Ethylamine, basicity

To minimize the formation of fuhninating silver, these complexes should not be prepared from strongly basic suspensions of silver oxide. Highly explosive fuhninating silver, beheved to consist of either silver nitride or silver imide, may detonate spontaneously when silver oxide is heated with ammonia or when alkaline solutions of a silver—amine complex are stored. Addition of appropriate amounts of HCl to a solution of fuhninating silver renders it harmless. Stable silver complexes are also formed from many ahphatic and aromatic amines, eg, ethylamine, aniline, and pyridine. 

Note The pre- and post-treatment of the chromatograms with the basic tri-ethylamine solution, which can be replaced by an alcoholic solution of sodium hydroxide [1,4] or a phosphate buffer solution pH = 8.0 (c = 0.2 mol/1) [5], serves to stabilize the fluorescence of the amino derivatives [2]. A final spraying with methanolic hydrochloric acid (chci = 5 mol/1) or 70% perchloric acid renders the detection reaction highly specific for histamine [4] and for catecholamines and indolamines [5]. 

As already reported in Table 6, the solubility of phosphazene polymers is strongly influenced by the nature of the substituent groups attached at the phosphorus atoms along the -P=N- skeleton. Water-solubility, for instance, can be induced in polyphosphazenes by using strongly polar substituents (e.g. methylamine [84], glucosyl [495], glyceryl [496], polyoxyethylene mono-methylether [273] or sulfonic acid [497,498] derivatives), or may be promoted by acids or bases when basic (amino substituents like ethylamine [499]) or acid (e.g. aryloxy carboxylate [499] or aryloxy hydroxylate [295]) substituents are exploited. 

A method for the preparation of olefins from primary amines is shown in equation 120. Treatment of 2-(4-bromophenyl)ethylamine (358) with acetic acid, acetic anhydride and sodium nitrite generates the nitroso amide 359, which decomposes to 4-bromostyrene in the presence of rhodium(II) acetate. The procedure is thus a mild, non-basic alternative to the classical Hofmann elimination of amines396,397. 

The CSAs that have been used most widely are 2,2,2-trifluoro-l-phenylethanol (TFPE, la), 2,2,2-trifluoro-l-(l-naphthyl)ethanol (TFNE, lb), 2,2,2-trifluoro-l-(9-anthryl)ethanol (TFAE, Ic), 1-phenylethylamine (PEA, 2a), and l-(l-naphthyl)ethylamine (NEA, 2b). Both enantiomers of TFPE, TFAE (9), PEA, and NEA are commercially available. The fluoroalcohols are relatively acidic and interact strongly with solutes having one or more basic sites (Sect. IV-B). Amines 2 have been used most often as CSAs for organic acids or other acidic solutes (Sect. IV-C). A number of analogs of TFAE have been studied (Sect. III-C). 

Accordingly, we find that a nitrile nitrogen (lone pair in an sp orbital) is not at all basic (pATa about — 10), though ethylamine (lone pair in an sp orbital)... 

Pre-eminent amongst examples is the case of amides, which do not show the typical basicity of amines. Acetamide, for example, has pATa — 1.4, compared with a 10.7 in the case of ethylamine. This reluctance to protonate on nitrogen is caused by delocalization in the neutral amide, in which the nitrogen lone pair is able to overlap into the n system. This type of resonance stabilization would not be possible with nitrogen protonated, since the lone pair is already involved in the protonation process. Indeed, if amides do act as bases, then protonation occurs on oxygen, not on nitrogen. Resonance stabilization is still possible in the D-protonated amide, whereas it is not possible in the A-protonated amide. Note that resonance stabilization makes the D-protonated amide somewhat less acidic than the hydronium ion (pATa — 1.7) the amide oxygen is more basic than water. 

As the distance between the amino groups increases, the effect of the NH2 on the first protonation diminishes, so that pATai values for the 1,3- and 1,4-diamino compounds are very similar to that of ethylamine. Only in 1,2-diaminoethane do we see the electron-withdrawing effects of the second amino group decreasing basicity. However, for the second protonation, it is clear that an ionized... 

The present preparation illustrates a general and convenient method for a two-step deoxygenation of carbonyl compounds to olefins. Related procedures comprise the basic decomposition of p-toluenesulfonylhydrazones, the hydride reduction of enol ethers, enol acetates, enamines, the reduction of enol phosphates (and/or enol phosphorodiamidates) by lithium metal in ethylamine (or liquid ammonia),the reduction of enol phosphates by titanium metal... 

Vanadium pentoxide dissolves in acids, both organic and inorganic, to form vanadyl or unstable vanadic salts,7 and in alkalis to produce ortho-, pyro-, meta-, and poly-vanadates. The physico-chemical changes involved when vanadium pentoxide is heated with various basic oxides in the powder state have been investigated by Tammann.8 On being digested with liquid ammonia slow absorption of ammonia takes place the composition of the product has not been definitely established.9 The oxide also dissolves in alcohols to produce esters,10 and combines with methylamine and ethylamine to form compounds of the type 2(R.NHB).V205, where R represents the alkyl radical.11... 

The available evidence supports the demethylation scheme and the identity of the initial red product as that of the basic tautomer of trimethylthionine (Azure B), as shown in eqs. 33 and 34. Addition of acid or other weak proton donor protonates the red dye to give the blue form. We have reexamined the reaction of MB or New methylene blue (NMB) in dry acetonitrile with tri-ethylamine (TEA). We have also found that a comparable reaction of NMB occurs with trimethylbenzylstannane (TMBS). Figure 8 shows changes in the visible spectrum of NMB which occur in addition of TEA. Table 12 lists quantitative data. The spectra... 

SYNTHESIS A stirred solution of 9.0 g 1 -(3,4-methylenedioxypheny l)-2-butanone (see the recipe for J for its preparation) in 150 mL MeOH was treated with 9.0 g ethylamine hydrochloride, 4.0 g anhydrous NaOAc, and 3.0 g sodium cyano-borohydride. The pH was maintained between 6 and 7 by the periodic addition of HC1. After the base formation had stabilized, there was added an additional 9.0 g ethylamine hydrochloride, 9.0 g NaOAc and 2.0 g sodium cyanoborohydride. With continuous stirring, there was HC1 added over the course of 1 h until the final pH was approximately 2. The reaction mixture was poured into 700 mL dilute NaOH, and extracted with 3x75 mL CH2C1,. These extracts were pooled, and back-extracted with dilute H2S04. This was washed with 2x50 mL CH,CI2, then made basic with dilute NaOH and extracted with 2x75 mL CH2Clr Removal of the solvent... 

Cryptands were found to react with metal solutions in basic solvents to generate the alkali metal cryptate and an alkali anion (alkalide), for example (Na[2.2.2])+Na (62, 63). 23Na-NMR measurements of this salt in methylamine, tetrahydrofuran, and ethylamine solutions showed that the Na resonance is shifted strongly upheld from the Na resonance (free or complexed) as shown in Fig. 7. The anion resonates at approximately the same frequency as that calculated for the free... 

Ethylamine is therefore easier to protonate (more basic) than 2-chloroethylamine. 

---