Methylation formaldehyde

Fluorotrichloromethane, see Trichlorofluoromethane Fly-die, see Dichlorvos Fly fighter, see Dichlorvos FMC 5462, see a-Endosulfan, p-Endosulfan FMC 10242, see Carbofuran Foliclol, see Parathion Folidol, see Parathion Folidol E 605, see Parathion Folidol E E 605, see Parathion Folidol oil, see Parathion Forane, see 1,1,2-Trichlorotrifluoroethane Foredex 75, see 2,4-D Forlin, see Lindane Formal, see Malathion, Methylal Formaldehyde bis(p-chloroethylacetal), see Bis(2-chloroethoxy) methane Formaldehyde dimethylacetal, see Methylal Formalin, see Formaldehyde Formalin 40, see Formaldehyde Formalith, see Formaldehyde Formic acid, ethyl ester, see Ethyl formate Formic acid, methyl ester, see Methyl formate Formic aldehyde, see Formaldehyde Formic ether, see Ethyl formate Formira, see Formic acid Formisoton, see Formic acid Formol, see Formaldehyde Formosa camphor, see Camphor Formula 40, see 2,4-D... 

Symnyms Ethanal acetic aldehyde ethyl-aldehyde methyl formaldehyde... 

Acetone reacted with acetylene in methylal (formaldehyde dimethyl acetal) at 5°, in the presence of a 3 7 mixture of NaOH pellets and powdered KOH 2,5-dimethyl-3-hexyne-2,5-diol (startg. m. f. 159). Y 90-95%.—At lower temp., acetylene adds only 1 mole of acetone to give 3-methyl-l-butyn-3-ol. (H. Richet, A. ch. [12] 3, 317 (1948).)... 

Methylal (formaldehyde dimethyl acetal) was obtained by Fischer and Giebe910 as follows 1 % methanolic hydrochloric acid (2.5 parts) is poured over finely powdered paraformaldehyde (1 part), and the mixture is warmed at 100° for 12-15 h. All the solid dissolves and the smell of formaldehyde soon disappears. The mixture is neutralized with sodium hydroxide solution and fractionated through an efficient column. This gives methylal, b.p. 41-42°, in 80% yield. 

Weizmann, Bergmann, and Sulzbacher132 prepared this 2-(trichloromethyl)-2-propanol according to the following procedure Freshly molten and powdered potassium hydroxide (102 g) was added to anhydrous methylal (formaldehyde dimethyl acetal 500 ml) at —4° a mixture of chloroform (215 g) and acetone (116 g) was next run in at the same temperature during 2 h. The mixture was stirred for a further 2 h, after which it was poured into dilute sulfuric acid and ice. The upper layer was separated and the aqueous layer was shaken with methylal. The solvent was distilled off from the united organic layers, and the crystalline residue was distilled in steam, affording the product as needles, m.p. 91°. 

Gabunine (A -demethylconodurine) mp 244°-246° [aJu —105° in CHCI3) was converted into conodurine by reductive methylation (formaldehyde-hydrogen-palladium charcoal) in 50% aqueous dioxane 9). 

Formaldehyde dimethylacetal. See Methylal Formaldehyde ethyl cyclododecyl acetal CAS 58567-11-6 EINECS/ELINCS 261-332-1 Synonyms Boisambrene forte Cyclododecane, (ethoxymethoxy)- (Ethoxymethoxy) cyclododecane Formaldehyde cyclododecyl ethyl acetal... 

Formaldehyde methyl ketal. See Methylal Formaldehyde-naphthalenesulfonic acid copolymer. See Naphthalene-formaldehyde sulfonate... 

Methylal (Formaldehyde dimeth acetal, dimethoxymethane, methane dimethi ether)... 

Methyl-2-pentanoi b.p. 132 C, a solvent for nitrocellulose, urea-formaldehyde and alkyd resins. It is also used in ore flotation. 

The Formaldehyde-Formic Acid Method, This method applies to primary and secondary amines, which when boiled with a formalin-formic acid mixture undergo complete methylation to the corresponding tertiary amine. This method has the advantage over the dimethyl sulphate method in that quaternary salts clearly cannot be formed. 

Formaldehyde is a gas, b.p. — 21°, and is usually prepared by the dehydrogenation of methyl alcohol m the presence of heated copper or silver. By admitting air with the methyl alcohol vapour, part of the hydrogen is oxidised to give the heat necessary for the reaction ... 

Formaldehyde is a gas, b.p. — 21°, and cannot obviously be stored as such moreover, it polymerises readily in the liquid and the gaseous state. The commercial preparation, formalin, is an aqueous solution containing 35-40 per cent, of formaldehyde and some methyl alcohol. The preparation of a solution of formaldehyde may be demonstrated by the following experiment. 

The formaldehyde may be replaced by methylal CHjlOCH,), or by chloro-methyl ether CHjOCHjCl, produced from paraformaldehyde, hydrogen chloride and methyl alcohol ... 

The p-substituted amino ketones can be reduced readily to the more stable P-dialkylamino alcohols, many of which are useful local anaesthetics. Thus the local anaesthetic Tutocaine is made from the Mannich base derived from formaldehyde, methyl ethyl ketone and dimethylamine, followed by reduction and conversion into the p-aminobenzoate ... 

