Metalation formamides

The synthesis from phthalimide derivatives, e.g., diimidophthalamide (or phthalimide) is usually carried out in a solvent such as formamide. Metal phthalocyanines may also he prepared using alkali metal salts or from metal-free phthalocyanine by boiling the latter in quinoline with metal salt. 

Polyacrylonitrile Dimethyl formamide Metal naphthanates and others... 

Incompatibilities and Reactivities Water, combustible materials, carbon disulfide, dimethyl-formamide, metals (except nickel lead) [Note Decomposes in water to hydrochloric phosphoric acids.] ... 

In addition to the processes mentioned above, there are also ongoing efforts to synthesize formamide direcdy from carbon dioxide [124-38-9J, hydrogen [1333-74-0] and ammonia [7664-41-7] (29—32). Catalysts that have been proposed are Group VIII transition-metal coordination compounds. Under moderate reaction conditions, ie, 100—180°C, 1—10 MPa (10—100 bar), turnovers of up to 1000 mole formamide per mole catalyst have been achieved. However, since expensive noble metal catalysts are needed, further work is required prior to the technical realization of an industrial process for formamide synthesis based on carbon dioxide. 

In unalloyed steel containers formamide discolors slowly during shipment and storage. Both copper and brass are also subject to corrosion, particularly in the presence of water. Lead is less readily attacked. Aluminum and stainless steel are resistant to attack by formamide and should be used for shipping and storage containers where the color of the product is important or when metallic impurities must be minimized. Formamide attacks natural mbber but not neoprene. As a result of the solvent action of formamide, most protective paints and finishes are unsatisfactory when in contact with formamide. Therefore, formamide is best shipped in containers made of stainless steel or in dmms made of, or coated with, polyethylene. Formamide supphed by BASF is packed in Lupolen dmms (230 kg) or Lupolen canisters (60 kg) both in continental Europe and overseas. 

Formamide has been alkylated with methanol ia the presence of a metal catalyst to give DMF (22). The alkylation reaction can also be catalyzed by tetralkylammonium salts (23). 

The Hg/dimethyl formamide (DMF) interface has been studied by capacitance measurements10,120,294,301,310 in the presence of various tetraalkylammonium and alkali metal perchlorates in the range of temperatures -15 to 40°C. The specific adsorption of (C2H5)4NC104 was found to be negligible.108,109 The properties of the inner layer were analyzed on the basis of a three-state model. The temperature coefficient of the inner-layer potential drop has been found to be negative at Easo, with a minimum at -5.5 fiC cm-2. Thus the entropy of formation of the interface has a maximum at this charge. These data cannot be described... 

British Biotech has described co-crystal structures of both BB-3497 and actinonin bound in the active site of E. coli PDF [24]. The metal centre (Ni ) in both complexes adopts a pentacoordinate geometry, bound by the two oxygen atoms of the hydroxamate along with Cys-90, His-132 and His-136. This coordination pattern is consistent with the mechanism of de-formylation proposed by Becker et al. [56] and Jain et al. [67], in which a pentacoordinated metal centre stabilises the transition state during hydrolysis of the formamide bond. When compared to the co-crystal structure of a substrate hydrolysis product, Met-Ala-Ser, it is clear that the side chains of these two inhibitors bind into the active site pockets similarly to the substrate [56]. 

Secondary amines, such as pyrrolidine, must be alkylated with care too polar a solvent leads to participation of a second nearby polymer-bound alkylant in the formation of a quaternary ammonium salt, along with the desired immobilized trialkyl amine. The exception, as seen above, is diisopropylamine, which refuses to displace tosylate even in the refluxing pure amine, or in hot dimethyl-formamide or other polar solvent, while metal diisopropylamide is notorious as a powerful non-nucleophilic base. However, carboxamide is not difficult to form from (carboxymethyl)polystyrene, again using toluenesulfonyl chloride as condensing agent this can then be reduced to (diisopropyl-ethylaminoethyl)polystyrene, which is of interest as a polymer-bound non-nucleophilic base. ... 

Transition metal complexes have been used in a number of reactions leading to the direct synthesis of pyridine derivatives from acyclic compounds and from other heterocycles. It is pertinent also to describe two methods that have been employed to prepare difficultly accessible 3-alkyl-, 3-formyl-, and 3-acylpyridines. By elaborating on reported194,195 procedures used in aromatic reactions, it is possible to convert 3-bromopyridines to products containing a 3-oxoalkyl function196 (Scheme 129). A minor problem in this simple catalytic process is caused by the formation in some cases of 2-substituted pyridines but this is minimized by using dimethyl-formamide as the solvent.196... 

Fig. 5. Limiting single ion mobilities vs. reciprocal of estimated crystallographic radii of alkali metal ions in several viscous solvents FM, formamide PC, propylene carbonate NMAC, Af-methylacetamide...

The formation of cyclopropane by reduction of 1,3-dibromopropane was discovered in 1887. Dissolving metals, in particular zinc dust in ethanol, were employed as an electron source [88], Electrochemical reduction in dimethyl-formamide at a mercury cathode has been found to give good yields of cyclopropane [89, 90], 1,3-dibromo, 1,3-diiodo and l-chloro-3-iodopropane all give greater than 90 % yield of cyclopropane, the other product being propene. 

An interesting appetite suppressant very distantly related to hexahydroamphetamines is somanta-dine (24). The reported synthesis starts with conversion of 1-adamantanecarboxylic acid (20) via the usual steps to the ester, reduction to the alcohol, transformation to the bromide (21), conversion of the latter to a Grignard reagent with magnesium metal, and transformation to tertiary alcohol 22 by reaction with acetone. Displacement to the formamide (23) and hydrolysis to the tertiary amine (24) completes the preparation of somantadine [6]. 

Also the selectivity of a separation can be increased by the addition of ions. Tjornelund and Hansen added magnesium ions to the buffer in order to separate tetracycline antibiotics in /V-methyl formamide as metal chelates... 

The conductivity of the electrolytes also plays a role in controlling nanotube array growth. Ethylene glycol containing 2% water and 0.35 % NH4F have a conductivity of 460 pS/cm which is much lower than the conductivity of the formamide based electrolytes (>2000 pS/cm) [27]. The total applied anodization voltage is the sum of the potential difference at the metal-oxide interface, the potential drop across the oxide, the potential difference at the oxide-electrolyte interface, and the potential drop across the... 

Metal-Nitrogen Compounds The cobalt catalyzed reaction of primary and secondary amines with carbon monoxide leads to the formation of formamide derivatives. Dimethylamine, for example, gives iV,i T-dimethvlformamide in 60% yield (90, 91). Very likely cobalt-nitrogen compounds are intermediates which undergo a CO insertion and then reduction. The following mechanism has been suggested for the reaction (90). 

As mentioned earlier, it has proven difficult to precipitate uniform metal (hydrous) oxides by direct mixing of solutions of metal salts and bases, especially of concentrated ones. Instead, it is possible to control the generation of hydroxide ions in situ, which can be achieved if certain organic compounds, such as formamide or urea, are slowly decomposed in aqueous solutions of metal salts. The rate of these processes depends on the pH, temperature, concentration of the reactants, and the presence or absence of metal complexing agents. In particular, precipitations caused by reactions in solutions of urea have been widely employed, although the products consist primarily of metal carbonates or basic metal carbonates. For this reason, this method is described in more detail in Chapter 7.1 of this volume. 

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