Tertiary amines alkylation

A second alkylation may follow converting the secondary amine to a tertiary amine Alkylation need not stop there the tertiary amine may itself be alkylated giving a qua ternary ammonium salt... 

Nearly every substitution of the aromatic ring has been tolerated for the cyclization step using thermal conditions, while acid-promoted conditions limited the functionality utilized. Substituents included halogens, esters, nitriles, nitro, thio-ethers, tertiary amines, alkyl, ethers, acetates, ketals, and amides. Primary and secondary amines are not well tolerated and poor yield resulted in the cyclization containing a free phenol. The Gould-Jacobs reaction has been applied to heterocycles attached and fused to the aniline. 

Alkylation can also be carried out, in certain compounds, at positions a to other heteroatoms, for example, at a position a to the nitrogen of tertiary amines. Alkylation a to the nitrogen of primary or secondary amines is not generally feasible because an NH hydrogen is usually more acidic than a CH hydrogen. a-Lithiation of... 

Sulfur Compounds—Other Significant Sulfur Hexafluoride Technetium Tertiary Alcohols Tertiary Amines (Alkyl, Aryl)... 

LONZA, INC. Tertiary Amines Alkyl Imidazoline Amines ... 

Even this is not all If the alkylation were to continue, the secondary and the tertiary amines would be produced all together in the reaction mixture. The reaction comes to an end only when the tetra-alkylammonrum salt R4N is formed. This salt could be the product if a large excess of alkyl halide RI is used, but other more controlled methods are needed for the synthesis of primary, secondary, and tertiary amines, alkylation of the secondary amine... 

Tertiary Amines. - Alkylation under a variety of conditions continues to be an important route to tertiary amines. Irradiation of secondary amines in alcohols containing a suspension of titanium... 

IS. Tropinone is a tertiary amine. Alkylation of nitrogen can occur from either the Icri" or "right (arrows, below), giving stcreoisomcric products. 

Tertiary amine Alkylating agent Figure 14.6. Cationics from alkylation of tertiary amines... 

If, however, a tertiary amine has two alkyl groups and also an aryl group having the para position unsubstituted, then the action of nitrous acid is to insert the nitroso group directly into this para position. Dimethylaniline, for example, when treated with nitrous acid readily gives p-nitrosodimethyl-... 

Tertiary amines containing one alkyl and two aryl groups, such as mono-I ncthyldiphenyhiniir.e, Cl l3(C, l l.diX , arc rarely encountered and arc unimportant. They usually react with nitrous acid with the insertion of a nitroso group into only one of the two available para positions monomethyl-diphenylamine thus gives monomethyl-mono - pnitroso-diphenylamine. Cl hj(C.ill .)N C l 1 jXO, or V-nicthyl-p-nitrosodiphcnylaniine. 

In the absence of a tertiary amine, the initial reaction is again the formatfon of a trialkyl phosphite and hydrogen chloride. The latter now reacts rapidly with the trialkyl phosphite to give the alkyl chloride and the dialkyl hydrogen... 

The quinaldine is separated from any unreacted aniline and from the alkyl-anilines by treatment with acetic anhydride, basified with sodium carbonate and steam distilled. Only the primary and secondary amines are acetylated the acetylated amines are now much less volatile so that separation from the steam-volatile quinaldine (a tertiary amine) is facile. 

Aliphatic and some aryl-alkyl tertiary amines... 

Alkyl groups attached to aromatic rings are oxidized more readily than the ring in alkaline media. Complete oxidation to benzoic acids usually occurs with nonspecific oxidants such as KMnO, but activated tertiary carbon atoms can be oxidized to the corresponding alcohols (R. Stewart, 1965 D. Arndt, 1975). With mercury(ll) acetate, allyiic and benzylic oxidations are aJso possible. It is most widely used in the mild dehydrogenation of tertiary amines to give, enamines or heteroarenes (M. Shamma, 1970 H. Arzoumanian. 1971 A. Friedrich, 1975). 

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. 

Tertiary amines may be obtained from alkaline alkylation of secondary amines (46), but mixtures are obtained (see Section III.l.B) hence heterocyclization and ammonolysis of 2-halothiazoles are to be preferred. 

Even the tertiary amine competes with ammonia for the alkylating agent The product is a quaternary ammonium salt... 

A method that achieves the same end result as that desired by alkylation of ammonia but which avoids the formation of secondary and tertiary amines as byproducts is the Gabriel synthesis Alkyl halides are converted to primary alkylamines without contam mation by secondary or tertiary amines The key reagent is the potassium salt of phthal imide prepared by the reaction... 

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... 

Reduction of amides (Section 22 9) Lithi um aluminum hydride reduces the car bonyl group of an amide to a methylene group Primary secondary or tertiary amines may be prepared by proper choice of the starting amide R and R may be ei ther alkyl or aryl... 

Alkylation (Section 22 12) Amines act as nucleophiles toward alkyl halides Pri mary amines yield secondary amines secondary amines yield tertiary amines and tertiary amines yield quaternary ammonium salts... 

Tertiary amine (Section 22 1) Amine of the type R3N with any combination of three alkyl or aryl substituents on nitrogen Tertiary carbon (Section 2 13) A carbon that is directly at tached to three other carbons... 

CycHc carbonates are made by treating 1,2-diols with dialkyl carbonates using an alkyl ammonium and tertiary amine catalyst. The combination of propylene glycol and dimethyl carbonate has been reported to result in a 98% yield of propylene carbonate (21). 

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