Of formaldehyde and nitromethane

Fig. 7.6. The stereoselective template reaction of formaldehyde and nitromethane with primary amines coordinated in a cis-arrangement.

The condensation of nitromethane with formaldehyde is not typical of the general reaction since more than one molecule of formaldehyde tends to condense with one molecule of nitromethane even in the presence of a large excess of the latter. When equimolar quantities of formaldehyde and nitromethane are allowed to react the following approximate percentages of the three possible condensation products are obtained 1 ... 

Zard and coworkers have developed a synthesis of substituted dienes by reductive elimination of allylic nitroacetates (equation 33)66. Allylic nitroacetates can be prepared by condensation of nitromethane with the carbonyl compound followed by addition of formaldehyde and acetylation67. Reductive elimination can be carried out by employing either chromous acetate or samarium iodide. 

Henry reactions have been extensively exploited for the synthesis of nitrate ester explosives. The condensation of nitroalkanes with aldehydes, followed by esterification of the hydroxy groups with nitric acid, leads to a number of nitrate ester explosives (see Chapter 3). The two examples given above (166 and 167) are synthesized from the C-nitration of the polyols obtained from the condensation of formaldehyde with nitromethane and nitroethane respectively. 

Archibald, Coburn, and Hiskey at Los Alamos National Laboratory (LANL) have reported a synthesis of TNAZ (18) that gives an overall yield of 57 % and is suitable for large scale manufacture. Morton Thiokol in the US now manufactures TNAZ on a pilot plant scale via this route. This synthesis starts from readily available formaldehyde and nitromethane, which under base catalysis form tris(hydroxymethyl)nitromethane (35), and without isolation from... 

For the cyclization of dialdehydes, however, its utility seems limited. Being a nitromethane addition product, it can readily undergo retro-nitromethane addition with alkali to give formaldehyde and nitromethane. Thus, it is not surprising that reaction of glutaraldehyde with 2-nitroethanol under the usual conditions (i.e. 1 molar equivalent of sodium hydroxide in aqueous ethanol) should yield 2-nitrocyclohexane-1,3-diol 5), a nitromethane cyclization product With catal5dic amounts of sodium hydroxide (pH 8—9), however, 1-hydroxymethyl-l-nitro-cyclohexane-2-6-diol (80) can be isolated in yields of 24—29%... 

Nitroethanol prepared by the formaldehyde-nitromethane method should not be distilled without use of diphenyl ether as a heat-dispersing agent. The residue, consisting of di- and tricondensation products of formaldehyde with nitromethane, when hot and concentrated, and particularly when the vacuum is broken and air is let in on the hot distillation residue, is very likely to undergo a flash detonation, or at least a fume-off which may proceed with explosive violence. Use of diphenyl ether is a wise safety precaution in the distillation of 2-nitroethanol made by other methods as well. 

As an example, consider the reaction of the cobalt(m) complex of 7.8 with formaldehyde and nitromethane to give 7.9, the cobalt(m) complex of ligand 7.10 (Fig. 7-10). Notice that 7.8 is the same precursor that we needed for the synthesis of 7.7. In the new ligand, 7.10, the cap is formed from three molecules of formaldehyde and one of nitromethane, and the capping atom is now the carbon of the CN02 group derived from the nitromethane. 

It is also possible to make rather more dramatic changes in the structure of the preformed capping group, and 7.11, the cobalt(n) complex of a functionalised triaza macrocyclic ligand, reacts with formaldehyde and nitromethane to give 7.12. 

Perhaps the obvious extension of the methodology is to replace the ammonia nucleophile with the carbon nucleophile nitromethane. The reaction of [Co(en)3]3+ with formaldehyde and nitromethane in the presence of a base gives complex 7.15 (Fig. 7-14). Con-... 

Figure 7-14. The reaction of [Co(en)3]3 with formaldehyde and nitromethane gives cobalt(m) dinitrosarcophagine 7.15.

It is prepared by condensation of formaldehyde with nitromethane and by nitration of the nitroisobutylglycerine product under the same conditions as nitroglycerine. The nitration and stabilization procedures are very difficult because of decomposition reactions. 