The conventional electrochemical reduction of carbon dioxide tends to give formic acid as the major product, which can be obtained with a 90% current efficiency using, for example, indium, tin, or mercury cathodes. Being able to convert CO2 initially to formates or formaldehyde is in itself significant. In our direct oxidation liquid feed fuel cell, varied oxygenates such as formaldehyde, formic acid and methyl formate, dimethoxymethane, trimethoxymethane, trioxane, and dimethyl carbonate are all useful fuels. At the same time, they can also be readily reduced further to methyl alcohol by varied chemical or enzymatic processes. 

Only reaction 1 provides a direct pathway to this chiral molecule the intermediate 2-methyl-butanal may be silylated and reacted with formaldehyde in the presence of the boronated tartaric ester described on page 61. The enantiomeric excess may, however, be low. 

Alkynyl)oxiranes also react with carbon nucleophiles to afford furan derivatives. Furanes of different types are obtained depending on the structure of the substrates. 7-Methyl-2-ethynyloxirane (95) reacts with acetoacetate to give the furan 97 by the elimination of formaldehyde from the cyclized product 96. The hydroxy ester of the alkylidenefuran 98 and the corresponding lactone 99 are obtained by the reaction of i-methyl-2-(2-propynyI)oxirane[40, 42]. 

Under appropriate conditions 2-amino-4-alkylthiazoles are alkylated in the 5-position 2-acetylamino-4-methylthiazole reacts with dimethyl-amine and formaldehyde to afford the corresponding Mannich base (113) (372). 2-Amino-4-methyl-thiazole is alkylated in the 5-position by heat-... 

Figure 5.1 Principal inertial axes of (a) hydrogen cyanide, (b) methyl iodide, (c) benzene, (d) methane, (e) sulphur hexafluoride, (f) formaldehyde, (g) s-lraws-acrolein and (h) pyrazine...

Under acidic conditions, furfuryl alcohol polymerizes to black polymers, which eventually become crosslinked and insoluble in the reaction medium. The reaction can be very violent and extreme care must be taken when furfuryl alcohol is mixed with any strong Lewis acid or Brn nstad acid. Copolymer resins are formed with phenoHc compounds, formaldehyde and/or other aldehydes. In dilute aqueous acid, the predominant reaction is a ring opening hydrolysis to form levulinic acid [123-76-2] (52). In acidic alcohoHc media, levulinic esters are formed. The mechanism for this unusual reaction in which the hydroxymethyl group of furfuryl alcohol is converted to the terminal methyl group of levulinic acid has recendy been elucidated (53). 

Pyronines. Pyronines are diphenylmethane derivatives synthesized by the condensation of y -dialkylarninophenols with formaldehyde, followed by oxidation of tiie xantiiene detivative (12) to the coiiesponding xanthydiol (13) which in the presence of acid forms the dye (14). If R is methyl, the dye produced is... 

Acetylation of acetaldehyde to ethyUdene diacetate [542-10-9], a precursor of vinyl acetate, has long been known (7), but the condensation of formaldehyde [50-00-0] and acetic acid vapors to furnish acryflc acid [97-10-7] is more recent (30). These reactions consume relatively more energy than other routes for manufacturing vinyl acetate or acryflc acid, and thus are not likely to be further developed. Vapor-phase methanol—methyl acetate oxidation using simultaneous condensation to yield methyl acrylate is still being developed (28). A vanadium—titania phosphate catalyst is employed in that process. 

Anhydrous, monomeric formaldehyde is not available commercially. The pure, dry gas is relatively stable at 80—100°C but slowly polymerizes at lower temperatures. Traces of polar impurities such as acids, alkahes, and water greatly accelerate the polymerization. When Hquid formaldehyde is warmed to room temperature in a sealed ampul, it polymerizes rapidly with evolution of heat (63 kj /mol or 15.05 kcal/mol). Uncatalyzed decomposition is very slow below 300°C extrapolation of kinetic data (32) to 400°C indicates that the rate of decomposition is ca 0.44%/min at 101 kPa (1 atm). The main products ate CO and H2. Metals such as platinum (33), copper (34), and chromia and alumina (35) also catalyze the formation of methanol, methyl formate, formic acid, carbon dioxide, and methane. Trace levels of formaldehyde found in urban atmospheres are readily photo-oxidized to carbon dioxide the half-life ranges from 35—50 minutes (36). 

Formaldehyde is readily reduced to methanol by hydrogen over many metal and metal oxide catalysts. It is oxidized to formic acid or carbon dioxide and water. The Cannizzaro reaction gives formic acid and methanol. Similarly, a vapor-phase Tischenko reaction is catalyzed by copper (34) and boric acid (38) to produce methyl formate ... 

Between 50 and 60% of the formaldehyde is formed by the exothermic reaction (eq. 23) and the remainder by endothermic reaction (eq. 24) with the net result of a reaction exotherm. Carbon monoxide and dioxide, methyl formate, and formic acid are by-products. In addition, there are also physical losses, hquid-phase reactions, and small quantities of methanol in the product, resulting in an overall plant yield of 86—90% (based on methanol). 

Methylenebis(4-phenyl isocyanate). This compound is also known as methyl diisocyanate [101-68-8] (MDI) and is produced by the condensation of aniline and formaldehyde with subsequent phosgenation. Its principal end use is rigid urethane foams other end uses include elastic fibers and elastomers. Total formaldehyde use is 5% of production (115). 

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