Butylammonium chloride

Benzyltriethylammonium chloride [56-37-1] is the most widely used catalyst under strongly basic conditions. Methyltrioctylammonium chloride [5137-55-3] (Ahquat 336, Adogen 464) is probably the least expensive catalyst. Others of high activity and moderate price are tetra- -butylammonium chloride [1112-67-0] bromide [1643-19-2] hydrogen sulfate [32503-27-8], tetra- -butylphosphonium chloride [2304-30-5], and other phosphonium salts of a similar number of C atoms. Many other onium salts can also be utilized. 

Tetra-n-butylammonium chloride [1112-67-0] M 277.9, m 15.7". Crystd from acetone by addition of diethyl ether. Very hygroscopic and forms crystals with 34H2O. 

Penton and Zollinger (1979, 1981 b) reported that this could indeed be the case. The coupling reactions of 3-methylaniline and A,7V-dimethylaniline with 4-methoxy-benzenediazonium tetrafluoroborate in dry acetonitrile showed a number of unusual characteristics, in particular an increase in the kinetic deuterium isotope effect with temperature. C-coupling occurs predominantly (>86% for 3-methylaniline), but on addition of tert-butylammonium chloride the rate became much faster, and triazenes were predominantly formed (with loss of a methyl group in the case of A V-di-methylaniline). Therefore, the initial attack of the diazonium ion is probably at the amine N-atom, and aminoazo formation occurs via rearrangement. 

FIG. 9 Upper potential values, a.sds lower potential values, b.sds of the first oscillation at the interface between phases o and wl of the octanol membrane (A), interfacial potential of a two-phase octanol-water system in the absence of SDS, c.sds (B) and those in the presence of 10 mM SDS (in the case of inorganic electrolyte, 1 mM), d.sds (C)- TMACI tetramethylammonium chloride TEACI tetraethylammonium chloride TPACI tetrapropylammonium chloride TBACI tetra-butylammonium chloride AcNa sodium acetate PrNa sodium propionate, BuNa sodium n-butyrate VaNa sodium w-valerate. (Ref 27.)... 

Figure 9 (C) and (B) show interfacial potential of the two-phase system in the presence of SDS and inorganic and organic electrolytes in the aqueous phase and tetra-butylammonium chloride in the octanol phase, iiD,sDS> and interfacial potential in the absence of SDS, iJc.sDS respectively. The potential of the octanol phase was measured in reference to the aqueous phase. The effects of electrolytes on c,sds and i D,sDS were the same for the most part as those on a,sds and iJs.sDS respectively, and differences between Eqsds and Tsdsds were essentially as much as those between a,sds and...

A final observation consistent with rate-determining cycli-zation is that the reaction rate is relatively insensitive to added electrolyte. Addition of 0.5 equivalents of tetra-n-butylammonium chloride or tetra-n-butylammonium azide to chloroform solutions of... 

Valproic acid can be potentiometrically titrated with standardized 0.1 N tetra-n-butylammonium hydroxide in chlorobenzene using a modified glass-calomel electrode system, in which 1.0 M aqueous tetra-n-butylammonium chloride has been substituted for potassium chloride, and employing acetone as the sample solvent. 

The following quaternary ammonium salts are used as phase transfer catalyst tetra-K-butylammonium chloride (TBAC), tetra-n-butylammonium bromide (TBAB), benzyltriethylammonium chloride (BTEAC), and benzyltriethylammo-nium bromide (BTEAB). Chlorinated hydrocarbons, such as dichloromethane (DCM), chloroform (CF), tetrachloromethane (TCM), 1,2-dichloromethane (DCE), and nitrobenzene (NB) are used as solvents. The effects of phase-transfer catalyst and solvent on the yield and reduced viscosity are summarized in Table 9.1. 

Oxiranes undergo ring opening with trialkylsilyl chlorides to yield trialkylsilyl chloroethyl ethers [51]. The reaction has been shown to be catalysed by tetra-n-butylammonium chloride, although most studies have used triphenylphosphine as the catalyst. Substituted oxiranes are cleaved by haloalkanes to yield the corresponding l-ch oro-2-aIkoxy-2-substituted alkanes [52] (see Section 9.3). 

