Methyl acetate ammonium iodide

N-Methylethylamine has been prepared by heating ethyl-amine with methyl iodide in alcohol at 100° 3 by the hydrolysis of N-methyl-N-ethylarenesulfonamides,4-5 -nitroso-N-methyl-N-ethylaniline,6 or methylethylbenzhydrylidene ammonium iodide 7 by catalytic hydrogenation of ethyl isocyanate or ethyl isocyanide 8 and by the reduction of ethyl isocyanate by lithium aluminum hydride,9 of N-methylacetisoaldoxime by sodium amalgam and acetic acid,10 or of a nitromethane/ethylmagnesium bromide adduct by zinc and hydrochloric acid.11... 

Other companies (e.g. Hoechst, now Celanese) have developed a slightly different process in which the water content is low in order to save CO feedstock [1], In the absence of water it turned out that the catalyst precipitates. Also, the regeneration of ihodium(III) is much slower. The formation of the trivalent rhodium species is also slower because the HI content is much lower when the water concentration is low. The water content is kept low by adding part of the methanol in the form of methyl acetate. Indeed, the shift reaction is now suppressed. Stabilisation of the rhodium species and lowering of the HI content can be achieved by the addition of iodide salts (Li, ammonium, phosphonium, etc). Later, we will see that this is also important in the acetic anhydride process. High reaction rates and low catalyst usage can be achieved at low reactor water concentration by the introduction of tertiary phosphine oxide additives [1]. 

The basic organometallic reaction cycle for the Rh/I catalyzed carbonylation of methyl acetate is the same as for methanol carbonylation. However some differences arise due to the absence of water in the anhydrous process. As described in Section 4.2.4, the Monsanto acetic acid process employs quite high water concentrations to maintain catalyst stability and activity, since at low water levels the catalyst tends to convert into an inactive Rh(III) form. An alternative strategy, employed in anhydrous methyl acetate carbonylation, is to use iodide salts as promoters/stabilizers. The Eastman process uses a substantial concentration of lithium iodide, whereas a quaternary ammonium iodide is used by BP in their combined acetic acid/anhydride process. The iodide salt is thought to aid catalysis by acting as an alternative source of iodide (in addition to HI) for activation of the methyl acetate substrate (Equation 17) ... 

The tertiary amine group in this last compound being more strongly basic than the primary amine group in amino acetic acid would more readily form an inner ammonium salt. There is also a tetra-methyl ammonium iodide compound formed analogous to the tetra-methyl ammonium salts of the alkyl amines. 

Tetra-methyl ammonium acetic acid iodide normal acid)... 

Orthoesters are converted into esters with TMS-I. The dimethyl acetal of formaldehyde, methylal, affords iodomethyl methyl ether in good yield (eq 12) 7a (in presence of alcohols, MOM ethers are formed). 7b a-Acyloxy ethers also furnish the iodo ethers, e.g. the protected 8-acetyl ribofuranoside gave the a-iodide which was used in the synthesis of various nucleosides in good yield (eq 13). Aminals are similarly converted into immonium salts, e.g. Eschenmoser s reagent, Dimethyl(methylene)ammonium Iodide, in good yield. ... 

Acetamide Alkyl trimethyl ammonium chloride Ammonium caprylate Benomyl Benzimidazole carbamate 1,2-Benzisothiazolin-3-one Benzyltriethyl ammonium chloride Chlorine dioxide p-Chloro-m-cresol Chlorophene Cocodiamine acetate Dialkyl methyl benzyl ammonium chloride DIchlorobenzyl alcohol DImethoxytetrahydrofuran DM DM hydantoin Glyoxal Hexachlorophene Hydrogenated tallowtrlmonlum methosulfate N,N -Methylene bismorphollne 2-Methyl-4,5-trlmethylene-4-lsothlazolln-3-one Quaternlum-18 methosulfate Thiophanate Tributyl phosphine Tributyl (tetradecyl) phosphonlum chloride Trioctyl (octadecyl) phosphonlum Iodide VInylene bisthlocyanate biocide mfg. 

