Amide , amines from reaction with

The ketocarbene 4 that is generated by loss of Na from the a-diazo ketone, and that has an electron-sextet, rearranges to the more stable ketene 2 by a nucleophilic 1,2-shift of substituent R. The ketene thus formed corresponds to the isocyanate product of the related Curtius reaction. The ketene can further react with nucleophilic agents, that add to the C=0-double bond. For example by reaction with water a carboxylic acid 3 is formed, while from reaction with an alcohol R -OH an ester 5 is obtained directly. The reaction with ammonia or an amine R -NHa leads to formation of a carboxylic amide 6 or 7 ... 

Zinc carbamate complexes are well known, and the structural types and stabilities can be compared with thiocarbamates and dithiocarbamates which are discussed in Sections 6.8.11.1.3 and 6.8.7.1.4482 Carbamates of zinc can be formed from the reaction of carbon dioxide with alkylzinc alkyl amides and further reaction with alkylzinc can give a distorted cubane structure.483 The tetrameric diethylcarbamate species initially formed can also be used to produce monomeric or dimeric carbamate structures in reaction with amines tetramethylethylenediamine forms a monomer [(Me2NCH2)2Zn(02CN(C2H5)2)2] with an octahedral zinc center and pyridine forms a dimer[CsH5NZn2Me(02CN(C2H5)2)3] with tetrahedral zinc centers.484... 

Aliphatic amides possess more strong a-C—H bonds in comparison with amines. This is the result of the carbonyl group influence on the stabilization of the formed a-amidoalkyl radical formed from amide in the reaction with the peroxyl radical. This influence is not so strong as that of the amine group. The values of the a-C—H bond in a few amides were estimated recently by the IPM method [4] and are given here. 

An electrochemical method for the synthesis of a series of 4-(alkylamino)-2-phenyloxazolines 139a-f from A -(2,2-dichlorovinyl)amides 135 has been reported. The starting A -(2,2-dichlorovinyl)amide 135, readily available from chloral and amides, undergoes facile reaction with amines to give 136. Cathodic reduction of 136 generates chlorocarbanionic intermediates 137 and 138 that... 

Alkylpyridines are aminated preferentially at the 2-position, but reaction is slower than in the parent system. Quinoline is difficult to aminate and only a low yield of 2-aminoquinoline (32%) is obtained from reaction with sodamide in toluene. When dimethylaniline is employed as solvent, 2-amino-3,4-dihydroquinoline (24%) becomes the major product, and the yield of 2-aminoquinoline drops to 7%. The best yields of 2-aminoquinoline (53-69%) have been obtained by using barium or potassium amide in liquid ammonia. Use of the potassium salt also produces a 10% yield of the 4-amino isomer. The... 

Amines undergo reactions with carboxylic acids comparable to the formation of esters from alcohols. The product is known as an amide. 

Amides. Amides can be prepared in one step from a carboxylic acid and an amine by reaction with 1 (1 equiv.) and triethylamine (2 equiv.) in CH2C12 at 25°. Presumably a mixed anhydride is first formed, which reacts subsequently with the amine. A variation involves conversion of the carboxylic acid into the carboxylic anhydride by reaction with 1 (0.5 equiv.) and triethylamine subsequent addition of the amine results in the formation of the amide. Yields are generally greater than... 

There are several types of chiral derivatizing reagents commonly used depending on the functional group involved. For amines, the formation of an amide from reaction with an acyl halide [147,148], chloroformate reaction to form a carbamate [149], and reaction with isocyanate to form the corresponding urea are common reactions [150]. Carboxyl groups can be effectively esterified with chiral alcohols [151-153]. Isocynates have been used as reagents for enantiomer separation of amino acids, iV-methylamino acids, and 3-hydroxy acids [154]. In addition to the above-mentioned reactions, many others have been used in the formation of derivatives for use on a variety of packed and capillary columns. For a more comprehensive list, refer to References 155-159. 

Confirmatory, if incomplete, support for the structures of the tV-methy 1-amine (XXVII) and tV-methy 1-amide (XXVIII) byproducts was obtained from reactions with AIC as follows26 ... 

