Acetic anhydride formaldehyde

Methyl isocyanate Acetic anhydride Formaldehyde solution Water... 

Acetic anhydride Formaldehyde Nickel plating solutions... 

Acetic anhydride is a useful solvent in certain nitrations, acetylation of amines and organosulfur compounds for mbber processing, and in pesticides. Though acetic acid is unexceptional as a fungicide, small percentages of anhydride in acetic acid, or in cold water solutions are powerful fungicides and bactericides. There are no reports of this appHcation in commerce. It is possible that anhydride may replace formaldehyde for certain mycocidal apphcations. 

Uses ndReactions. The Prins reaction of 3-carene with formaldehyde in acetic acid gives mainly 2-carene-4-methanol acetate, which when saponified produces the 2-carene-4-methanol, both of which are commercial products of modest usage (60). 3-Carene (28) also reacts with acetic anhydride with a catalyst (ZnCl2) to give 4-acetyl-2-carene (29) (61), which is also a commercial product. Although 3-carene does not polymerize to produce terpene resins, copolymerization with phenol has been successfully commercialized by DRT in France (62). 

The Prins reaction with formaldehyde, acetic acid, acetic anhydride, and camphene gives the useful alcohol, 8-acetoxymethyl camphene, which has a patchouli-like odor (83). Oxidation of the alcohol to the corresponding aldehyde also gives a useful iatermediate compound, which is used to synthesize the sandalwood compound dihydo- P-santalol. 

Acetals. Acetal resins (qv) are polymers of formaldehyde and are usually called polyoxymethylene [9002-81-7]. Acetal homopolymer was developed at Du Pont (8). The commercial development of acetal resins required a pure monomer. The monomer is rigorously purified to remove water, formic acid, metals, and methanol, which act as chain-transfer or reaction-terminating agents. The purified formaldehyde is polymerized to form the acetal homopolymer the polymer end groups are stabilized by reaction with acetic anhydride to form acetate end groups (9). 

Cyanuric acid readily dissolves in aqueous formaldehyde forming tris(hydroxymethyl)isocyanurate [10471-40-6] (THMIC) which can be isolated by evaporation (11). THMIC in turn reacts with acetic anhydride to yield tris(acetoxymethyl)isocyanurate [54635-07-3], either thionyl chloride or phosphoms pentachloride to give tris(chloromethyl)isocyanurate [63579-00-0], and phenyl isocyanate in pyridine to yield tris(A/-phenylcarbamoxymethyl) isocyanurate [21253-39-4] in 87% yield (65). Reaction of CA with paraformaldehyde and 2,6-dicyclohexylphenol yields... 

Processing and storage equipment for many chemicals, including acetaldehyde, formaldehyde, nylon salt, methyl methacrylate, carbon tetrachloride, glycerol, triacetin, proprionic acid, acetic acid and acetic anhydride, is manufactured from aluminium alloys, primarily because of their excellent corrosion resistance. 

It is made by the nitration of hexamine (hexamethylenetetramine), itself prepared from formaldehyde and ammonia. Hexamine was originally nitrated with a large excess of concentrated nitric acid at temperatures below 30°C and the product recovered by adding the reaction liquor to an excess of chilled water. Later the yield was improved by adding ammonium nitrate to the reaction as this reacts with the liberated formaldehyde. A much-used process converts the hexamine first to its dinitrate, which is then reacted with ammonium nitrate, nitric acid and acetic anhydride (the last reagent being re-formed from the product by use... 

Synthesis of isomeric chiral protected (63 )-6-amino-hexahydro-2,7-dioxopyrazolo[l,2- ]pyrazole-l-carboxylic acid 280 is shown in Scheme 36. Crude vinyl phosphonate 275, obtained by treatment of diethyl allyloxycarbonylmethyl-phosphonate with acetic anhydride and tetramethyl diaminomethane as a formaldehyde equivalent, was used in the Michael addition to chiral 4-(f-butoxycarbonylamino)pyrazolidin-3-one 272. The Michael addition is run in dichloro-methane followed by addition of f-butyl oxalyl chloride and 2 equiv of Huning s base in the same pot to provide 276 in 58% yield. The allyl ester is deprotected using palladium catalysis to give the corresponding acid 277, which is... 

