Primary amine definition

The reaction of CDI with primary phosphines was expected to lead first to an azolide ImCOPHR, analogous to imidazole-N-carboxamide as the reaction product of primary amines and CDI. In fact, reaction of phenylphosphine with CDI leads directly to imidazole, carbonmonoxide, and tetraphenylcyclotetraphosphine (THF, reflux, 5h). In analogy to the dissociation of imidazole-AT-carboxamide into isocyanates and imidazole, this can be explained by the assumption that the first-formed ImCOPHC6H5 dissociates into an isocyanate analogue, C6H5P=C=0, which is unstable and decomposes into carbon monoxide and phenylphosphene (C6H5P) which tetramerizes. However, the intermediate formation of phenylphosphene has not yet been definitely proved. 

It is not possible to propose a general mechanism from these studies, for results do not correspond to a definite pattern. Although, in all the systems, secondary amines are the most effective inhibitors, the role played by tertiary amines is confusing. In several systems (Table I, No. 1, 2, and 3) tertiary amines are much more effective than primary amines, but in others they appear to have little or no effect. Again, in acetaldehyde oxidation (Table I, No. 1 and 2) there is generally a linear relationship between the amount of inhibitor added and the induction period before either slow oxidation or ignition of the fuel occurs. In other systems (Table I, No. 3, 4, and 5), however, a much more complex relationship is obtained. Thus, amines may be acting by different mechanisms in different systems. 

Primary amines may be readily distinguished from secondary and tertiary analogues by the presence of two absorption bands in the infrared spectrum between 3320 and 3500 cm-1 (symmetric and antisymmetric NH str.). Secondary amines exhibit a single absorption band at about 3350 cm-1 (NH str.). In both cases deformation modes for the NH bond appear at about 1600 cm-1. There is no satisfactory absorption to allow a definitive characterisation in the case of tertiary amines. In the nuclear magnetic resonance spectrum of primary and secondary amines, the nitrogen-bound hydrogens are recognisable by their replaceability on the addition of deuterium oxide. 

This classification is illustrated in Scheme 291. By definition, imidazole synthesis under this classification requires an amine or its derivatives as one of the starting materials. Enamines, imines, and isonitriles have been used as the other reactants. Thus, reaction of primary amines with methyl 3-bromo-2-isocyanoacrylates 1189 leads to methyl 1,5-disubstituted imidazole-4-carboxylates 1190, which can undergo decarboxylation to give 1,5-disubstituted imidazoles 1191 (Scheme 292) <1996JME596>. 

Azide synthesis (2, 415). In the definitive paper3 describing the conversion of primary amines into azides by a diazo transfer reaction, methyllithium is preferred to methylmagnesium chloride as the base. The reaction has been extended to hydrazones. Thus, when the hydrazones of benzophenone, fluorenone, and acetophenone are treated with methylmagnesium chloride and then with tosyl azide, the corresponding diazoalkanes are obtained in about 20% yield. 

In general, these two reactions are definitely not suitable for the preparation of appreciable quantities of pure isonitriles indeed, they have been largely replaced by the more widely applicable dehydration method [lc,d,fj. This was first discovered by Hagedorn in 1956 and entails transformation of primary amines into for-mamides, followed by dehydration either with phosgene (or its precursors) and triethylamine, or phosphorus oxychloride and di-wo-propylamine [If]. 

Classification Primary aliphatic amine Definition Primary aliphatic amine of palmitic acid Empirical C16H35N Formula CH3(CH2)i4CH2NH2 Properties Wh. solid char, amine odor m.w. 241.52 m.p. 39 C cationic Toxicology LD50 (IP, mouse) 200 mg/kg TDLo (oral, mouse) 40 mg/kg poison by IP route experimental teratogen and reproductive effects TSCA listed... 

Classification Primary aliphatic amine Definition Primary aliphatic amine derived from tallow acid... 

Tsogoeva and coworkers reported the use of oligopeptides of 4-tram-aminopro-hne (tetra- and dipeptides 3 and 4, respectively) as organic catalysts for the Michael reaction of nitroalkanes to cyclic enones. The reaction, in the presence of the achiral additive trans-2,5-dimethylpiperazine, afforded the conjugate addition product in excellent yield and ee up to 88% (Scheme 5.2) [14]. Other dipeptides, with a primary amine at the N-terminus and containing a histidine derivative, were definitely less selective [15] (under the same reaction conditions), while L-proline alone afforded the same product in 93% ee [16]. 

Hexadecylamine n-Hexadecylamine Palmityl amine Classification Primary aliphatic amine Definition Primary aliphatic amine of palmitic acid Ionic Nature Cationic Empirical C,jH 35 ... 

The second way, called the Bunnett-Olsen method,30 makes the less drastic assumption that log activity coefficient ratios such as those in equation (7) are linear functions of one another, rather than cancelling out. From the definition of H0 in equation (8) we can write equation (11), where Am refers to the primary aromatic amines used in the determination of Ho, and then any specific activity coefficient ratio, say for the weak base B, is assumed to be linear in this according to equation (12) ... 

The formation of anionic -adducts resulting from the primary attachment of neutral nucleophiles followed by proton elimination has been described only occasionally. A definite example is the reaction of methyl-amine with 2-nitrophenazine 10-oxide in DMF, leading to adduct 118.161 This structure is well supported by spectral evidence. It is characterized by two... 

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