C-Aroylations of imides and N-aroylations of β-keto amides with aromatic esters by means of sodium hydride to form β-keto imides

1968 ◽  
Vol 46 (15) ◽  
pp. 2561-2566 ◽  
Author(s):  
James F. Wolfe ◽  
George B. Trimitsis ◽  
Charles R. Hauser
Keyword(s):  
Liquid Ammonia ◽  
Sodium Hydride ◽  
Amide Group ◽  
Methyl Groups ◽  
Aromatic Esters ◽  
Synthetic Utility ◽  
C And N ◽  
Hydride Method ◽  
Better Than

Aroylations at the methyl groups of N-acetylbenzamide and p-benzoylaminoacetophenone, and at a methylene position of succinimide with appropriate aromatic esters were effected by means of sodium hydride in refluxing monoglyme. Benzoylation at the amide group of α-benzoylacetamide and salicylamide were accomplished similarly. The yields of β-keto imides from these C- and N-aroylations by sodium hydride, with which intermediate dianions were evidently not formed, were generally much better than those obtained through dianions produced by means of an alkali amide in liquid ammonia. The synthetic utility of the sodium hydride method is discussed.

Convenient new synthesis of 1,3-diaroylureas

1969 ◽  
Vol 47 (11) ◽  
pp. 2097-2099 ◽  
Author(s):  
James F. Wolfe ◽  
George B. Trimitsis
Keyword(s):  
Sodium Hydride ◽  
Aromatic Esters ◽  
New Synthesis ◽  
Excess Sodium

It has been found that symmetrical 1,3-diaroylureas can be prepared in good yields by allowing urea to react with aromatic esters and excess sodium hydride in refluxing 1,2-dimethoxyethane. Applications of this method to the synthesis of unsymmetrical 1,3-diaroylureas and substituted monoaroylureas are also described.

Effect of Microwave Drying on Dyeing Rate of Cotton Yarn

2011 ◽  
Vol 328-330 ◽  
pp. 1619-1622 ◽  
Author(s):  
Zi Na Zhu ◽  
Zhuo Meng ◽  
Guang Chao An ◽  
Yi Ze Sun
Keyword(s):  
Liquid Ammonia ◽  
Engineering Application ◽  
Experimental System ◽  
New Method ◽  
Microwave Drying ◽  
Good Effect ◽  
Cotton Yarn ◽  
Steam Drying ◽  
Dyeing Rate ◽  
Better Than

Focusing on the residual amount of liquid ammonia in modified cotton yarn, this paper presents a new method of drying the liquid ammonia by microwave. An experimental system is designed to find whether this new method is correct and to analyse the effect of microwave drying on the dyeing rate of cutton yarn. Firstly, the microwave drying experiment is carried out to prove that this new drying method is better than the traditional steam drying way. Then, another contrast experiment on the dyeing rate confirms the good effect of microwave drying. So it is concluded that microwave drying is an efficient and energy-saving way to remove the remaining liquid ammonia. Meanwhile, the experimental results provide the relevant data to make guiding sense to engineering application.

N-Methylamino acids in peptide synthesis. VII. Studies on the enantiomeric purity of N-methylamino acids prepared by various procedures

1977 ◽  
Vol 55 (5) ◽  
pp. 916-921 ◽  
Author(s):  
S. T. Cheung ◽  
N. Leo Benoiton
Keyword(s):  
Amino Acid ◽  
Methyl Iodide ◽  
Peptide Synthesis ◽  
Liquid Ammonia ◽  
Silver Oxide ◽  
Sodium Hydride ◽  
Enantiomeric Purity ◽  
Amino Acid Analyzer ◽  
Pure Compounds ◽  
Optically Pure

The enantiomeric purity of N-methylamino acids and their derivatives obtained by various procedures has been examined by analysis with an amino-acid analyzer of the diastereomeric lysyl dipeptides formed by coupling them with a lysyl derivative. N-Benzyloxycarbonyl, and N-tert-butyloxycarbonyl,N-methylamino acids obtained by methylation of the parent derivative using sodium hydride and methyl iodide, and N-methylamino acids obtained by methylation of the p-toluenesulfonylamino acid followed by treatment with sodium in liquid ammonia, are optically pure. Compounds obtained by other procedures which include reductive alkylations or the use of silver oxide – methyl iodide are generally not optically pure.

