Ethylamine, reaction

There can be little question that excitation of metal amide is the initial step in both solvent systems. However, it is not clear at the outset whether ion pairs or free ions are involved. No direct measurements of the dissociation constant of potassium ethylamide in ethylamine are available. In ammonia, the value K = 7.3 X 10 5 M has been obtained (17) from conductivity data at —33.5° C. The temperature coefficient of K appears to be small (18), and this value will be assumed also at —78 ° C. In ethylamine, the dissociation constant must be considerably smaller than this, and in the concentration range of our experiments in ethylamine (0.5 to 1.5 X 10 -3 M) most of the salt will be present as ion pairs. We therefore write for the ethylamine reaction ... 

As part of a programme designed to produce compounds with axial chirality, double Bischler-Napieralski reactions were carried out with oxamide derivatives of co-arylalkylamines. Thus, treatment of the oxamide derived from 3,4-dimethoxy- P -pheny lethylamine with pyrophosphoryl chloride in acetonitrile gave 1 in 84% yield, as expected. An attempt was then made to extend this double cyclisation protocol to the oxamide derived from 2-(3-methoxyphenoxy)ethylamine. Reaction of this latter compound under the same conditions used for the formation of 1, however, gave 2 in 81% yield instead of the expected product of a double Bischler-Napieralski reaction. 

Ethyl a-acetyl-j3-(2,3-dimethoxy-phenyl)acrylate, 31, 56, 58 Ethyl a-acetyl-/S-(3,4-dimethoxy-phenyl)acrylate, 31, 58 ETHYL a-ACETYL-/3-(2,3-DIMETH0XY-phenyl)propionate, 31, 56 Ethyl a-acetyl-j3-(3,4-dimethoxy-phenyl)propionate, 31, 58 Ethylamine, reaction with chloroform, 35, 64... 

These large rate enhancements are attributable to the copper(II) ion complexing with penicillin [26] because methylation of the free carboxylate group in benzylpenicillin reduces the rate of the copper(II) ion-trifluoro-ethylamine reaction by ca 10. There is no kinetic dependence upon the concentration of trifluoroethylamine which indicates that aminolysis does... 

Pyridine has been used effectively as a catalyst in the Kno-evenagel condensation reaction. Depending upon the nature of the base employed, the product selectivity can be altered. Different stereochemistry has been observed for aromatic heterocyclic bases such as pyridine and aliphatic tertiary amines such as tri-ethylamine. Reaction of hexanal (4) with malonic acid (5) in the presence of pyridine as the base gives the Q , -unsaturated acid (6) as the major product (91 9 When bases such as triethy-... 

The acidic properties of sulphonamides and their mono-substitution derivatives are particularly well illustrated in the alkyl ubstitution compounds, which by reason of these properties can be prepared by two distinct methods. Thus mono- and di-ethylamine, when subjected to the Schotten-Baumann reaction using benzenesulphonyl chloride, gi e benzenesulphonethylamide, and bcnzenesulphondiethylamide respectively. These compounds can also... 

Acetophenone similarly gives an oxime, CHjCCgHjlCtNOH, of m.p. 59° owing to its lower m.p. and its greater solubility in most liquids, it is not as suitable as the phenylhydrazone for characterising the ketone. Its chief use is for the preparation of 1-phenyl-ethylamine, CHjCCgHslCHNHj, which can be readily obtained by the reduction of the oxime or by the Leuckart reaction (p. 223), and which can then be resolved by d-tartaric acid and /-malic acid into optically active forms. The optically active amine is frequently used in turn for the resolution of racemic acids. 

So now we have a modified method where one has ammonia, methylamine or ethylamine freebase saturated in a small amount of DMF. The author next suggested that a power pulse protocol would not necessarily be needed, but that the power output from the microwave should be between 20-40% of full power. Also, the water in the clay would still be needed for the reaction. 

Schatzmann, in 1891, tried to prepare 2-thiazolines by hydrogenation of thiazoles and by the action of sodium and ethanol on 2,4-dimethyl-thiazole, 2-methylthiazole, and 2-methyl-4-phenylthiazole (476). None of these substrates was reduced to thiazoline the second gave no reaction and the first underwent ring cleavage, leading to a mixture of n-propylmercaptan and ethylamine (Scheme 90). Three years later the same... 

The concentration of phenylacetate can be determined from the kinetics of its pseudo-first-order hydrolysis reaction in an ethylamine buffer. When a standard solution of 0.55 mM phenylacetate is analyzed, the concentration of phenylacetate after 60 s is found to be 0.17 mM. When an unknown is analyzed, the concentration of phenylacetate remaining after 60 s is found to be 0.23 mM. What is the initial concentration of phenylacetate in the unknown ... 

The reaction of a hydroperoxide with 2-methylaziridine [75-55-8] has been described (94). The reaction of ethyleneknine with phenols (95) and carboxyHc acids (96,97) produces ethylamine ethers and esters, respectively. However, these reactions frequentiy yield product mixtures which contain polyaminoalkylated oxygen nucleophiles and polymers, in addition to the desked products (1). The selectivity of the reaction can often be improved by using less than the stoichiometric amount of the aziridine component (98,99). 