Symmetrical piperazines 364 have been obtained from the corresponding 4,5-dihydrazinofurazano[3,4- ]pyraz ne 363 in good yield on reaction with acetic anhydride in the presence of a Lewis acid (Equation 98) <1999CHE499>. When formaldehyde was used, the yield was slightly reduced at 76%. Acid chlorides can also be used in this reaction although the yield drops to 23% when trichloroacetyl chloride is used. 

Dimethyl-3,5-dimethyl-l//,3//-pyrrolo[l,2-r ][l,3]thiazole-6,7-dicarboxylate 399 (R = H) was prepared from cysteine 396 using the method developed of Padwa et al. <1989JOC644>. The thiazolidine carboxylic acid 397 (R = H), obtained by reaction of the cysteine with formaldehyde, was heated in the presence of acetic anhydride and DMAD to give the sulfide 399 by dipolar cycloaddition of the acetylene to the intermediate dipole 398 (Scheme 59) <2002J(P1)1795>. 

Formation of the partially saturated nitro derivatives 60 and 61 was reported by a Russian team <1994KGS1129>. The two products were obtained under fairly complicated reaction conditions when aminotetrazole 42 was first treated with potassium amidosulfonate and formaldehyde at pH = 4 followed by addition of nitric acid, methylamine, and acetic anhydride, product 60 was obtained in 24% yield. The same reaction, however, carried out at pH = 6 gave rise to formation of the acetoxy compound 61 in 21% yield. 

Korai (2001) also considered the importance of density profile of composites made from acetylated fibres in determining mechanical properties. Fibres of yellow cedar were acetylated with vapour-phase acetic anhydride and fibreboards were made from these, bonded with melamine formaldehyde resin. The results from this study indicated that bonding between fibres was the most important property determining mechanical properties. 

The production of moisture resistant particleboard by treatment with a maleic anhydride -glycerol mixture and using phenol formaldehyde as the matrix material has been investigated (Fujimoto etal., 1987). Boards prepared from modified wood showed considerable improvements in modulus of elasticity and internal bond strength when compared to control boards. Composites made from aspen fibres modified with SA, MA or acetic anhydride using phenol-formaldehyde (PF) or polypropylene as binder have also been studied (Clemons etal., 1992 Rowell etal., 1993b). The reaction of wood with MA was found to proceed at a slower rate than with SA. The volume increase due to modification... 

Once methanol is produced, it can be converted to an extensive range of materials. The following reactions illustrate some of the chemicals of major importance that can be made from methanol. Among these are dimethyl ether, acetic acid, methyl acetate, acetic anhydride, vinyl acetate, formaldehyde, and methyl tertiarybutyl ether (MTBE). 

Chapman studied the nitrolysis of symmetrical methylenediamines. The nitrolysis of N, N, N, M-tetramethylmethylenediamine with nitric acid-acetic anhydride-ammonium nitrate mixtures gives both dimethylnitramine and RDX the latter probably arises from the nitroT ysis of hexamine formed from the reaction of ammonium nitrate and formaldehyde released from the hydrolysis of the methylenediamine. The same reaction with some morpholine-based methylenediamines (105) allows the synthesis of l,3,5-trinitro-l,3,5-triazacycloalkanes (106). 