This ester resembles its methyl homologue in possessing three modes of decomposition [131]. It also supports a self-decomposition flame, the multiple reaction zones of which are clearly separated at low pressures [122, 123, 125]. Temperature and composition profiles in the low-pressure decomposition flame have been measured [133]. The products include formaldehyde, acetaldehyde and ethanol with smaller amounts of methane and nitromethane. The activation energy derived from the variation of flame speed with final flame temperature was 38 kcal. mole", close to the dissociation energy of the RO—NO2 bond. The controlling reaction is believed to be unimolecular in its low pressure regime, and the rate coefficient calculated from the heat-release profile is... 

Sarcophaginates can also be prepared by template condensation of bis-triamine metal complexes with formaldehyde and nitromethane or ammonia. Macrotricyclic and macrotetracyclic complexes of different structures have simultaneously been formed [148, 149],... 

Treatment of [Co(tame)2] cation (where tame is 1,1,1-tris-(aminomethyl)ethane) in aqueous solution at pH 10.5 with formaldehyde and nitromethane gave mainly a macrotricyclic [Co(NOtrisartame)]3+ cation 1 in high yield (ca 50%), isolated as a... 

Condensation of [Co(tacn)2] bis-triaminate with formaldehyde and nitromethane led to an unusual clathrochelate complex with a stable carbanion, A tripodal cap from three formaldehyde and one nitromethane species formed on one octahedral face as expected by the conventional route. However, on another octahedral face, the capping process proceeded in an unusual way to stabilize a carbanion chelate and to methylate the remaining coordinated amino group ... 

When 1,3-propanediamine semiclathrochelates have been used instead of ethylenediamine derivatives, the encapsulation of large metal ions in low oxidation states predominated. For instance, the rhodium(III) sarcophaginate was obtained by template condensation of the corresponding semiclathrochelate with formaldehyde and nitromethane in a high yield [5j ... 

Using the appropriate template cations, macrocycles can be prepared from three different substrates. For example, the complex of copper with multi-dentate amines reacted with formaldehyde and nitromethane or diethyl ma-lonate (not shown) to form a peraza-crown (Comba et al., 1986 Lawrance and O Leary, 1987). The ratio of substrates can vary from 1 2 1 or 1 4 2 (amine formaldehyde activated carbon) depending on reaction conditions... 

In presence of Si02 Na0H the aldehydes, ketones and nitriles containing acidic hydrogen in 3-positions react with formaldehyde giving an unsaturated aldehyde, ketone or nitrile and a water molecule. The reaction of formaldehyde with nitromethane at the reaction temperature between 373-423K failed, giving only decomposition products. 

These syntheses depend on the reaction of a trismethylaminomethane with formaldehyde. Reaction of formaldehyde with nitromethane and ammo-dinm acetate in refluxing methanol leads to 7-nitro-l,3,5-triazaadainantane (IS) (Refs. 67-76). 

The template condensation of [Co( L869)2] + with formaldehyde and nitromethane in aqueous solution, followed by separation of the reaction mixture by ion-exchange chromatography, is represented in Schemes 4-7-4-9. Branched routes of successive transformations result in the formation of four main products, [Co(L872)]3+ to [Co(L875)] + [63, 64]. 

The works [158,185—188] investigated the effect of various parameters on the reaction onset temperature and the yield of the products. At pressures of 1 and 5 atm, the increase of the initial concentration of NO to 1% significantly, by 100 °C, decreased the temperature of the process, although the maximum obtainable conversion of methane was almost the same. However, the increase of the NO concentrations to 1.5% produced practically no effect. At these pressures, the selectivity of formation of oxygenates (methanol, formaldehyde, and nitromethane) reached a maximum at an NO concentration of 0.5%, so this concentration was adopted as optimal. The ethane formation selectivity decreased rapidly with increasing NO concentration, nearly to zero. Diluting the mixture with helium, at least up to 60%, had a moderate effect on the process. Even the CH4/O2 ratio, a key parameter of the... 