The reaction of sodium azide with N-aryl chloroimines, obtained from benzanilides and thionyl chloride, to form 1,5-disubstituted tetrazoles is catalysed by tetra-n-butyl-ammonium bromide (Scheme 5.26, Table 5.40) [18] in variable yields, but generally <85%. 5-Butyl-2,3-diphenyltetrazolium salts have also been used as catalysts [18, 19]. 1,5-Disubstituted tetrazoles are also obtained from a one-pot sequential reaction of carbodimides with sodium azide and an aroyl chloride in the presence of tetra-n-butylammonium chloride [20]. 5-Chlorotetrazoles are obtained from the catalysed reaction of aryldichloroisocyanides with sodium azide (Scheme 5.26) [21],... 

It has been reported that the conversion of carbonyl compounds into their oximes, which is normally acid-catalysed, can be effected under basic conditions in the presence of tetra-n-butylammonium chloride [37]. Good yields are generally obtained with most aldehydes and ketones with the exception of benzophenone. 

Unsaturated nitriles have been obtained from the SN. reaction of 3-chloroalk-1 -enes [22] using tetra-n-butylammonium iodide as the catalyst. Under the basic reaction conditions, isomerism occurs such that not only is the 1-cyanoalk-2-ene obtained, but also the conjugated 1-cyanoalk-l-ene. Surprisingly, when tetra-n-butylammonium chloride is used, direct SN displacement of the chloro group occurs, followed by isomerization, to give the 3-cyanoalk-2-ene. 

P-Phenylation of a,p-unsaturated ketones in high yield (75-85%), using the palladium catalysed reaction with phenylmercury(II) chloride or tetraphenyltin(IV), is promoted by tetra-n-butylammonium chloride [37],... 

Optimum yields of (3-vinyl-y-butyrolactols from the Pd(II) promoted reaction of vinyl triflates with Z-but-2-en-l,4-diol (Scheme 6.33) are attained when tetra-n-butylammonium chloride is added (47]. The lactol is conveniently oxidized to the lactone with celite-supported silver carbonate. The corresponding arylbutyrolactols are obtained in high yield (70-80%) from an analogous reaction of iodoarenes with the enediol. The yields of 2-alkenyl-2,5-dihydrofurans, resulting from the Pd(0) catalysed reaction of cyclic alkynylcarbonates with acrylic esters via tandem C-C and C-0 bond forming reactions, are enhanced by the presence of tetra-n-butyl-ammonium fluoride (e.g. Scheme 6.33) (48]. 

Compared with primary and secondary amines, tertiary amines are virtually unreac-tive towards carbenes and it has been demonstrated that they behave as phase-transfer catalysts for the generation of dichlorocarbene from chloroform. For example, tri-n-butylamine and its hydrochloride salt have the same catalytic effect as tetra-n-butylammonium chloride in the generation of dichlorocarbene and its subsequent insertion into the C=C bond of cyclohexene [20]. However, tertiary amines are generally insufficiently basic to deprotonate chloroform and the presence of sodium hydroxide is normally required. The initial reaction of the tertiary amine with chloroform, therefore, appears to be the formation of the A -ylid. This species does not partition between the two phases and cannot be responsible for the insertion reaction of the carbene in the C=C bond. Instead, it has been proposed that it acts as a lipophilic base for the deprotonation of chloroform (Scheme 7.26) to form a dichloromethylammonium ion-pair, which transfers into the organic phase where it decomposes to produce the carbene [21]. 

Benzyltriethylammonium chloride is frequently used as the phase-transfer catalyst, but it has been noted that the catalyst itself produces phenylacetic acid under the carbonylation conditions [6]. Trimethyl(phenyl)ammonium chloride and tetra-n-butylammonium chloride both catalyse the reaction efficiently. 

Triazolines have been aromatized in good yield under two-phase conditions using potassium permanganate in the presence of tetra-n-butylammonium chloride [49]. 

It has been claimed that chromium trioxide reacts with tetra-n-butylammonium chloride in water to produce tetra-n-butylammonium chromate, n-Bu4N+HCr04- [7], whereas benzyltriethylammonium dichromate is obtained from the closely analogous reaction of benzyltriethylammonium chloride with chromium trioxide in dilute hydrochloric acid [8]. 

Methoxyphenol (6.21 g) and tetra-n-butylammonium chloride hydrate (100 mg) were dissolved in dichloromethane (40 mL) in a 100 mL three-necked flask. 

PDI = 1.5) when carried out at —15°C [Katayama et al., 2001]. The reaction converts to LCP with PDI <1.2 when the polymerization temperature is lowered to —78°C or tetra-n-butylammonium chloride is added. Mild nucleophiles such as esters, ethers, sulfides, and pyr-idines are also useful to decelerate the reaction rate, narrow PDI, and yield LCP [Aoshima and Higashimura, 1989 Cho et al., 1990 Kishimoto et al., 1989]. 

