Formamide and Acetamide

The latter reaction yields actually Cu9 5S4 3 The reaction SnCU + 2H2S - SnS2i + 4HC1 

On the other hand halides of boron, aluminium and titanium are not solvolysed by the pure solvent. 

Copper acetate is converted into the sulphide, but cupric chloride remains unaffected in liquid hydrogen sulphide. The same is true for acetates of Mn(II), Co(II) and Cd(II), which give the sulphides in contrast to the behaviour of the chlorides 2 Mercuric acetate gives the sulphide rapidly, although its formation is slow when mercuric chloride is added to liquid hydrogen sulphide. 

Amphoteric behaviour has been found for the freshly prepared suspension of arsenic(III) sulphide, which may be dissolved by either acids or bases. 

The latter is again decomposed by admission of hydrogen chloride  

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The effects of the substituents on nitrogen on rotational barriers were discussed by Yoder and Gardner (34) for formamides and acetamides. The pertinent data, given in Table 5, suggest that the barriers to rotation of formamides are not affected by the bulkiness of the alkyl group on nitrogen, but such a conclusion... 

Effect of Substituents on Nitrogen on the Barrier to Rotation of Formamides and Acetamides (RCONR2) ... 

It is interesting to note that little work on this process has been conducted outside the laboratories of Phillips Petroleum Company and 3 M Company however, related studies on the fluorinations of formamide and acetamide in molten KH2F3 on amorphous carbon anodes at 120 °C have been reported by Tasaka and co-workers [57]. The amides were said to react with atomic fluorine produced on the (CxF)n [x > 2] film by discharge of fluoride ion, according to the scheme below. 

The enzyme urease catalyzes the hydrolysis of urea to form carbamate ion (equation 32). At pH 7.0 and 38 °C, the urease-catalyzed hydrolysis of urea is at least 1014 times as fast as the spontaneous hydrolysis of urea. Jack bean urease is a nickel(II) metalloenzyme502 with each of its six identical subunits containing one active site and two metal ions, and at least one of these nickel ions is implicated in the hydrolysis. It has been suggested503 that all substrates for urease (urea, N-hydroxyurea, 7V-methylurea, semicarbazide formamide and acetamide) are activated towards nucleophilic attack on carbon as a result of O-coordination to the active nickel(II) site as in (155). Nickel(II) ions have been found504 to promote the ethanolysis and hydrolysis of N-(2-pyridylmethyl)urea (Scheme 39) and this system is considered to be a useful model for the enzyme. 

Ottersen T (1975) On the structure of the peptide linkage. The structures of formamide and acetamide, at -165 °C and an ab-initio study of formamide, acetamide and N-methylform-amide. Acta Chem Scand A 29 939- 944... 

N.Q.R. The C1 n.q.r. spectra of cyclic 1,3,2-/i -diazaphosphorines correlate with parameters estimated by CNDO/2 calculations. The structures of the intermediates produced in the reactions of formamides and acetamides with phosphorus pentachloride and phosphoryl trichloride have been studied by n.q.r. spectroscopy. The stereochemistry of dichlorodiazadiphosphetane has been studied, and evidence on the polarity of radial chloride atoms in chlorophosphoranes discussed. ... 

Compared to the corresponding formamides and acetamides, the non-bonding interaction between the sulfur atom and the hydrogen atom of the methyl group attached to the nitrogen atom is important. Two rotamers of the a,p-un-saturated thioamides 6 and 7 are observed in NMR spectra, and their rotational barriers can be elucidated. The isomers 6, where the thiocarbonyl and benzyl groups are located in a cis position with respect to the C-N single bond. 

The complex formed with BF3-OEt2 and Epichlorohydrin in DMF acts as a catalyst for the Beckmann rearrangement of oximes. Cyclohexanone, acetaldehyde, and syw-benzaldehyde oximes are converted into e-caprolactam, a mixture of iV-methyl-formamide and acetamide, and Al-phenylacetamide, respectively. 

To explore this vital issue of cooperativity which reflects the nonadditive behavior of noncovalent interactions we have considered different model systems. In the first case we seek to check for presence of cooperativity among cation-n and hydrogen bonding [122] and cation-jt and jt-jt interactions [123]. In the second case we quantify cooperativity in systems with noncovalent interactions other than cation-jt interaction, for example in hydrogen bonded clusters of water, formamide and acetamide [110], clusters of jt-jt stacked benzene [124] etc. (Fig. 18.6). 

Formamide and acetamide are very useful solvents, which are highly associated in the pure liquid states due to hydrogen bonding. Recent reviews have covered their solvent properties in much detail . ... 

Table 21. Some Physical Properties of Formamide and Acetamide...

Due to their good donor properties formamide and acetamide dissolve many ionic compounds7 94,96 g ch as alkali halides, various salts of copper, zinc, cadmium, aluminium, tin, lead, nickel, mercury and other acceptor compounds, such as FeCls or SbCls. The high dielectric constants allow considerable dissociation of the compounds ionized in the solutions. 

Formamide and acetamide are levelling solvents for acids. Solvates of HCIO4, HNO3 and HCl have been isolated. The pK-values for various organic acids are tabulated in Table 22. 

S. Tsuzuki and K. Tanabe, /. Chem. Soc., Perkin Trans. 2, 1255 (1991). Basis Set and Electron Correlation Effects on die Internal Rotational Barrier Heights of Formamide and Acetamide. 

As noticed in Ref. (S 16), the nitrogen chemical shifts of methyl formamides and acetamides (D 18) correlate with the ionization potential of the highest occupied tt orbitals measured using photoelectron spectroscopy. Thus,... 

A check of the above result has been obtained by studying the effect of formamide and acetamide. These perturbants are known to increase the value of bulk dielectric constant of the solutions. ... 

Similar observations of stereoselective rearrangements of camphorato-ligands (fig. 2) have been observed upon adduct formation with formamide and acetamide... 

Amides derived from carboxylic acids (8-144) and the corresponding JV-substituted (8-145) and JV,JV-disubstituted amides (8-146) are polar compounds of low volatility, yet some of them may participate in the aroma of non-acidic foods. Commonly occurring compounds are mainly amides derived from formic and acetic acids. For example, beer contains hundredths to tenths mg/kg JV-methylformamide (8-145, R= H, RY CHj), JV-methylacetamide (8-145, R = rY CHj), JV ,Y-dimethylacetamide (8-146, R= R = R = CHj), JV -(2-methylbutyl)acetamide,whereR= CH3,R = CHjCH (CHj) CH2CH3, its isomer JV-(3-methylbutyl)acetamide, R = CH2 CH2CH(CHj)2 and JV -(2-phenylethyl)acetamide (8-147), which are produced by condensation of carboxylic acids with amines followed by decarboxylation (Figure 8.70). Many non-volatile JV-substituted formamides and acetamides are also produced in the Maillard reaction. Decarboxylation of asparagine catalysed by decarboxylases yields 3-aminopropionamide (8-148), which may become a precursor of acrylamide (see Section 12.2.2). 

Activation energies and temperature coefficients for soil amidase action against the three substrates were determined for a range of soils. Qio values for temperatures between 10 and 60°C averaged about 1.7 for formamide and acetamide, and 1.4 for propionamide. Amidase activities decreased with depth of soil profile, and were correlated with topsoil organic C and N contents, but not soil pH. 

Figure l-B-10. Semilog plot of the vapor pressures as a function of HT for a series of formamides and acetamides. 

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