A number of 2eohtic materials have been claimed to cataly2e this reaction and reaction temperatures are on the order of 200—350°C with pressures as high as 18000 kPa (2600 psi) reported. This is a low conversion process and recycle of the unconverted starting materials is necessary to provide an economical process. Amination of ethylene to produce ethylamines cataly2ed by ammonium iodide is reported, but not beheved to be practiced commercially (15,16). Alkyl Halide Amination (Method 7). The oldest technology for pioducing amines is the reaction of ammonia with an alkyl hahde. This... 

Reaction of ethyl chloride with an alcohoHc solution of ammonia yields ethylamine, diethylamine, triethylamine, and tetraethyl ammonium chloride (10,11) (see Amines, lower aliphatic). 

Ethylamines. Mono-, di-, and triethylamines, produced by catalytic reaction of ethanol with ammonia (330), are a significant outlet for ethanol. The vapor-phase continuous process takes place at 1.38 MPa (13.6 atm) and 150—220°C over a nickel catalyst supported on alumina, siUca, or sihca—alumina. In this reductive amination under a hydrogen atmosphere, the ratio of the mono-, di-, and triethylamine product can be controlled by recycling the unwanted products. Other catalysts used include phosphoric acid and derivatives, copper and iron chlorides, sulfates, and oxides in the presence of acids or alkaline salts (331). Piperidine can be ethylated with ethanol in the presence of Raney nickel catalyst at 200°C and 10.3 MPa (102 atm), to give W-ethylpiperidine [766-09-6] (332). 

Special reactions of hydrazides and azides are illustrated by the conversion of the hydrazide (205) into the azide (206) by nitrous acid (60JOC1950) and thence into the urethane (207) by ethanol (64FES(19)105Q) the conversion of the same azide (206) into the N-alkylamide (208) by ethylamine the formation of the hydrazone (209) from acetaldehyde and the hydrazide (205) and the IV-acylation of the hydrazide (205) to give, for example, the formylhydrazide (210) (65FES(20)259). It is evident that there is an isocyanate intermediate between (206) and (207) such compounds have been isolated sometimes, e.g. (211). Several of the above reactions are involved in some Curtius degradations. 

The submitters report that both l,4-diazabicyclo[2.2.2]octane and triethylamine have been used to catalyze this decomposition. Tri-ethylamine was less satisfactory as a catalyst because of its relatively rapid reaction with the solvent, carbon tetrachloride, to form triethylamine hydrochloride and because of difficulty encountered in separating triethylamine from the dicarbonate pi oduct. The 1,4-diazabicyclo-[2.2.2]octane was efficiently separated from the dicarbonate product by the procedure described in which the crude product was washed with very dilute aqueous acid. 

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]. 

Zincke-type salts derived from other aromatic nitrogen heterocycles also undergo Zincke reactions. The isoquinolinium salt 6 (Scheme 8.4.16) permitted incorporation of a phenyl ethylamine chiral auxiliary, providing salt 48. In this context and others (vide infra), Marazano and co-workers found that refluxing -butanol was a superior solvent system for the Zincke process. Additionally, the stereochemical integrity of the or-chiral amino fragment was reliably maintained. 

To understand the unpredictable nature of the Pictet-Gams reaction, Hartwig and Whaley conducted the first mechanistic studies in 1949. Their work focused on substituent effects when directly attached to the ethylamine side chain. They also investigated a variety of dehydration agents in order to identify optimal reaction conditions. It was determined that formation of the isoquinoline structure was virtually impossible when alkyl or phenyl substituents were placed in the 4-position of the ethylamine side chain. 

Hartwig and Whaley suggested that when substituents are placed in the 4-position of the ethylamine side chain, an oxazoline intermediate (7) is formed a side reaction that was first mentioned by Krabbe in 1940. However, Hartwig and Whaley did not isolate the putative intermediate. 

The reactions of (174) with various amines has been studied." " Hydrolysis of the hexamine salt of (174) gave not the symmetric diamine but (184) via a cyclic intermediate. The pyrolysis of 5-methyl-2-thenyltrimethyl ammonium hydroxide (185) is claimed to give (186) through a 1,6 Hofmann elimination reaction. The Bischler-Napieralski cyclization has been applied to acetyl derivatives of 2-(2-thienyl) ethylamine and 2-(3-thienyl) ethylamine for the preparation of sulfur analogs of isoquinoline. ... 

When diazomethane is slowly added to excess lactam, the anions formed can interact with unreacted lactam by means of hydrogen bonds to form ion pairs similar to those formed by acetic acid-tri-ethylamine mixtures in nonpolar solvents. The methyldiazonium ion is then involved in an ion association wdth the mono-anion of a dimeric lactam which is naturally less reactive than a free lactam anion. The velocity of the Sn2 reaction, Eq. (7), is thus decreased. However, the decomposition velocity of the methyldiazonium ion, Eq. (6a), is constant and, hence, the S l character of the reaction is increased which favors 0-methylation. It is possible that this effect is also involved in kinetic dependence investigations have shown that with higher saccharin concentrations more 0-methylsaccharin is formed. 

Progressive departure from the fundamental structure of the lead agent cimetidine led to the anti ulcer agent oxmetidine (47). The synthesis involves -methylation (CH3I) of the 2-thiouracil intermediate and is followed by an addition-elimination reaction with 2-(5-methyl-4-imidazolylmethylthio) ethylamine to give oxmetidine (47). ... 

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