scholarly journals The metabolic sequence by which some 4,4-dimethyl sterols are converted into cholesterol

1974 ◽  
Vol 144 (1) ◽  
pp. 59-68 ◽  
Author(s):  
Geoffrey F. Gibbons
Keyword(s):  
Microsomal Fraction ◽  
Soluble Fraction ◽  
Sterol Fraction ◽  
Methyl Groups ◽  
Methyl Group ◽  
Metabolic Sequence ◽  
Cholesterol Precursor ◽  
Fold Stimulation ◽  
Better Than ◽  
Stimulation Of

Cholest-8(14)-enol is the major radioactive component of the 4-di-demethyl sterol fraction biosynthesized from 4,4-dimethyl[2-3H2]cholest-8(14)-enol by rat liver microsomal fractions, and therefore the first steps in the biosynthesis of cholesterol from the latter compound probably involve removal of the 4-methyl groups. 4,4-Dimethylcholesta-8,14-dienol therefore is not an intermediate in this process, although its presence in the incubation medium at a concentration of 0.146mm almost completely inhibits the demethylation of 4,4-dimethyl[2-3H2]cholest-8(14)-enol. Nor is cholesta-8,14-dienol an intermediate in the conversion of cholest-8(14)-enol into cholest-7-enol and cholesterol. With 4,4-dimethyl[2-3H2]cholesta-8,14-dienol as the cholesterol precursor, 4,4-dimethylcholest-8(9)-enol becomes heavily labelled and there is very little radioactivity associated with cholesta-8,14-dienol.In this case, the most heavily labelled 4-di-demethyl sterols are cholest-7-enol and cholesterol with the former predominating. There is little or no radio-activity associated with cholest-8(14)-enol. A similar labelling pattern amongst the 4-di-demethyl sterols was observed with dihydro[14C]lanosterol as the precursor. The first step therefore in the synthesis of cholesterol from the 4,4-dimethyl[2-3H2]dienol is reduction of the Δ14(15) bond and not removal of the 4α-methyl group. Depending on the nature of the precursor, addition of the soluble fraction of the cell to the microsomal fraction resulted in a two- to four-fold stimulation of 4-di-demethyl sterol biosynthesis from the 4,4-dimethyl sterols studied. Under these conditions, 4,4-dimethylcholesta-8,14-dienol is the most efficient precursor of cholesterol and cholest-7-enol, and dihydrolanosterol is better than 4,4-dimethylcholest-8(14)-enol.

Tetraalkyldibismutane/Tetraalkyldibismutanes

1983 ◽  
Vol 38 (2) ◽  
pp. 125-129 ◽  
Author(s):  
Hans Joachim Breunig ◽  
Ditmar Müller
Keyword(s):  
Spectral Data ◽  
Nmr Spectra ◽  
Liquid Ammonia ◽  
Methyl Groups ◽  
H Nmr

Abstract The tetraalkyldibismutanes R2BiBiR2 (R = Et, Pr, iPr, Bu) were synthesized by reactions of 1,2-dibromoethane with sodium dialkylbismutides, which were produced by cleavage of the corresponding trialkylbismutanes with sodium in liquid ammonia. The dibismutanes were isolated in good yields as air sensitive red liquids. Spectral data of dibismutanes and some bismutanes are compared with data of their antimony analogues. 1H NMR spectra reveal, that the methylene protons in Et4Bi2 as well as the methyl groups in iPr4Bi2 are diastereotopic.

