Primary amines, 31 Table

Observed stoichiometries for the compounds with the primary amines (Table 9) are for integral values of n in (MnX2-A ) of 6, 4, 2 and 1 (the two non-integral values, assigned to nitrates, need further confirmation). 

Other ammonia derivatives containing an —NHj group react with carbonyl compounds similarly to primary amines. Table 9.1 lists some specific examples. Notice that in each of these reactions, the two hydrogens attached to nitrogen and the oxygen of the carbonyl group are eliminated as water. 

In contrast, both ketones and aldehydes, the former more slowly than the latter, generally react with aromatic and aliphatic primary amines (Table 9.4,2a) to produce the corresponding hemiaminals (carbinolamines), which are usually not isolated as they readily lose water to produce imines (sometimes called Schiff s bases). Thus,... 

While the early part of the acid-catalyzed path to form an imine (i.e., production of a protonated hemiaminal) appears the same for secondary amines (Table 9.4, 2b) and primary amines (Table 9.4,2a), the absence of a proton on nitrogen denies that intermediate the ability to lose water as shown in Scheme 9.65. Therefore, if there is a proton on the adjacent carbon, water is lost with the formation of a nitrogenbearing, carbon-carbon double bond species called an enamine (Scheme 9.66). Although it wiU be discussed later in this chapter when addition to the carbon a alpha) to the carbonyl (C=0) is separately considered it is worthwhile noting here... 

Lengthening of the alkyl chain makes only relatively slight differences to the piiTa values of primary amines (Table 2). After a very small increase in ethylamine they remain almost constant up to n-decyl-amine, after which there seems to be a slight decrease. Chain branching also produces very little effect. Amongst secondary amines (Table 3) there is evidence of the values rising to a maximum at di-n-butyl-amine, after which they assume an almost constant value. 

Primary amines or amides have well-localized NH2 symmetric (vi) and antisymmetric (V3) stretching vibrations, giving rise to vi + V3 combination tones as in the case of water, which are allowed under C2 symmetry and even more so in molecules that have no symmetry at all. The anharmonicity constant of primary amines (Table 2.2) is generally divided about half and half between the antisymmetric and symmetric modes, as compared with the anharmonicity constants of secondary amines (Table 2.1). The anharmonic coupling constant X13, amounted from -91 to -157 cm for substituted anilines (34), whereas it is —155 for water (33). 

A number of compounds of the general type H2NZ react with aldehydes and ketones m a manner analogous to that of primary amines The carbonyl group (C=0) IS converted to C=NZ and a molecule of water is formed Table 17 4 presents exam pies of some of these reactions The mechanism by which each proceeds is similar to the nucleophilic addition-elimination mechanism described for the reaction of primary amines with aldehydes and ketones... 

Although this reaction is useful for preparing a ammo acids (Table 22 3 fifth entry) it IS not a general method for the synthesis of amines Its major limitation is that the expected primary amine product is itself a nucleophile and competes with ammonia for the alkyl halide... 

Nitrosation (Section 22 15) Nitrosation of amines occurs when sodium nitrite is added to a solution containing an amine and an acid Primary amines y e d alkyl diazonium salts Alkyl diazonium salts are very unstable and yield carbo cation derived products Aryl diazonium salts are exceedingly useful synthetic in termediates Their reactions are de scribed in Table 22 7... 

A number of other N-substituted 2-pyrroHdinones have been offered commercially or promoted as developmental products. These materials offer different and sometimes unique solvency properties. AH are prepared by reaction of butyrolactone with suitable primary amines. Principal examples are Hsted in Table 4. 

A novel fluorination technique features reaction of primary amines with 2,4,6-triphenyIpyrlium fluonde to give 2,4,6-tnphenylpyndinium fluoride, which on heating forms primary fluondes [I, 2] (equation 1 and Table 1)... 

Table 1. Primary Monofluorides and a,oi-Difluorides from 2,4,6-Triphenylpyridinium Fluoride and Primary Amines and Diamines [1,2]...

It has been shown (140) that enamines react as well, if not better, under the conditions of the Leuckart-Wallach reaction to give amines than do ketones in the presence of ammonia, primary amines, or secondary amines. This implies that in the Leuckart-Wallach reaction the pathway may be through the enamine and, of course, the iminium salt. The Leuckart-Wallach reaction has been reviewed (141). Examples of enamines reduced under the conditions of the Leuckart-Wallach reaction are listed in Table 12. 

