Formate, ammonium, with amines

The conversion of an aldehyde or ketone into the corresponding amine by heating with ammonium formate or with formamide and formic acid at about... 

The mechanism of the reaction involves the intermediate formation of an amine cyanate (see previous Section) in aqueous solution urea behaves as an equifi-brium mixture with ammonium cyanate ... 

Salt Formation. Salt-forming reactions of adipic acid are those typical of carboxylic acids. Alkali metal salts and ammonium salts are water soluble alkaline earth metal salts have limited solubiUty (see Table 5). Salt formation with amines and diamines is discussed in the next section. 

In attempts to impart physicochemical properties of a "quat" synthesized VPI-5 to an "amine" synthesized VPI-5, we conducted several exploratory syntheses using mixtures of amines and quats. Some of our results are illustrated in Table 1. The quaternary ammonium hydroxides were added just after the addition of the amine using the synthesis procedure outlined above. First, it is apparent that a small amount of a "quat" can influence the synthesis of VPI-5. When using DPA, 1/80 or 1/60 TMA extends the time that VPI-5 is stable in the mother liquor. Also, 1/40 TMA inhibits the formation of VPI-5. Quats other than TMA appear to perform the same tasks as TMA. Since TMAOH is inexpensive, we continued to explore the use of TMAOH with other amines. The data in Table 1 show that TMAOH can be used with amines other than DPA to crystallize VPI-5. To date TIPOA appears to give the best VPI-5 product which fortunately also is obtained in high yield. 

In conclusion, SNAr reactions are often facihtated by polar protic solvents such as butanol or by polar solvents in the presence of Brpnsted or Lewis acids. When displacements of halides with amines are used, both polar and protic solvents can solubilize the ammonium halides resulting from the reactions, and lead to the formation of Brpnsted acids. Fluoride or chloride ions are preferred leaving groups for this reaction. Suliinyl and sulfenyl groups require somewhat harsher conditions. 

Leland and Powell also studied ECL obtained from reaction of [(bpy)3Ru]3+ with trialkylamines [47], Since the mechanism involves an electron transfer from the amine to Ru3+, there exists an inverse relationship between the first ionization potential of the amine and ECL intensity. The relative intensity of [(bpy)3Ru]2+ ECL was found to be ordered tertiary > secondary > primary. Quaternary ammonium ions and aromatic amines do not produce ECL with Ru(II) diimine complexes. Brune and Bobbitt subsequently reported the detection of amino acids by [(bpy)3Ru]2+ ECL [28,29], Employing capillary electrophoresis for separation, the presence of various amino acids can be detected directly by reaction with [(bpy)3Ru]3+ generated in situ with up to femtomo-lar sensitivity and with a selectivity for proline and leucine over other amino acids. The formation of an amine radical cation intermediate is characteristic of proposed mechanisms of both aliphatic amines and amino acids. 

Macroscopic solvent effects can be described by the dielectric constant of a medium, whereas the effects of polarization, induced dipoles, and specific solvation are examples of microscopic solvent effects. Carbenium ions are very strong electrophiles that interact reversibly with several components of the reaction mixture in addition to undergoing initiation, propagation, transfer, and termination. These interactions may be relatively weak as in dispersive interactions, which last less than it takes for a bond vibration (<10 14 sec), and are thus considered to involve "sticky collisions. Stronger interactions lead to long-lived intermediates and/or complex formation, often with a change of hybridization. For example, onium ions are formed with -donors. Even stable trityl ions react very rapidly with amines to form ammonium ions [41], and with water, alcohol, ethers, and esters to form oxonium ions. Onium ion formation is reversible, with the equilibrium constant depending on the nucleophile, cation, solvent, and temperature (cf., Section IV.C.3). 

Many water-insoluble ketones, aliphatic, aryl aliphatic, and heterocyclic, respond favorably to treatment with ammonium formate or formamide to form with subsequent hydrolysis the primary amines. A typical procedure for the synthesis of a-phenylethylamine (66%) from acetophenone and ammonium formate has been applied to many other ketones (65-84%). Nuclear alkoxyl, halo, and nitro groups are not disturbed. The reaction with formamide as the reducing agent is catalyzed by ammonium formate, ammonium sulfate, or magnesium chloride. ... 

Chloride is determined by mercurimetric titration to the sodium nitroprusside end-point. Carbonates, acetates and borates do not interfere in the titration but large amounts of ammonium salts do interfere. The method has been applied to methyltrichlorosilane, dimethyldichlorosilane, diethyldichlorosilane, phenylmethyldichlorosilane and phenyltrichlorosilane. Methods have been described76,77 based on reaction with amines for the determination of chlorine directly linked to silicon in alkyl aryl chlorosilanes. One method76 is based on the formation of aniline hydrochloride according to the equation ... 

The composition of the reagent gas plasma is controlled by the mobile phase composition. It contains reactant ions of the type HsO, CH30H2, CHsCNH, etc., in most cases solvated by solvent molecules, for example, CH30H2 (H20)n(CH30H)ni with n + m < 4. The presence of ammonia vapor, for example, as a result of the evaporation of ammonium acetate added to the mobile phase, causes rapid removal of protonated solvent ions with formation of ammonium ions that become the dominant reagent gas ions. The addition of alkylamines or acids to the mobile phase results in the formation of protonated amines or anions as the dominant species in the reagent gas plasma. Since highly reactive ions, such as CHs" ", can not be formed by APCI in the presence of solvents, it is not possible to ionize saturated hydrocarbons or other compounds of low gas-phase basicity. 

Reductive amination of an aldehyde or ketone with ammonia or a primary amine can sometimes be problematic, as the product amine can undergo further reductive amination with the starting carbonyl compound. One method that promotes selective formation of primary amines uses the rhodium(lll) complex [RhCp Cl2]2 as a catalyst and ammonium formate (HCOONH4), which acts as the source of the ammonia and the hydride (7.87). ... 

To coimter the loss of water dining the process and a significant degradation of the material, to prevent, e.g., the formation of cellular stractures output from an extruder, and to obtain a material with controlled properties, we use a non-volatile plasticizer such as glycerol or other polyols (sorbitol, xylitol, fructose, polyethylene glycol, etc.) [AVE 04a, XIE 12]. Blends of these different polyols are also used [CHI 10b]. Other, notably nitrogenous plasticizers (urea, ammonium derivatives, amines, etc.) can also be used. Plasticized starches are thus created. They are... 

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