Amine, derivatives

Among the more important amine derivatives found in the body are a group of compounds known... 

N-henzyl-N-(2-phen5lethyl)-amine derivatives beUadine CigH25N03 pOI-06-4] (68) ... 

Xanthates and dithiophosphates dominate sulfide flotation usage, though several other collectors including more recently developed ones are gaining acceptance rapidly (43). As of this writing, this is an active area of research. Many of the sulfide collectors were first used ia the mbber iadustry as vulcanizers (16). Fatty acids, amines, and sulfonates dominate the nonsulfide flotation usage. The fatty acids are by-products from natural plant or animal fat sources (see Fats and fatty oils). Similarly petroleum sulfonates are by-products of the wood (qv) pulp (qv) iadustry, and amines are generally fatty amines derived from fatty acids. 

Many 1,2,3,5-benzenetetrol derivatives are used mediciaaHy. For example, khellin [82-02-0] (65), which is a naturally occurring benzopyranone, is used as a coronary vasodilator and bronchodilator (233). Derivatives of khellin are effective local anesthetics and antiarrythmics (234). Similarly, amine derivatives (68) that are prepared from khellinone oxime (66) exhibit hypnotic, sedative, anticonvulsant, antiinflammatory, cardiac analeptic, diuretic, and antiulcerous activity (235) (see Analgesics, antipyretics, and antiinflammatory agents). 

Potassium chloride coUectors are primary amines derived from beef taUow. Commercially available amine is a homogeneous mixture of palmityl-. 

When additional substituents ate bonded to other ahcycHc carbons, geometric isomers result. Table 2 fists primary (1°), secondary (2°), and tertiary (3°) amine derivatives of cyclohexane and includes CAS Registry Numbers for cis and trans isomers of the 2-, 3-, and 4-methylcyclohexylamines in addition to identification of the isomer mixtures usually sold commercially. For the 1,2- and 1,3-isomers, the racemic mixture of optical isomers is specified ultimate identification by CAS Registry Number is fisted for the (+) and (—) enantiomers of /n t-2-methylcyclohexylamine. The 1,4-isomer has a plane of symmetry and hence no chiral centers and no stereoisomers. The methylcyclohexylamine geometric isomers have different physical properties and are interconvertible by dehydrogenation—hydrogenation through the imine. 

Degradation of acid hydrazides or acyl azides to amine or amine derivatives. 

The half-lives shown in the table ". ill vary depending on the structure of the Fmoc-amine derivative. 

This tri-isocyanate is reported to impart good light stability and weather resistanee in polyurethane eoatings and is probably the most widely used aliphatic isocyanate. A number of other aliphatic polyisocyanates have been introduced recently in attempts to produce polyurethanes with improved light stability. Amine derivatives of diphenylmethane are made by reacting aniline of toluidines with formaldehyde. These can lead to a mixture of di-isoeyanates, the diphenylmethane di-isocyanates (MDIs) of commerce. Triphenylmethane-pp p"-tny tri-isocyanate is produced from leucorosaniline. 

Aziridines can best be obtained by ring closure of amine derivatives which contain a tm 5-oriented leaving group at the -position, see (89). The variable conformational and steric influences in the steroid skeleton limit the generality of a particular synthetic method and necessitate a selection of reagents based on the position of fusion of the aziridine ring. 

Trichloroacetic acid behaves somewhat similarly in that protonation of the enamine occurs l7J7d). Subsequent decarboxylation of the trichloro-acetate gives trichloromethyl anion, which adds to the iminium cation to give the trichloromethyl amine derivative. Thus the enamine (113) undergoes reaction with trichloroacetic acid to give N-[l-(trichloromethyl)cyclo-hexyl]-morpholine (8). The latter compound undergoes rearrangement on... 

The addition of phenylisocyanate to aldehyde-derived enamines resulted in the formation of aminobutyrolactams (438,439). As aminal derivatives these produets can be hydrolyzed to the linear aldehyde amides and thus furnish a route to derivatives of the synthetically valuable malonaldehyde-acid system. With this class of reactions, a second acylation on nitrogen becomes possible and the six-membered cyclization products have been reported (440). Closely related to the reactions of enamines with isocyanates is the condensation of cyclohexanone with urea in base (441). 

At low temperature a 1 1 adduct of thioacetic acid and an enamine could be prepared (709). The previously described reaction of aminomethylene ketones with hydrogen peroxide was extended to bisaminomethylene compounds. However, acylated cyclohexenamines led to cyclopentane-carboxamides (770), Trichloromethyl adducts of enamines and the rearranged amine derivatives were described in a further study (777). 

The formation of vinylogous amides from primary amines and -dicarbonyl compounds gives rise to hydrolyzable amine derivatives with greatly decreased nucleophilicity of the nitrogen function. Thus these derivatives have found some use as protecting groups in peptide syntheses 617-619). 

