Quaternary ammonium salts iodides

At about the same time, BP Chemicals, ivho ivere also licensors of the Monsanto process, developed their oivn process for carbonylation of a mixed MeOH/MeOAc/ H2O feed to AcOH and AC2O using a Rh and Mel catalysed process promoted with a quaternary ammonium iodide salt ([QAS]I), [7]. 

The spectral data for kinabalurine D (47) showed it to be yet another 7-hydroxy-skytanthine diastereomer but proved inadequate for definitive assignment of stereochemistry. To this end kinabalurine D was converted to the quaternary ammonium iodide salt which provided suitable crystals for X-ray analysis. Kinabalurine D differs from kinabalurines A-C in having a 4-P-methyl group and a trans ring junction in which the stereochemistry of H(5)... 

A process for the coproduction of acetic anhydride and acetic acid, which has been operated by BP Chemicals since 1988, uses a quaternary ammonium iodide salt in a role similar to that of Lil [8]. Beneficial effects on rhodium-complex-catalyzed methanol carbonylation have also been found for other additives. For example, phosphine oxides such as Ph3PO enable high catalyst rates at low water concentrations without compromising catalyst stability [40—42]. Similarly, iodocarbonyl complexes of ruthenium and osmium (as used to promote iridium systems, Section 3) are found to enhance the activity of a rhodium catalyst at low water concentrations [43,44]. Other compounds reported to have beneficial effects include phosphate salts [45], transition metal halide salts [46], and oxoacids and heteropolyacids and their salts [47]. 

The efficacy of an iridium/iodide catalyst for methanol carbonylation was discovered by Monsanto at the same time as their development of the process using the rhodium/iodide catalyst [5]. Mechanistic investigations by Forster employing in situ HPIR spectroscopy revealed additional complexity compared to the rhodium system [115]. In particular, the carbonylation rate and catalyst speciation were found to show a more complicated dependence on process variables, and three distinct regimes of catalyst behavior were identified. At relatively low concentrations of Mel, H20, and ionic iodide, a neutral iridium (I) complex [Ir(CO)sI] was found to dominate, and the catalytic reaction was inhibited by increasing the CO partial pressure. Addition of small amounts of a quaternary ammonium iodide salt caused the dominant iridium species to become an Ir(III) methyl complex, [Ir(CO)2l3Me]. Under these conditions, the rate... 

The same effect has been demonstrated with salts such as quaternary ammonium iodides in HP IR experiments carried out at BP [51] even though no substantial amounts of acetate salts are observed. Millenium have reported that phosphine oxides similarly lead to increased [Rh(CO)2l2r 1 low H2O using HP IR to quantify Rh speciation [20]. 

Nikolic et al. reported the preparation and coulometric determination of quaternary ammonium iodides of procaine and of other local anesthetics [63]. After extraction from 0.33 M NaOH, the quaternary iodide salts were prepared by precipitation with methyl iodide in ethyl ether. The quaternary iodides were then coulometrically determined with the use of a Radiometer titrator. The method used a silver cathode and anode (in electrolytes of 2 M and 0.4 M H2SO4, respectively), and a reference mercurous sulfate electrode. For drug determinations in the range of 0.12 to 0. 96 mg, the standard deviations were typically found to be 4 to 8 pg. 

Quaternary ammonium iodides are attractive choices because they generally have good activity, low cost, and solubility in the reaction and recovery processes. Simple quaternization of the wide variety of available tri(n-alkyl) amines with n-alkyl iodides allows optimization of the tetra(n-alkyl) ammonium iodide salt properties ... 

Demetkylation of quaternary ammonium salts.3 Quaternary ammonium iodides arc dcmcthylated by treatment with this borohydridc at 25-65° in about 70-90% yield. Demethylulion is markedly favored over deethylation. 

Elimination of the quaternary ammonium salt generally takes place by the E2 mechanism, which requires a strong base. To provide the base, the quaternary ammonium iodide is converted to the hydroxide salt by treatment with silver oxide. 

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 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. 

Aminomethylation of lactone enolates with the Eschenmoser salt followed by neutralization (workup) yields the corresponding Mannich bases. Their conversion to quaternary ammonium iodides followed by treatment with DBU (1,5-diazabicy-clo[5.4.0]undec-5-ene) leads to a-methylene lactones. 

At early stages of the process development, it was discovered that all effective catalytic systems for DPC synthesis contained a bromide quaternary ammonium salt. Other bromide salts were practically inactive, while quaternary ammonium iodides and chlorides showed poor performance [51]. The DPC yield grows with bromide concentration, for example, in the catalytic package Pd(OAc)2/Co(acac)g/NBu Br up to the ratio Br Pd = 20 [21]. 