Benzyl trimethyl ammonium hydroxide Cetrimonium bromide Dimethyl diallyl ammonium chloride Laurtrimonium bromide Laurtrimonium chloride Methyl tributyl ammonium chloride Tetrabutyl ammonium bromide Tetrabutyl ammonium chloride Tetrabutyl ammonium fluoride Tetra-n-butyl ammonium hydrogen sulfate Tetra-n-butyl ammonium hydroxide Tetrabutyl ammonium iodide Tetrabutylphosphonium acetate, monoacetic acid Tetrabutylphosphonium bromide Tetrabutylphosphonium chloride Tetraethylammonium bromide Tetraethylammonium hydroxide Tetrakis (hydroxymethyl) phosphonium chloride Tetramethylammonium bromide Tetramethylammonium chloride Tetramethylammonium hydroxide Tetramethyl ammonium iodide Tetraphenyl phosphonium bromide Tetrapropyl ammonium bromide Tetrapropyl ammonium iodide Tributylamine Tributyl phosphine Tributyl (tetradecyl) phosphonium chloride Trioctyl (octadecyl) phosphonium iodide catalyst, phase-transfer Tetraethylammonium chloride Tetraoctylphosphonium bromide Tri-n-butyl methyl ammonium chloride Tri methyl phenyl ammonium hydroxide catalyst, phenolics Triethylamine... 

The amount of reddish-purple acid-chloranilate ion liberated is proportional to the chloride ion concentration. Methyl cellosolve (2-methoxyethanol) is added to lower the solubility of mercury(II) chloranilate and to suppress the dissociation of the mercury(II) chloride nitric acid is added (concentration 0.05M) to give the maximum absorption. Measurements are made at 530nm in the visible or 305 nm in the ultraviolet region. Bromide, iodide, iodate, thiocyanate, fluoride, and phosphate interfere, but sulphate, acetate, oxalate, and citrate have little effect at the 25 mg L 1 level. The limit of detection is 0.2 mg L 1 of chloride ion the upper limit is about 120 mg L . Most cations, but not ammonium ion, interfere and must be removed. 

Cyclopentanone Cyanoacetic acid Ammonium acetate Hydrogen Magnesium Methyl iodide Methylamine Hydrogen chloride... 

The P-methylphosphonium derivative has been made by cyclization of tris(hydroxymethyl)methylphosphonium iodide with ammonium acetate (77CZ304). An incorrect abstract (87CA184600) of this work suggests that direct P-methylation is possible. X-Ray, NMR, and IR spectra are reported. [78ZN(B)1257] The X-ray spectra show C—P—C angles of about 102° and Me—P—C angles of 116°. 

The dimethyl amine derivative produced was quaternized directly by methyl iodide, added slowly to a chilled solution of the ternary amine in ethyl acetate. When other ring substituents are present, the reductive eunination leads to isomeric configurations, as noted in Table I. Quaternary ammonium halide salts were characterized by melting point, TLC, or microanalytical data and and NMR. 

When it is not possible to employ potassium chloride solution, e.g., if one of the junction solutions contains a soluble silver, mercurous or thallous salt, satisfactory results can be obtained with a salt bridge containing a saturated solution of ammonium nitrate the use of solutions of sodium nitrate and of lithium acetate has also been suggested. For non-aqueous solutions, sodium iodide in methyl alcohol and potassium thiocyanate in ethyl alcohol have been employed. 

Scheme 6.42, diisopropylidene mannitol was treated with A, A -dimethylformamide dimethyl acetal followed by methyl iodide to effect this transformation [74,75]. The reaction proceeds through initial acetal transfer generating the illustrated mannitol acetal. Methyl iodide then alkylates the nitrogen, producing a quaternary ammonium salt. Loss of trimethylamine, followed by ring opening and decomposition, gives the 3,4-olefinic mannitol derivative shown. 

---