Variations in the conditions used for the nitrolysis of hexamine have a profound effect on the nature and distribution of isolated products, including the ratio of RDX to HMX. It has been shown that lower reaction acidity and a reduction in the amount of ammonium nitrate used in the Bachmann process increases the amount of HMX formed at the expense of Bachmann and co-workers ° were able to tailor the conditions of hexamine nitrolysis to obtain an 82 % yield of a mixture containing 73 % HMX and 23 % RDX. Continued efforts to provide a method for the industrial synthesis of HMX led Castorina and co-workers to describe a procedure which produces a 90 % yield of a product containing 85 % HMX and 15 % RDX. This procedure conducts nitrolysis at a constant reaction temperature of 44 °C and treats hexamine, in the presence of a trace amount of paraformaldehyde, with a mixture of acetic acid, acetic anhydride, ammonium nitrate and nitric acid. Bratia and co-workers ° used a three stage aging process and a boron trifluoride catalyst to obtain a similar result. A procedure reported by Picard " uses formaldehyde as a catalyst and produces a 95 % yield of a product containing 90 % HMX and 10 % RDX. 

However, the yield of DPT from such reactions is often poor (15-25 %). DPT has also been synthesized from the reaction of hexamine dinitrate with acetic anhydride or cold 90 % aqueous sulphuric acid. Both methods under optimum conditions give yields of DPT of approximately 31 The reaction of nitramine (NH2NO2) with aqueous formaldehyde, followed by neutralization of the reaction mixture with ammonia to pH 5.5-6.5, gives DPT in 73 % yield based on the nitramine starting material. This last reaction presumably involves the formation of dimethylolnitramine as an intermediate (Section 5.15.4.2). 

Dagley and co-workers reported the synthesis of 2-nitrimino-5-nitrohexahydro-1,3,5-triazine (100) from the Mannich condensation of nitroguanidine (98), formaldehyde and t-butylamine, followed by nitrolysis of the t-butyl group of the resulting product, 2-nitrimino-5-fert-butylhexahydro-l,3,5-triazine (99). The triazine (100) has also been synthesized from the reaction of nitroguanidine and hexamine in aqueous hydrochloric acid, followed by nitration of the resulting product (97) with a solution of nitric acid in acetic anhydride. ... 

Commercial polymers of formaldehyde are also produced using cationic polymerization. The polymer is produced by ring opening of trioxane. Since the polyacetal, POM, is not thermally stable, the hydroxyl groups are esterified (capped) by acetic anhydride (structure 5.22). These polymers are also called poly(methylene oxides). The commercial polymer is a... 

The industrial synthesis of polyformaldehyde [poly(oxymethylene)] occurs by anionic polymerization of formaldehyde in suspension. For this the purification and handling of monomeric formaldehyde is of special importance since it tends to form solid paraformaldehyde. After the polymerization the semiacetal end groups have to be protected in order to avoid thermal depolymerization (Example 5-13). This is achieved by esterfication with acetic anhydride (see Example 5-7). As in the case of trioxane copolymers (see Sect. 3.2.3.2) the homopolymers of formaldehyde find application as engineering plastics. 

Methanol is an ideal starting material for the synthesis of many chemicals. It is the most important feedstock for the large-scale commercial production of acetic acid and formaldehyde. Additionally, a variety of other chemicals such as methyl esters, methyl halides and methyl ethers can be produced from it. Tenessee-Eastman s recent pioneering commercialization of a coal-based process for acetic anhydride production illustrates the growing importance of methanol as chemical feedstock. 

Trinitro-l 3 5-triazacyclohexane (I) has been synthesised from (V), acetic anhydride, and formaldehyde... 

Formaldehyde, Methylnitramine, Methylene chloride, Magenesium sulfate. Sulfuric acid. Chloroform, Hexane Nitric acid. Diethanolamine, Ethanol, Ether, Acetone Potassium permanganate, 3-Amino-l,2,4-triazole, Sodium hydroxide. Sodium bisulfite. Hydrochloric acid. Nitric acid, Acetic anhydride. Acetone... 

NTND 2-Methyl-2-amino- 1,3-propanediol, Nitroform, Formaldehyde, Ethanol, Magnesium sulfate, Acetic anhydride, Nitric acid, Sodium bicarbonate... 

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