Pure PEO has also been used in an electrolyte for DSSC, by combining this polymer with different amounts of KI and Using Raman spectroscopy the authors showed the formation of polyiodide species in the electrolyte upon addition of different salt and iodine concentrations. The highest ionic conductivity achieved at room temperature was 8.4 x 10" S cm for the electrolyte composition PEOrKI 12 1 0.1. Fourier transform infrared (FTIR) spectroscopy was carried out to show that the K+ ions can coordinate to the ether oxygen in PEO chains and a linear Arrhenius-type behavior was observed. DSSC assembled with this electrolyte presented = 6.1 mA cm , Voc = 0.59 V, fill factor FF = 0.56 and rj = 2.0% under irradiation of 100 mW cm Polymer electrolytes containing different salts, such as quaternary ammonium iodides, or different polymers, such as poly(butylacrylate) and poly(dimethylsiloxane), have also been used in DSSC. 

Benzyltnmethyl ammonium iodide (a quaternary ammonium salt)... 

Because of its high reactivity toward nucleophilic substitution methyl iodide is the alkyl halide most often used to prepare quaternary ammonium salts... 

Physostigmme an alkaloid obtained from a West African plant is used in the treatment of glaucoma Treatment of physostigmme with methyl iodide gives a quaternary ammonium salt What IS the structure of this salt" ... 

Analytical methods iaclude thin-layer chromatography (69), gas chromatography (70), and specific methods for determining amine oxides ia detergeats (71) and foods (72). Nuclear magnetic resonance (73—75) and mass spectrometry (76) have also been used. A frequentiy used procedure for iadustrial amine oxides (77) iavolves titratioa with hydrochloric acid before and after conversion of the amine to the quaternary ammonium salt by reaction with methyl iodide. A simple, rapid quaHty control procedure has been developed for the deterrniaation of amine oxide and unreacted tertiary amine (78). 

Quaternary ammonium alkyl ethers are prepared similarly an alkaline starch is reacted with a quaternary ammonium salt containing a 3-chloto-2-hydtoxyptopyl or 2,3-epoxyptopyl radical. Alternatively, such derivatives can be prepared by simple quaternization of tertiary aminoalkyl ethers by reaction with methyl iodide. Sulfonium (107) and phosphonium (108) starch salts have also been prepared and investigated. Further work has explained the synthesis of diethyl aminoethyl starch (109) as well as the production of cationic starches from the reaction of alkaline starch with... 

In the case of nicotinamide, the color yield is often low. This problem can be circumvented by either hydrolysis to nicotinic acid or by conversion of the amide to a fluorescent compound. Treatment of nicotinamide with methyl iodide yields the quaternary ammonium salt, /V-methyl nicotinamide (5). Reaction of this compound with acetophenone yields a fluorescent adduct (49). Other carbonyl compounds have also been used (50—54). 

The dialkylamino, especially the dimethylamino, group in a cyclopentenone of type 67 can be alkylated with methyl iodide to yield a quaternary ammonium salt. Upon treatment with a base, these quaternary ammonium salts undergo... 

Certain quaternary ammonium salts will alkylate [Co (DMG)2py] . The addition of PhCH2NMc3 I to a solution of the complex in methanol gives the PhCH2Co complex in 45% yield. The reaction works more slowly with dimethylpiperidinium iodide to give the CH3—Co complex 15). There is no alkylation with tertiary amines alone 164), but in the presence of equimolar amounts of dimethylacetylenedicarboxylate certain aliphatic tertiary amines can alkylate [Co (DMG)2py] in methanol solution. The reaction also produces the enamine derivative of a maleic ester, and the mechanism appears to involve addition of the amine to the triple bond to form an ammonium salt, which can then attack the Co(I) derivative (75). 

It has been shown that the corrosion rates of various steels can be reduced to less than 1 mg/cm /hr using ternary inhibitor mixtures containing quaternary ammonium salts, trans-cinnamaldehyde, and potassium iodide in amounts of 0.2% of each component [1758]. 

A thio-substituted, quaternary ammonium salt can be synthesized by the Michael addition of an alkyl thiol to acrylamide in the presence of benzyl trimethyl ammonium hydroxide as a catalyst [793-795]. The reaction leads to the crystallization of the adducts in essentially quantitative yield. Reduction of the amides by lithium aluminum hydride in tetrahydrofuran solution produces the desired amines, which are converted to desired halide by reaction of the methyl iodide with the amines. The inhibitor is useful in controlling corrosion such as that caused by CO2 and H2S. 

The reaction of 5-[2-(iV,./V-dimethylamino)ethyl]-l,2,4-oxadiazole with methyl iodide forms the quaternary ammonium salt 170 (Scheme 22), which undergoes elimination in the presence of base (diisopropylethylamine (DIEA), TEA, l,8-diazabicyclo[4.3.0]undec-7-ene, etc.) to form an intermediate 5-vinyl-l,2,4-oxadiazole 171, which undergoes in situ Michael addition with nucleophiles to furnish the Michael adducts 172. As an example, also shown in Scheme 22, 3-hydroxy-pyrrolidine allows the synthesis of compound 172a in 97% yield. Mesylation followed by deprotonation of the 1,2,4-oxadiazole methylene at C-5 enables Sn2 displacement of the mesylate to give the 5-azabicycloheptyl derivative 173, which is a potent muscarinic agonist <1996JOC3228>. 

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