Amines, secondary

Pnmary amine Secondary amine Tertiary amine... 

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... 

Ethoxylation and Propoxylation. Ethylene oxide [75-21-8] or propylene oxide [75-56-9] add readily to primary fatty amines to form bis(2-hydroxyethyl) or bis(2-hydroxypropyl) tertiary amines secondary amines also react with ethylene or propylene oxide to form 2-hydroxyalkyl tertiary amines (1,3,7,33—36). The initial addition is completed at approximately 170°C. Additional ethylene or propylene oxide can be added by using a basic catalyst, usually sodium or potassium hydroxide. 

H-Bond Acceptor-Donor (HBAD) Phenols Aromatic acids Aromatic amines Alpha H nitriles Iniines Monocarboj hc acids Other monoacids Peracids Alpha H nitros Azines Primary amines Secondary amines n-alcohols Other alcohols Ether alcohols... 

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. 

Amides can also be alkylated with diazo compounds, as in 10-49. Salts of sulfonamides (ArS02NH ) can be used to attack alkyl halides to prepare N-alkyl sulfonamides (ArS02NHR) that can be further alkylated to ArS02NRR. Hydrolysis of the latter is a good method for the preparation of secondary amines. Secondary amines can also be made by crown ether assisted alkylation of F3CCONHR (R = alkyl or aryl) and hydrolysis of the resulting F3CCONRR. ... 

Since the order of increasing CL intensity for alkyl amines reacted with Ru(bpy)32+ is tertiary amines > secondary amines > primary amines, pharmaceutical compounds bearing a tertiary amine function (e.g., antihistamine drugs [99], anticholinergic drugs [100], erythromycin [101], and its derivatives [102]) have been sensitively determined after HPLC separation (Table 3). The method was applied to the detection of d- and L-tryptophan (Trp) after separation by a ligand-exchange HPLC [103], The detection limits for d- and L-Trp were both 0.2 pmol per injection. Oxalate in urine and blood plasma samples has also been determined by a reversed-phase ion-pair HPLC (Fig. 18) [104], Direct addition of... 

N-Dealkylation reactions are not restricted to tertiary amines. Secondary amines as well as primary amines can also be dealkylated although both types are less favored than tertiary amines. In the case of primary amines, the lone pair of electrons of the amino group can interact and complex with the Fe3+ of heme. Thus primary amines tend to be inhibitors of P450 activation and for that reason are generally poor substrates. Secondary amines have metabolic properties intermediary between those of tertiary amines and primary amines. They are less-effective inhibitors because of increased steric hindrance to complex formation but are also better substrates because they are less-effective inhibitors and thereby increase the effective concentration of enzyme. 

It is well known that alkyl substitution changes the basicity of amines. However, solvation effects lead to an anomalous order of basicities in solution (NH3 tertiary amine < primary amine < secondary amine). From gas-phase proton affinity data the intrinsic effects of alkyl substituents can be evaluated and a quite regular order (NH3 < primary amine < secondary amine < tertiary amine) is obtained91. 

Carboxylic acid, aldehyde, ketone, ether, alcohol, ester, ester-R (the chain attached to the oxygen atom being a generic substituent), anhydride, acetal, amide, epoxide, acid halyde, primary amine, primary imine, cyano, secondary amine, secondary imine, tertiary amine, nitro derivative, metal-1, metal-2, carbene, halo derivative. 

Amines Secondary amine R2NH H / R —N R amino- -amine HsC CHg N 1 H Dimethyiamine... 

Reductive alkylation of ammonia should give primary amines, reductive alkylation of primary amines secondary amines, and reductive alkylation of secondary amines tertiary amines. In reality, secondary and even tertiary amines are almost always present to varying extents since the primary amines formed in the reaction of the carbonyl compounds with ammonia react with the carbonyl compounds to give secondary amines, and the secondary amines similarly afford tertiary amines according to Scheme 128. In addition, secondary amines may be formed, especially at higher temperatures, by additional reactions shown in Scheme 129. Depending on the ratios of the carbonyl compounds to ammonia or amines, different classes of amines predominate. 

Unwanted degradation and oxidation processes can be avoided or at least suppressed for some time either by structural modiflcation of the polymer or by special additives. In practice, the addition of so-called antioxidants is particularly effective. Chemical substances that slow down oxidations and the following aging phenomena serve for this purpose. Antioxidants are sufficiently effective even in concentrations below 1 wt% and are added as early as possible to the polymer to be protected, e.g., already during the drying of powdery polymeric materials or during the preparation of granulates. Some of the most important so-called primary antioxidants are sterically hindered phenols and secondary aromatic amines secondary antioxidants are thioethers as well as phosphites and phosphonites. 

The ability of [18]crown-6 derivatives to complex primary alkylammonium ions has been elegantly exploited in the protection of primary amines (80CC300). In the presence of primary amines, secondary amines can be acylated selectively by adding [18]crown-6 and a proton source. This strategy has obvious advantages over normal amine protecting groups which require a deprotection step. 

Selection of the reagents was based on the Pfizer internal compound collection which allowed speedy acquisition of any selected compound. A set of primary amines, secondary amines, and carboxylic acids which were not commercially available were chosen for consideration. These acids and amines were designed by medicinal chemists via a Pfizer internal screening file enrichment effort to be novel and diverse, and more importantly, were not part of any existing Pfizer fragment collection. The MW... 

Primary amines have been prepared from many aldehydes with at least five carbons and from many ketones by treatment with ammonia and a reducing agent. Smaller aldehydes are usually too reactive to permit isolation of the primary amine. Secondary amines have... 

AMINES. An amine is a derivative of NH3 in which there is a replacement for one or more of the H atoms of Nil, by an alkyl group, such as -CH3 (methyl) or -C2H5 (ethyl) or by an aryl group, such as (>, H (phenyl) or i ll (naphthyl). Mixed amines contain at least one alkyl and one aryl group as exemplified by methylphenylamine CH3 Nnij O.H . When one, two, and three H atoms arc thus replaced, the resulting amines ate known as primary, secondary, and tertiary, icspectively. Thus, methylamine, CH3NH2, is a primary amine dimethylamine, iCHj) NH, is a secondary amine and trimethylamine. (CHs N. is a tertiary amine. Secondary amines sometimes are called imines tertiary amines, nitriles. 

Reaction CXXXII. Action of Aliphatic Halogen Compounds on Aliphatic or Aromatic Primary Amines.—Secondary, tertiary and quaternary compounds may be formed. 

The first such study involved the deprotonation of the cationic rhenium Fischer carbene complexes 48H+-X by primary aliphatic amines, secondary... 

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