Simple primary amines

The reaction of phosgene with a primary aliphatic or aromatic amine Equation (10.1) is generally rapid, and takes place initially according to a 1 1 stoicheiometry, even at temperatures as low as -15 C [1861]  

The hydrogen chloride produced in this reaction reacts further with the amine to generate an ammonium salt, [RNH3]C1, which itself can react with further COClj Equation (10.2) [619,988,1154]  

This reaction proceeds at a much slower rate than the former reaction, and a variety of materials have been reported to catalyse it. 

The final product of the reaction of COCIj with a primary amine depends very much on the reaction conditions. If an excess of the amine is used at low temperatures then substituted ureas may form Equation (10.3)  

These are the products of the reaction when phosgene is bubbled into a solution of the amine in an inert solvent. Indeed, the reaction of phosgene with aniline constitutes a method for the quantitative determination of COClj (see Section 3.2.2) [e.g. 1168]  

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The kinetics of the hydrolysis of some imines derived from benzophenone anc primary amines revealed the normal dependence of mechanism on pH with ratedetermining nucleophilic attack at high pH and rate-determining decomposition of the tetrahedral intermediate at low pH. The simple primary amines show a linear correlation between the rate of nucleophilic addition and the basicity of the amine Several diamines which were included in the study, in particular A, B, and C, al showed a positive (more reactive) deviation from the correlation line for the simple amines. Why might these amines be more reactive than predicted on the basis of thei ... 

According to the information available, it would be reasonable to consider that P. stipticus emits light when its natural luciferin is oxidized with molecular oxygen in the presence of OJ and a suitable surfactant (Shimomura et al., 1993b). Also, it seems almost certain that the natural luciferin is formed from PS-A, PS-B and a simple primary amine by the addition and condensation reactions. 

The reactivity of epoxides can be modified by various proximal functionality. For example, 2,3-epoxy sulfides 118 are converted to the corresponding TMS-thiiranium species 119 upon treatment with TMS triflate. This intermediate reacts with O-silyl amides regiospecifically to form l-substituted-3-hydroxy-2-thioethers (e.g., 120). Simple primary amines undergo polyalkylation, but imines can be used as an indirect amine equivalent <96TET3609>. 

Kaesz et al. have shown that simple, primary amines (e.g. MeNH2) will react with Ru3(CO)12 to form p-acetamido ligands at temperatures as low as -15°C. We find that simple primary, secondary and tertiary alkyl amines will react with Ru3(CO) 2 at temperatures of 70-150°C to undergo catalytic deuterium for hydrogen exchange reactions on the hydrocarbon groups and transalkylation (52). We have found that a... 

The simple primary amines of the aliphatic series, then, do not form diazo-compounds because the reaction which would le, d to their formation only occurs at a temperature at which they are destroyed. The reactivity of the NH2-group can, however, be increased by a neighbouring carbonyl group. Thus we come to the case of the esters of the a-amino-carboxylic acids and of the a-amino-ketones. The ethyl ester of glycine can be diazotised even in the cold the diazo-compound which does not decompose under these conditions undergoes stabilisation by elimination of water and change into ethyl diazoacetate ... 

On account of their great lability the diazonium salts of the simple primary amines cannot be isolated from aqueous solution. On the other hand, they crystallise from alcohol when ether is added. Since the metallic salts of nitrous acid are insoluble in alcohol, its esters are used instead for diazotisation in alcohol. These esters are hydrolysed by acid with extraordinary rapidity and therefore behave almost like salts (see p. 147). 

Therefore, in principal, condensation of a primary amine with an enantiomerically pure ketone should allow asymmetric synthesis of a-substituted primary amines. This approach has been applied to the synthesis of a-amino acids, for example, using the imine prepared from a-amino esters and (l.S, 2,S ,5,S )-2-hydroxy-3-pinanone, via an amino-substituted ester enolate anion with some success39 40. Application of this approach to simple primary amines has seldom been reported. 

The similarity in pH-rate profile for the polymer (Fig. 20) and for simple primary amines or acetoacetate decarboxylase suggests that the mechanistic pathways of the decarboxylation reaction may also be alike. In the model amine and enzyme systems there is good evidence for the pathway shown in (33) ... 

These were first investigated and used in rubber as accelerators. Their effect in improving the vulcanizing and ageing properties of rubber was utilized for several years. Primary diamines, primary secondary amines and aminophenols are much more active than simple primary amines. Aminophenol and phenolamine salts are effective antidegradents. 

Clearly, the plethora of products to be expected, particularly those resulting from rearrangement (see Exercise 23-31), prevents the reaction of the simple primary amines with nitrous acid from having any substantial synthetic utility. 

The apparently exclusive formation of pyrimidine nucleosides of the 0 configuration in these reactions (no a isomers have been detected thus far) would seem more than fortuitous. In experiments with simple primary amines, these investigators229,234 have isolated acyclic compounds (such as LXVIII and LXXII, R = alkyl) this justifies their view that, in reactions with the D-ribosylamine derivative (LXX), analogous acyclic compounds are intermediates. Shaw233 has suggested that cyclization of the 0 anomer of these acyclic compounds would occur more readily than for the corresponding a anomer (which may accompany them). In the case of the a... 

The Sn2 reaction of amines with alkyl halides is complicated by a tendency for overalkylation to form a mixture of monoalkylated and polyalkylated products (Section 19-11). Simple primary amines can be synthesized, however, by adding a halide or tosylate (must be a good SN2 substrate) to a large excess of ammonia. Because there is a large excess of ammonia present, the probability that a molecule of the halide will alkylate ammonia is much larger than the probability that it will over-alkylate the amine product. 

The reaction of a simple primary amine, 1-aminocyclopropane, with aqueous lithium hypochlorite takes place readily at room temperature resulting in ring opening. Since the reaction competes with fragmentation to give ethene, the yield of 3-hydroxypropiononitrile, the ring-opened product, is modest (Table 15, entry 5). With 1-amino-1-methylcyclopropane, 4-hy-droxybutan-2-one is formed. 

All metal amination catalysts are active in the disproportionation of amines, which can lead to equilibration of primary, secondary, and tertiary amines. For example, for simple primary amines the initial step is the formation of an aldimine by dehydrogenation (Scheme 2). Subsequent addition of an amine and hydrogenation lead to a mixture of primary, secondary, and tertiary amines. The same active metal sites catalyze alcohol amination and amine disproportionation, which explains why the reactant alcohol inhibits disproportionation and selectivity for the desired amine drops considerably only after consumption of alcohol [2]. It is also evident from Scheme 2 that sufficient hydrogen present on the metal surface can reduce the concentration of imine and thus suppress disproportionation. 

The introduction of a second chiral residue in simple primary amines such as 1-phenylethyl-amine to give a secondary amine is also possible by catalytic hydrogenation of an imine ... 

Hydrochlorides of simple primary amines have been little studied, but appear similar to those of amino-acids. Methylamine hydrochloride, for example, absorbs at 3075 cm" and at 2972 cm", and has an NH deformation band [84] at 1617 cm". In hydroxylamine hydrochloride the NH bonds are more strongly associated and are assigned [84] at 2955 cm" and 2667 cm". ... 

How would you expect the following classes of compounds to compare with simple primary amines as bases and acids ... 

TiVhen simple primary amines are treated with a large excess of 30 per cent formaldehyde solution at low temperatures, cyclic triformals are produced. Bergmann and Miekeley isolated these products by extracting the... 

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