Methylene chloride is one of the more stable of the chlorinated hydrocarbon solvents. Its initial thermal degradation temperature is 120°C in dry air (1). This temperature decreases as the moisture content increases. The reaction produces mainly HCl with trace amounts of phosgene. Decomposition under these conditions can be inhibited by the addition of small quantities (0.0001—1.0%) of phenoHc compounds, eg, phenol, hydroquinone, -cresol, resorcinol, thymol, and 1-naphthol (2). Stabilization may also be effected by the addition of small amounts of amines (3) or a mixture of nitromethane and 1,4-dioxane. The latter diminishes attack on aluminum and inhibits kon-catalyzed reactions of methylene chloride (4). The addition of small amounts of epoxides can also inhibit aluminum reactions catalyzed by iron (5). On prolonged contact with water, methylene chloride hydrolyzes very slowly, forming HCl as the primary product. On prolonged heating with water in a sealed vessel at 140—170°C, methylene chloride yields formaldehyde and hydrochloric acid as shown by the following equation (6). 

The addition of propylene also led to the increase of NO removal efficiency in a pulsed DBD in a mixture containing N2, 02, NO and 500 ppm C3H6 [30,35], Consequently, the energy cost for NO oxidation decreased from 42 to 25 eV/NO molecule [30], The authors also observed an increase in NO removal up to 30%. The major reaction products detected were carbon oxides, formaldehyde, acetaldehyde, propylene oxide, formic acid, ethyl acetate, methyl nitrate and nitromethane. 

Nitrogen triiodide a-Nitroguanidine Nitromethane Acids, bromine, chlorine, hydrogen sulfide, ozone Complex salts of mercury and silver Acids, alkylmetal halides, hydroxides, hydrocarbons, organic amines, formaldehyde, nitric acid, perchlorates... 

The reaction between formaldehyde and compounds containing acidic protons is probably the most important route to polyols. Some of these polyols have been 0-nitrated and used as practical explosives. The condensation of nitromethane and nitroethane with excess formaldehyde in the presence of potassium hydrogen carbonate yields tris(hydroxymethyl)nitromethane (58) and l,l-bis(hydroxymethyl)nitroethane (60) respectively. The nitration of (58) and (60) with either absolute nitric acid or mixed acid gives the secondary high explosives, (59) and (61) respectively. 

The Mannich condensation between nitromethane, formaldehyde and t-butylamine, followed by nitrolysis of the resulting product (101), has been used to synthesize 1,3,5-trinitro-hexahydropyrimidine (102) (TNHP) treatment of the latter with formaldehyde in a Henry type methylolation, followed by 0-nitration with nitric acid, yields the nitrate ester (103). ... 

Beyer and coworkers later extended these reactions to platinum clusters Ptn and have demonstrated that similar reaction sequences for the oxidation of carbon monoxide can occur with larger clusters [70]. In addition, they were able to demonstrate poisoning effects as a function of surface coverage and cluster size. A related sequence for Pt anions was proposed by Shi and Ervin who employed molecular oxygen rather than N2O as the oxidant [71]. Further, the group of Bohme has screened the mononuclear cations of almost the entire transition metal block for this particular kind of oxidation catalysis [72,73]. Another catalytic system has been proposed by Waters et al. in which a dimolybdate anion cluster brings about the oxidation of methanol to formaldehyde with nitromethane, however, a rather unusual terminal oxidant was employed [74]. 

Methylamine occurs in herring brine 2 in crude methyl alcohol from wood distillation,3 and in the products obtained by the dry distillation of beet molasses residues.4 It has been prepared synthetically by the action of alkali on methyl cyanate or iso-cyanurate 5 by the action of ammonia on methyl iodide,6 methyl chloride,7 methyl nitrate,8 or dimethyl sulfate 9 by the action of methyl alcohol on ammonium chloride,10 on the addition compound between zinc chloride and ammonia,11 or on phos-pham 12 by the action of bromine and alkali on acetamide 13 by the action of sodamide on methyl iodide 14 by the reduction of chloropicrin,15 of hydrocyanic or of ferrocyanic acid,16 of hexamethylenetetramine,17 of nitromethane,18 or of methyl nitrite 19 by the action of formaldehyde on ammonium chloride.20... 

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