For aliphatic monoamine [43], it is shown that secondary amines R2NH always possess a higher promoting effect for the polymerization of AAM and even the primary amine PA will enhance the polymerization with Rr = 1.47 and Ea = 36.4 kJ/mol, while the tertiary aliphatic amine TPA will not provide the polymerization due to some steric hindrance (Table 6). All of the data of cyclic amines listed in Table 7 are effective, i.e., NMMP with Rr = 1.81 and Ea = 29.9 kJ/mol showing the absence of steric hindrance. 

Amines remove the bulk of the H2S primary amines also remove the COj. Amine treating is not effective for removal of mercaptan. In addition, it cannot remove enough H2S to meet the copper strip corrosion test. For this reason, caustic treating is the final polishing step downstream of the amine units. Table 1-3 illustrates the chemistry of some of the important caustic reactions. 

Ring-opening products derived from primary amines are attractive precursors for the preparation of (3-lactams [57]. With methylmagnesium bromide as the base, diamino esters 33 cyclized readily in THF and stereospecifically generated anti-3-amino- 3-lactams 34 (Table 12.15). 

The nucleophilic displacement reactions with azide, primary amines, thiols and carboxylatc salts arc reported to be highly efficient giving high (>95%) yields of the displacement product (Table 9.25). The latter two reactions are carried out in the presence of a base (DBU, DABCO). Radical-induced reduction with tin hydrides is quantitative. The displacement reaction with phenolates,61j phosphines,6M and potassium phthalimide608 gives elimination of HBr as a side reaction. 

The present method utilizes dichlorocarbene generated by the phase-transfer method of Makosza4 and Starks.5 The submitters have routinely realized yields of pure distilled isocyanides in excess of 40%.6 With less sterically hindered primary amines a 1 1 ratio of amine to chloroform gives satisfactory results. Furthermore, by modifying the procedure, methyl and ethyl isocyanides may be prepared directly from the corresponding aqueous amine solutions and bromoform.7 These results are summarized in Table I. 

This procedure, which is based on the work of Ishii and co-workers, affords a mild and general method for converting a wide variety of esters to primary, secondary, and tertiary amides (Table 1). While the preparation of the tertiary amide, N,N-dimethylcyclohexanecarboxamide, described here is carried out in benzene, aluminum amides derived from ammonia and a variety of primary amines have been prepared by reaction with trimethylaluminum in dichloromethane and utilized for aminolysis in this solvent. Although 1 equivalent of the dimethylaluminum amides from amines was generally sufficient for high conversion within 5-48 hours, best results were obtained when 2 equivalents of the aluminum reagent from ammonia was used. Diethyl-aluminum amides can also effect aminolysis, but with considerably slower rates. 

Rosenblatt etal have examined the effect of structure and isotopic substitution upon the permanganate oxidation of some alky famines (Table 4). The isotope effect of 1.84 is considered to be sufficiently low to be compatible with aminium radical-cation formation, and it is felt that, while C-H cleavage is significant for oxidation of primary amines, the dominant mode of oxidation of tertiary amines is electron-transfer, e.g. 

The alkoxycarbonyl protecting groups can also be introduced into amines by, triazolides (Table 4—7). With A-tert-butoxycarbonyl-1,2,4-triazole the tert-butoxy-carbonyl protecting group (Boc) is transferred readily onto amino functions of primary amines, trimethylbenzyl ammonium salts of amino acids, or peptides.[ 1965 Alternatively, the Boc group can be transferred with terf-butylphenylcarbonate in the presence of 1,2,4-triazole. In this latter approach the triazolide is presumably formed as an intermediate. ... 

Tables 1 and 2 clearly show that the use of such alkali metal hydroxides as KOH, CsOH, and mixtures of KOH/NaOH allowed the reaction to proceed to a high DMAPN conversion with a very high selectivity for the primary amine. These results suggest that the highest selectivity in the hydrogenation of DMAPN to DMAPA is obtained with KOH, and mixtures of KOH/NaOH.

Caravaca et al. 339 evaluated the primary amines Primene 81R, Primene JMT (Table 5), and tridecylamine and concluded that for Primene 81R and tridecylamine the extraction occurs via,... 

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