Although the Sonogashira reaction is normally performed with a copper cocatalyst, a copper-free, one-pot procedure for direct coupling with l-aryl-2-trimethylsilylacetylenes has been developed <2005T2697>. The procedure uses a mixture of palladium acetate and tri(o-tolyl)phosphine as catalyst in the presence of tetra- -butylammonium chloride... 

Vinyl iodides are considerably more reactive than bromides in the vinylations. It may be presumed that chlorides are not generally useful, with one exception noted below, since they have not been employed in the reaction. The bromides are usually reacted with a palladium acetate-triphenyl- or tri-o-tolyl-phos-phine catalyst at about 100 C. The reaction will occur without the phosphine if a secondary amine is present. Vinyl iodides will react in the absence of a phosphine even with only a tertiary amine present.48 37 The iodides are so reactive, in fact, that reactions occur even at room temperature if potassium carbonate is the base and tetra-zi-butylammonium chloride is used as phase transfer agent in DMF solution when palladium acetate is the catalyst.88... 

The same reactions, carried out with potassium carbonate as base in place of a secondary amine, yield exocyclic dienes in good yield, although double-bond isomerization sometimes occurs (equation 38).93 Inclusion of tetra-zi-butylammonium chloride in the reaction mixture stops the double-bond isomerization. Thus, the reaction in equation (38) with the chloride yields only the bis(exomethylene) product in 45% yield in a slow reaction. Some N- and O-heterocyclic products, also, have been prepared by the intramolecular vinyl substitution reaction.94 A 16-membered ring lactone was made by the ring closure of a vinylic iodide group with a vinyl ketone group. The yield, based upon the reactant, was 55% but a stoichiometric amount of bis(acetonitrile)palladium dichloride was employed. The catalyst was prereduced with formic acid so that the reaction proceeded at 25 C (equation 39).95... 

In a similar fashion, the absorption of DSCG was improved by the addition of tetraalkylammonium salts. The fat solubility of the salt correlated with its ability to improve penetration. That is, the rank order of lipophilicity and the ability to improve the permeation of DSCG is choline chloride, tetraethylammonium chloride, tetra-n-butylammonium chloride. 

Jinnai et aL [18] measured by neutron-scattering the interlayer separation between the butylammonium vermic-ulite platelets as a function of the poly(vinyl methyl ether) (PVME) volume fraction in an aqueous butylammonium chloride solution. The n-butylammonium vermiculite swelled in the n-butylammonium chloride solution, and the interlayer separation of the platelets increased from 2 to 12 nm at 8<7 <20 °C. When the PVME was added to this... 

An automatic titrator is used in conjunction with a glass indicating electrode and a calomel reference electrode. The saturated KC1 electrolyte in the calomel electrode must be replaced by 1M tetra-n-butylammonium chloride (TnBACl) in water which is available as polarographic grade material (Southwestern Analytical Chemicals, Austin, TX). The electrode is stored in the TnBACl solution when not in use. A nitrogen flow of 50 ml min-1 is maintained over the solution in the titration vessel. 

FIGURE 1.4 Schematic illustration of the swelling of n-butylammonium vermiculite. (a) shows the unexpanded in a 1.0 M butylammonium chloride solution, (b), (c) and (d) show the gels formed in 0.1 M, 0.01 M and 0.001 M solutions, respectively. Note how the extent of swelling is suppressed by an increase in the salt concentration. V represents the volume occupied by the clay, with V the volume of the whole condensed matter system (clay plus excess soaking solution.)... 

The samples for the diffraction experiments were prepared as follows. A crystal of the n-butylammonium vermiculite was cut to a thickness of about 0.5 mm and an area of about 5x5 mm and soaked in the appropriate solution of protonated n-butylammonium chloride in D20. DzO was used because it gave a lower incoherent-scattering background than H20. The gel was allowed to come to its equilibrium swelling distance for 48 hours in a cold room at a temperature of 7°C. A slice of this swollen gel about 1 mm thick was then transferred to a quartz cell of internal dimensions 30 x 5 x 2 mm. The remainder of the quartz cell was filled with some of the original solution. The cell was sealed with Parafilm to prevent loss of solution by evaporation, clamped into an aluminum block, as shown in Figure 1.5, and... 

FIGURE 1.10 Relationship between interlayer distance of butylammonium vermiculite and concentration of butylammonium chloride in external solution (c expressed in units of M). (Reproduced with kind permission of the Clay Minerals Society, from Garrett, W.G. and Walker, G.F., Clays Clay Min., 9, 557, 1962.)... 

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