The Fmoc group is cleaved under mild conditions with an amine base to afford the free amine and dibenzofulvene. The accompanying table gives the approximate half-lives for the deprotection of Fmoc-ValOH by a variety of amine bases in DMF. ° The half-lives shown in the table will vary, depending on the structure of the Fmoc-amine derivative. 

Pd(Ph3P)4 and Bu3SnH convert the Alloc group to other amine derivatives when electrophiles such as (B0C)20, AcCl, TsCl, or succinic anhydride are added. Hydrolysis of the stannyl carbamate with acetic acid gives the free amine. 

Imidodisulfates can also be obtained by hydrolysis of nitridotrisulfates (see below). Figure 15.51 compares the structure of the imidodisulfate and parent disulfate ions, as determined from the potassium salts. Comparison with the hydroxyl-amine derivative K[HN(0H)S03] (below) is also instructive. 

The smooth intramolecular nucleophilic displacement of biphenyl carboxylic acids leading to benzocoumarins (See Section II.A.) inspired also investigation of the behavior of similar diphenyl ether, diphenyl sulfide and A-methyldiphenyl amine derivatives 458 under similar conditions. However, all these attempts to achieve cyclization to tricyclic compounds 459 were unsuccessful, probably due to the unfavorable stereochemistry for the formation of the required seven-mem-bered transition states and also to the presence of the deactivating bridge groups X (Eq. 42) [68JCS(C)1030]. 

Another route to the amido complexes originates from [(>j-Tp )W(CO) (PhC=CMe)(OTf)l and benzylamine and yields [(i -Tp )W(CO)(PhC=CMe) (NHCH2Ph)] (96JA6916). The latter can be protonated with tetrafluoroboric acid to give the amine derivative [(> -Tp )W(CO)(PhC=CMe)(NH2CH2Ph)](Bp4), and this process can be reversed by -butyllithium. Hydride abstraction by silver tetrafiuoroborate, molecular iodine, or PhsCPEe leads to the cationic imine derivatives [(> -Tp )W(CO)(PhC=CMe)(HN=CHPh)]". -Butyllithium deproto-nates the product and gives the neutral azavinylidene species [(> -Tp )W(CO) (PhC=CMe)(N=CHPh)]. The latter with silver tetrafiuoroborate forms the cationic nitrile species [(j -Tp )W(CO)(PhC=CMe)(N=CPh)](Bp4). 

The phenyl ethanol amine derivatives epinephrine (U and norepinephrine ( ) are intimately associated with the sympathetic nervous system. These two neurotransmitter hor-... 

Phenyl acetamides have a variety of pharmacological actions depending upon the nature of the amine-derived component. 

Reductive cleavage of phenylhydrazones of carbonyl compounds provides a route to amines. The reduction is carried out conveniently in ethanol containing ammonia over palladium-on-carbon. Ammonia is used to minimize formation of secondary amines, derived by addition of the initially formed amine to the starting material (160). Alternatively, a two-phase system of benzene, cyclohexane, toluene, or dioxane and aqueous hydrochloric acid can be used. 

This could be derived from tyrosine via the amine derivative, in a process similar to the production of P-phenylacetic add in CSL. 

Neurotransmitter and biogenic amine derived from the amino acid histidine synthesized in hypothalamic tuber-omamillary neurons (TMN) to maintain wakefulness, feeding rhythms, energy balance, neuroendocrine autonomic control, and memory functions prominent immu-nomodulator and proinflammatory signal released from mast cells in response to allergic reactions or tissue damage. 

A similar microwave-assisted cyclization in the presence of ammonium acetate of an a-ketoamide, obtained by acylation of an a-aminoketone, was recently described for the synthesis of the antifungal agent Nortopsedin D [46]. The problem of the instabiUty of the a-amino ketones was successfully resolved by in situ acylation of the amine derived from Staudinger reaction of the azide 50 with a phosphine (Scheme 16). This ketoamide was... 

An efficient chemoenzymatic route for the synthesis of optically active substituted indolines has been recently developed (Scheme 7.27), and also the alkoxycarbonyla-tion process is more efficient than the acylation reaction. Different lipases have been tested in the alkoxycarbonylation of these secondary amines, GALA being found to be the best biocatalyst for 2-substituted-indolines, and CALB for 3-methylindoline. The combination of lipases with a variety of allyl carbonates and TBME as solvent has allowed the isolation of the carbamate and amine derivatives in a high level of enantiopurity [51]. 

Proteins are also important nitrogen compounds. They constitute much of the cell materials, and are present in every type of organism known. In humans, muscle tissue, skin, and hair is mostly protein, about half of the dry weight of our bodies. From a chemical point of view, proteins are polymers of amino acids, alpha amine derivatives of carboxylic acids. Only about 20 different amino acids are actually found in proteins. It is the large number of variations in the protein chain, using only these... 

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