Unusual crystal structure ofN-substituted maleamic acid – very strong effect of intramolecular hydrogen bonds

2014 ◽  
Vol 70 (6) ◽  
pp. 942-947 ◽  
Author(s):  
Raju Francis ◽  
Pallepogu Raghavaiah ◽  
Kuruvilla Pius
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Amide Group ◽  
Intramolecular Hydrogen Bonds ◽  
X Ray ◽  
Planar Molecule ◽  
C And N ◽  
Maleamic Acid ◽  
Intramolecular Hydrogen

N-Carbamylmaleamic acid (malur) undergoes cyclodehydration under favourable conditions, as expected, to giveN-carbamyl maleimide.N-(Carboxymethyl) maleamic acid (malgly), however, does not undergo a similar cyclization reaction. Strong π bonding between the C and N of the amide group as well as two intramolecular hydrogen bonds makesmalglya planar molecule, as revealed by single-crystal X-ray studies.

Tricyclic psychotropic agents containing two chalcogen atoms in the central ring: Synthesis of 11-(dimethylaminoalkyl) derivatives of 11H-dibenzo[b,e]-1,4-dioxepin and 11H-dibenzo[b,e]-1,4-dithiepin

1982 ◽  
Vol 47 (1) ◽  
pp. 72-87 ◽  
Author(s):  
Karel Šindelář ◽  
Jiří Holubek ◽  
Miroslav Ryska ◽  
Emil Svátek ◽  
Antonín Dlabač ◽  
...  
Keyword(s):  
Liquid Ammonia ◽  
Sodium Hydride ◽  
Central Ring ◽  
Simultaneous Formation ◽  
Alternative Synthesis ◽  
Psychotropic Agents ◽  
Reserpine Hypothermia ◽  
The One ◽  
High Degree ◽  
Derivatives Of

1-[2-(2-Fluorophenoxy)phenyl]-4-dimethylaminobutanol (XI) was synthesized from 2-(2-fluorophenoxy)benzoic acid (VIII) in three steps and cyclized with sodium hydride in dimethylformamide to the title compound V. Reaction of 5-chloro-2-(methylthio)thiophenol (XIV) with sodium and liquid ammonia afforded benzene-1,2-dithiol (XIII) which was treated with 2-bromobenzyl bromide and gave 11H-dibenzo[b,e]-1,4-dithiepin (II). An alternative synthesis of compound II consisted in the cyclization of 2-(2-bromophenylthiomethyl)thiophenol (XVIII) and was accompanied by the simultaneous formation of 6H, 12H-dibenzo[b,f]-1,5-dithiocin (XIX) and thianthrene (XX). Reaction of compound II with n-butyllithium and the following treatment with dimethylaminoalkyl chlorides or with carbon dioxide resulted on the one hand in two further title compounds VI and VII, and in the carboxylic acid XXI on the other. 2-Chloro-11H-dibenzo[b,e]-1,4-dithiepin (XXII) was obtained by a further synthesis alternative using in the first step the cyclization of 2-(4-chloro-2-chloromethylphenylthio)thiophenol (XXV). Compound VI and VII showed a high degree of activity in the test of antagonization of reserpine hypothermia in mice.

A(1,3) interaction and conformational energy of axial–axial 1,3-dimethyl interaction

1968 ◽  
Vol 46 (17) ◽  
pp. 2821-2825 ◽  
Author(s):  
Y. L. Chow ◽  
C. J. Colón ◽  
J. N. S. Tam
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Free Energy ◽  
Type Strain ◽  
Conformational Energy ◽  
Methyl Groups ◽  
Kcal Mole ◽  
Magnetic Resonance Studies ◽  
Free Energy Of Activation ◽  
C And N ◽  
Derivatives Of

A(1,3) type strain was demonstrated directly from the nuclear magnetic resonance studies of the acyl and nitroso derivatives of 2-methylpiperidine (2 series) and 2,6-cis-dimethylpiperidine (1 series). In these two series, the bulky 2-methyl groups are forced to assume the axial conformation due to a severe A(1,3) interaction in the equatorial conformation. The free energy of activation (ΔG*) for the internal rotation around the N—C and N—N bonds in 1a–1g was determined. The comparison of these (ΔG*) values with those of the corresponding derivatives of dimethylamine indicates the decreases are in the range of 3.6–4.7 kcal/mole which is in fair agreement with the conformational energy of 1,3-diaxial CH3/CH3 interaction. An argument was presented to show that this interaction energy corresponds to the decrease of ΔG* in 1a-1g.

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