Formaldehyde—ammonia interaction

Interaction of dime thy loin icramide with formaldehyde-ammonia gave an 83% yield (on formaldehyde basis) of DPT, mp 206—08°. 

The trimethylamine may be generated by the action of alkali on trimethylamine hydrochloride and dissolved in acetone. The submitter prepared trimethylamine by the method of Som-melet and Ferrand and obtained a 65% yield by the interaction of ammonia, formaldehyde, and formic acid. The checkers found that a commercial 25% solution of trimethylamine in methanol (210 ml.) gave the same yields as the acetone solution. 

The molecular (161) and dissociative (162, 163) adsorption of NH3 on MgO was investigated by IR and UV-VIS spectroscopies (257). The results show that a small fraction of ammonia undergoes heterolytic dissociation on adjacent low-coordinated Mg2+ and O2 ions to form NH2 and OH- groups. The reaction of CO with the NH2 and OH has been characterized by IR emission spectroscopy (164). Formaldehyde and formates are formed first they react to give isocyanate derivatives, and decomposition at high temperatures yields simple (NCO) ions (164). Garrone et al. (165) reported the interaction of N2O with irreversibly preadsorbed ammonia to yield surface azid (Nj) species. The interaction of O2 with preadsorbed NH3 on MgO was described by Martra et al. (166), who used IR spectroscopy the oxidized species Nj, N3, NO, NO2, and NO3 were detected. 

Since the suggestion of the sequential QM/MM hybrid method, Canuto, Coutinho and co-authors have applied this method with success in the study of several systems and properties shift of the electronic absorption spectrum of benzene [42], pyrimidine [51] and (3-carotene [47] in several solvents shift of the ortho-betaine in water [52] shift of the electronic absorption and emission spectrum of formaldehyde in water [53] and acetone in water [54] hydrogen interaction energy of pyridine [46] and guanine-cytosine in water [55] differential solvation of phenol and phenoxy radical in different solvents [56,57] hydrated electron [58] dipole polarizability of F in water [59] tautomeric equilibrium of 2-mercaptopyridine in water [60] NMR chemical shifts in liquid water [61] electron affinity and ionization potential of liquid water [62] and liquid ammonia [35] dipole polarizability of atomic liquids [63] etc. 

When nitromethane is used as the capping agent instead of ammonia, either the interaction of the nitromethane anion with coordinated ethyleneimine or the addition of nitroethylene to deprotonated coordinated amine yields an intermediate nitroethyl complex. Nitroethylene is formed by a base-catalyzed condensation of nitromethane and formaldehyde. The experimental data suggest that the mechanism of formation of the nitroethyl complex via coordinated imine by Scheme 106 is favoured [101]. 

In attempting to increase the yields of formaldehyde by stabilizing it as hexamethylene-tetramine through interaction with ammonia added to the reaction mixture, these workers found that the effect on formaldehyde yield was insignificant. The yield of formic acid, however, was increased to an amount equal to that of the formaldehyde. The lack of methanol production in these experiments is attributed to the greater ease with which methanol is oxidized compared with methane. Methanol is probably formed as a first step and has but a momentary existence under the experimental conditions. 

Pyridine was first isolated, like pyrrole, from bone pyrolysates the name is constrncted from the Greek for fire, pyr , and the suffix idine , which was at the time being used for all aromatic bases - phenetidine, toluidine, etc. Pyridine and its simple alkyl derivatives were for a long time produced by isolation from coal tar, in which they occur in quantity. In recent years this source has been displaced by synthetic processes pyridine itself, for example, can be produced on a commercial scale in 60-70% yields by the gas-phase high-temperatnre interaction of crotonaldehyde, formaldehyde, steam, air and ammonia over a silica-alumina catalyst. Processes for the manufacture of alkyl-pyridines involve reaction of acetylenes and nitriles over a cobalt catalyst. 

Its presence in roasting mixtures of serine and/or threonine with an equimolar amount of sucrose was observed by Baltes and Bochmann (1987d). This oxazole results, probably, from an interaction between 2,3-pentanedione, formaldehyde and ammonia present in the roasting coffee medium. 

Its origin in roasted coffee can be explained by an interaction between 2,3-pentanedione, formaldehyde and ammonia. 

Vinylamine addition to formaldehyde was studied by Sevin, Maddaluno and Agami, using the minimal STO-3G basis, improved by a configuration interaction step involving all single and double excitations from the n and n occupied orbitals of the reactants to their two lowest vacant orbitals [134]. The authors conclude that formation of a zwitterionic intermediate is not likely in the absence of protic solvation. In analogy to the reactions of water and ammonia with formaldehyde, such a path is very endothermic, and no activation energy barrier is encountered except when the conformation about the incipient bond is eclipsed. For a concerted path. 

This synthesis was subsequently shortened (67) interaction of the diazo ketone, XLII, with acetic acid gave an acetate (XLVIII), hydrolyzed to the keto alcohol (XLIX), treatment of which with copper acetate, ammonia, and formaldehyde gave d-pilocarpidine (XLVI). This method has also been applied to the synthesis of 2-alkyl derivatives of pilocarpine. 

Volatile compounds were found to penetrate into polyetherimide resins. Chemical moieties such as bromine, iodine, hydrofluoric acid, hydrochloric acid, hydrobromic acid, ammonia, hydrazine, triethylamine, formaldehyde, formic or acetic acid, trifluoroacetic acid, and nitric acid were examined. The use of these chemical impregnators to augment the mechanical component was investigated. In addition to being volatile, candidate materials had to either etch the polyetherimide surface or interact with subsequent species to etch the... 

Acetaldehyde can undergo various interactions with butanedione, hydrogen sulfide, methanethiol and ammonia to give various aliphatic sulfur compounds, thiazoles, thiadiazines and dithiazines as shown in Fig. 1. Compounds identified in YEs are indicated by ( ) (29). The involvement of alternative aldehydes, such as formaldehyde in place of acetaldehyde or mixtures of aldehydes, will lead to the corresponding homologues, some of which have also been reported in YEs. Another aldehyde, 3-methylbutanal, reacts with hydrogen sulfide and methanethiol to give the hemidithioacetal, l-methylthio-3-methyl-l-butanethiol which has been reported in YEs (14). Compounds of this class possess characterisitic meaty aromas with an onion note (14). 

This increase in Tg is higher than that expected if only phenol and formaldehyde were used, and is a result of the hydrogen-bonding interaction between the backbone amine units and the phenolic hydroxyls. Taking advantage of this effect, hexa and ammonia have been frequently used to produce solid, grindable, and water-insoluble resoles for molding compoimds. 

Quite astonishing structural determinations can be obtained in the hands of highly skilled workers. For example, Yufit and Howard have recently reported the X-ray structures of novel chloroform cocrystals with methanol, cyclopentanone, cyclohexanone, diethylamine, and dimethylformamide at low temperatures. Further, the Boese group have determined the structures of many acetylene cocrystals and have reviewed this important work recently. Examples are the compounds of acetylene with benzene (1 1), formaldehyde (1 1), acetonitrile (2 1) (Fignre 27), and ammonia (1 1). These striking successes indicate the potential for future studies on unstable and low-melting clathrate compounds that may involve only very weak interactions. 

Formaldehyde and ammonia are not exactly a typical case for a carbonyl-amine interaction, but this result certainly suggests that whatever Lewis bonding occurs in more typical cases wiU likely be pretty small. The more typical case is shown in Figure 9.9, which is for the interaction of acetone with trimethylamine. 

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