vanadium compounds,402 F7-H20-MeCN,41123 and sodium perborate.403... 

As mentioned above, nitro compounds are obviously of great importance in organic chemistry and aryl nitro compounds are an important source of aniline derivatives (secs. 4.2.C.V, 4.8.D). Both amine oxides and nitrones have been synthetically exploited. Alkyl nitroso derivatives, however, usually cannot be isolated since they decompose in solution, although the aromatic derivatives are more stable in solution and can be used in synthesis (sec. 2.1 l.E). Treatment of a primary amine with excess peroxyacid is a useful preparative route to alkyl nitro compounds.588 Yields are highest for tertiary alkyl primary amines next come secondary, followed by primary alkyl. Peroxyacid oxidation of oximes also provides a route to alkyl nitro compounds.589 This method is convenient for preparing aromatic nitro compounds as in the oxidation of 2,6-dichloroaniline to 2,6-dichloronitrobenzene (441).590 Nitrones are 1,3-dipoles and have been used in 1,3-dipolar cycloaddition reactions (sec. ll.ll.D). 

Primary, secondary, and tertiary aliphatic amines have been cleaved to give aldehydes, ketones, or carboxylic acids with aqueous bromine and with neutral permanganate. The other product of this reaction is the amine with one less alkyl group. In a different type of procedure, primary alkyl primary amines can be converted to ge/n-dihalides, RCH2NH2 —> RCHX2 (X =Br or Cl), by treatment with an alkyl nitrite and the anhydrous copper(I) halide. 

The branching of the polymer is shown schematically in (25). The distribution of amino groups in 25% primary, 50% secondary, and 25% tertiary. The primary amines occur on the outside of the molecule and are easily substituted by acylation and alkylation. 

Alkyl halides or sulfuric or sulfonic esters can be heated with sodium or potassium thiocyanate to give alkyl thiocyanates, " although the attack by the analogous cyanate ion (10-44) gives exclusive V-alkylation. Primary amines can be converted to thiocyanates by the Katritzky pyrylium-pyridinium method (p. 498). ° Tertiary... 

Uranium(VI) is present in solution as the uranyl sulfate anion. The extraction of uranium(VI) by amines occurs in the order of tertiary > secondary > primary amine. The extraction of iron(Ill) occurs in the reverse order, so tertiary amines represent an obvious choice of extractant The tertiary alkyl amine sold as Alamine 336 or Armeen 380 is widely nsed, nsnaUy in conjunction with an alcohol phase modifier (such as isodecanol) to prevent the formation of a third phase and inhibit the formation of emulsions. 

Amines are powerful nucleophiles which react under neutral or slightly basic conditions with several electron-accepting carbon reagents. The reaction of alkyl halides with amines is useful for the preparation of tertiary amines or quaternary ammonium salts. The conversion of primary amines into secondary amines is usually not feasible since the secondary amine tends towards further alkylation. 

Among compounds other than simple alkyl halides a halo ketones and a halo esters have been employed as substrates m the Gabriel synthesis Alkyl p toluenesul fonate esters have also been used Because phthalimide can undergo only a single alkyl ation the formation of secondary and tertiary amines does not occur and the Gabriel synthesis is a valuable procedure for the laboratory preparation of primary amines... 

Ammonia can act as a nucleophile toward primary and some secondary alkyl halides to give primary alkylamines Yields tend to be modest because the primary amine IS itself a nucleophile and undergoes alkylation Alkylation of ammonia can lead to a mixture containing a primary amine a secondary amine a tertiary amine and a quaternary ammonium salt... 

Ritter Reaction (Method 4). A small but important class of amines are manufactured by the Ritter reaction. These are the amines in which the nitrogen atom is adjacent to a tertiary alkyl group. In the Ritter reaction a substituted olefin such as isobutylene reacts with hydrogen cyanide under acidic conditions (12). The resulting formamide is then hydroly2ed to the parent primary amine. Typically sulfuric acid is used in this transformation of an olefin to an amine. Stoichiometric quantities of sulfate salts are produced along with the desired amine. 

Alkylation (Section 22.12) Amines act as nucleophiles toward alkyl halides. Primary amines yield secondary amines, secondary amines yield tertiary amines, and tertiary amines yield quaternary ammonium salts. 

The reaction of potassium phthalimide 1 with an alkyl halide 2 leads to formation of a N-alkyl phthalimide 3/ which can be cleaved hydrolytically or by reaction with hydrazine (Ing-Manske variant) to yield a primary amine 5. This route owes its importance as a synthetic method to the fact that primary amines are prepared selectively, not contaminated with secondary or tertiary amines. 

Unsymmetrically substituted secondary and tertiary amines are named as iV-substituted primary amines. The largest alkyl group is chosen as the parent name, and the other alkyl groups are N-substituents on the parent (jY because they re attached to nitrogen). 

Ammonia and other amines are good nucleophiles in SN2 reactions. As a result, the simplest method of alkylamine synthesis is by Sn2 alkylation of ammonia or an alkylamine with an alky) halide. If ammonia is used, a primary amine results if a primary amine is used, a secondary amine results and so on. Even tertiary amines react rapidly with alkyl halides to yield quaternary ammonium salts, R4N+ X-... 

The reaction of diazo compounds with amines is similar to 10-15. The acidity of amines is not great enough for the reaction to proceed without a catalyst, but BF3, which converts the amine to the F3B-NHR2 complex, enables the reaction to take place. Cuprous cyanide can also be used as a catalyst. The most common substrate is diazomethane, in which case this is a method for the methylation of amines. Ammonia has been used as the amine but, as in the case of 10-44, mixtures of primary, secondary, and tertiary amines are obtained. Primary aliphatic amines give mixtures of secondary and tertiary amines. Secondary amines give successful alkylation. Primary aromatic amines also give the reaction, but diaryl or arylalkyl-amines react very poorly. 

The treatment of sulfonyl chlorides with ammonia or amines is the usual way of preparing sulfonamides. Primary amines give N-alkyl sulfonamides, and secondary amines give N,N-dialkyl sulfonamides. The reaction is the basis of the Hinsberg test for distinguishing between primary, secondary, and tertiary amines. N-Alkyl sulfonamides, having an acidic hydrogen, are soluble in alkali, while N,N-dialkyl sulfon-... 

The alkyl halide (ethyl bromide in the above equation) can react further with the primary amine produced to give a secondary amine and with that to form a tertiary amine and finally a quaternary ammonium salt. Quaternary ammonium hydroxides are very strong bases like sodium hydroxide. Tetramethylammonium hydroxide is a very important chemical used in the manufacture of semiconductors and other electronic industry products. 

The Hofmann elimination is useful synthetically for preparing alkenes since it gives the least substituted alkene. The reaction involves thermal elimination of a tertiary amine from a quaternary ammonium hydroxide these are often formed by alkylation of a primary amine with methyl iodide followed by reaction with silver oxide. The mechanism of the elimination is shown in Scheme 1.13 in this synthesis of 1-methyl-1-... 

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