Tris(organoamino)boranes have been utilized to prepare, in reasonable yields,4,5 mono- and dihalo(organoamino)boranes which are often difficult to obtain by direct amination of the boron trihalides. Carboxylic acids, 1,3-diketones, ketones, and /3-ketoesters have been converted into carboxamides, enamino-ketones, enamines, and j -enamino-amides, respectively, by reaction with an appropriate tris(organoamino)borane under very mild conditions.6 Sulfenamides (R2NSC6H5) have also been prepared in high yield from selected tris(organoamino)boranes and sulfenic esters under relatively mild conditions.7... 

MET-CAMO was prepared from 5/ -methylthebaine (57) [109,110] via 14/ -amino-7,8-dihydro-5/ -methylcodeinone (59) which was obtained by the Kirby-McLean procedure [111]. Thus, oxidation of 2,2,2-trichloroethyl A-hydroxycarbamate with sodium periodate in the presence of 5/ -methylthebaine gave the adduct (58). Catalytic hydrogenation using a Pd/C catalyst in methanol in the presence of sodium acetate-acetic acid buffer yielded amine (59). Reaction with 4-nitrocinnamoyl chloride furnished amide (60) and ether cleavage using boron tribromide yielded MET-... 

The reaction of ketene 24 with triethylarnine in acetonitrile gave an initial observable zwitterion from reaction with triethylarnine, and this was found to give a further amine catalyzed reaction leading to a product diethyl amide 184, with dealkylation (Eqns (4.122)), for which an elimination pathway was proposed. ... 

The hydroamination of dienes with basic primary and secondary amines can be achieved with a variety of catalysts including aUcah metals and their readily available derivatives. Reactions of acyclic 1,3-dienes catalyzed by alkah metals [159, 160, 171], metal hydrides [172], and metal amides (generated from metal alkyls) [163, 173, 174] result in regioselective formation of the stericaUy less hindered 1,4-addition product in most cases (23) [174]. Primary aliphatic amines are capable of performing double hydroamination in these conditions, typically leading to complex mixtures of mono- and bis-aUyl amines, whereas reactions with secondary amines are more practical [160]. 

The reaction is applicable to the preparation of amines from amides of aliphatic aromatic, aryl-aliphatic and heterocyclic acids. A further example is given in Section IV,170 in connexion with the preparation of anthranilic acid from phthal-imide. It may be mentioned that for aliphatic monoamides containing more than eight carbon atoms aqueous alkaline hypohalite gives poor yields of the amines. Good results are obtained by treatment of the amide (C > 8) in methanol with sodium methoxide and bromine, followed by hydrolysis of the resulting N-alkyl methyl carbamate ... 

Some of the physical properties of fatty acid nitriles are Hsted in Table 14 (see also Carboxylic acids). Eatty acid nitriles are produced as intermediates for a large variety of amines and amides. Estimated U.S. production capacity (1980) was >140, 000 t/yr. Eatty acid nitriles are produced from the corresponding acids by a catalytic reaction with ammonia in the Hquid phase. They have Httie use other than as intermediates but could have some utility as surfactants (qv), mst inhibitors, and plastici2ers (qv). 

The biochemical basis for the toxicity of mercury and mercury compounds results from its ability to form covalent bonds readily with sulfur. Prior to reaction with sulfur, however, the mercury must be metabolized to the divalent cation. When the sulfur is in the form of a sulfhydryl (— SH) group, divalent mercury replaces the hydrogen atom to form mercaptides, X—Hg— SR and Hg(SR)2, where X is an electronegative radical and R is protein (36). Sulfhydryl compounds are called mercaptans because of their ability to capture mercury. Even in low concentrations divalent mercury is capable of inactivating sulfhydryl enzymes and thus causes interference with cellular metaboHsm and function (31—34). Mercury also combines with other ligands of physiological importance such as phosphoryl, carboxyl, amide, and amine groups. It is unclear whether these latter interactions contribute to its toxicity (31,36). 

---