Ammonium trifluoroacetates

Methylammonium N Ethyl N methylcyclopentyl chlonde ammonium trifluoroacetate... 

Other methods of nitration that Laali investigated were with isoamyl nitrate in combination with a Bronsted or Lewis acid in several ionic liquids, with [EMIM][OTf] giving the best yields (69 %, 1.0 1.0 o p ratio). In the ionic liquid [HNEt( Pr)2] [CE3CO2] (m.p. = 92-93 °C), toluene was nitrated with a mixture of [NH4][N03] and trifluoroacetic acid (TEAH) (Scheme 5.1-37). This gave ammonium trifluoroacetate [NH4][TEA] as a by-product, which could be removed from the reaction vessel by distillation (sublimation). 

REGIOSELECTIVE MANNICH CONDENSATION WITH DIMETHYL(METHYLENE)AMMONIUM TRIFLUOROACETATE 1-DIMETHYLAMINO-4-METHYL-3-PENTANONE... 

The less highly substituted Mannich bases can also be prepared directly from ketones and dimethyl(methylene)ammonium trifluoroacetate by the procedure reported here, which takes advantage of the isomerization of Mannich bases in trifluoroacetic acid. (In acetic acid the Mannich bases undergo elimination of dimethylamine to give a-methylene ketones.) This method is rapid and affords products having an isomeric purity of at least 90% without difficult separations. The 49-57% yield of l-(di-methylamino)-4-methyl-3-pentanone obtained with this procedure compares favorably with the overall yields of amino ketones prepared by the indirect routes mentioned previously. 

Butanone, 4-(dimethylamino)-3,3-dimethyl- (8, 9) (53921-82-7) Dimethyl(methylene)ammonium trifluoroacetate Ammonium, di-methylmethylene-, salt with trifluoroacetic acid (1 1) (8) ... 

Trimethylsilylation is adversely affected by moisture, and therefore, hydrolyzates should be evaporated to dryness as completely as possible. If trimethylsilylation is catalyzed by trifluoroacetic acid, instead of chlorotrimethylsilane, moderate proportions of water may be tolerated,117,127-129 but, even under these conditions, extra peaks may be obtained from partly trimethylsilylated derivatives.130 Catalysis with trifluoroacetic acid is useful when aqueous aliquots from a reaction are to be trimethylsilylated.131 A further advantage of this method, which has been used in the determination of 1,6-anhydro-jS-D-glucopyranose in corn syrup,132 for cycloamyloses,133 and for a series of malto-oligosaccharides,134 is that ammonium trifluoroacetate is soluble in pyridine. 

Oxidation of 51 by method A and subsequent treatment of 55 with ammonium trifluoroacetate 57 in the presence of diisopropylethylamine provided 58 in 67% yield. 

Table 6.16 Chiral ammonium trifluoroacetate-catalyzed Strecker reactions.

Fig. 8.6. Proton-induced decomposition of /(/-substituted carbamic acid B into carbon dioxide and a primary ammonium trifluoroacetate—a reaction occuring during the acidic deprotection of a Boc-pro-tected amine.

Thus when molten ammonium trifluoroacetate (mp 130°C) is treated with LiH, deuteration studies show isotopic scrambling. Although it could be that D impinges only on the hydrogen of NHJ, another possibility is... 

ALDOL CONDENSATION (+)-(R)-l-Amino-2- methoxymethyl)pyrrolidine. Boron trichloride. Dialkylboron tri-fluoromethanesulfonates. Dibenzyl-ammonium trifluoroacetate. Di- -butylboryl trifluoromethanesulfonate. Dichlorodiethylaminoborane. Diiso-propylaluminum phenoxide. Diisopropyl-aminomagnesium bromide. Lithium diisopropylamide. Morpholine-Camphoric acid. Proline. 

Heating / -keto-esters 187 with molten ammonium trifluoroacetate at 150 °C readily gives oxazoles 188 (Scheme 52). The amino stereogenic center was not epimerized under these conditions. This method allows access to oxazole-5-esters, which are not easily obtained using methods presented in the previous section. The / -keto-esters 187 were synthesized via nucleophilic displacements on chlorides 186 using A -protected a-amino acids 185 <2005SL2072>. 

Initially, MPH was extracted from plasma by LLE with cyclohexane. The reconstituted analytes were analysed using LC-MS [57]. A [ CDg]-analogue was used as ILIS. LC was performed using a 150x4.6-nun-ID Chirobiotic V column (5 pm) and methanol with 0.05% ammonium trifluoroacetate as mobile phase at a flow-rate of 1.0 ml/min. The first 3 min of the run were diverted to waste. The total ran time was only 7.5 min. The plasma-concentration-time profile for a child with ADHD after an oral administration of 17.5 mg of racemic MPH showed considerably higher plasma levels of d-threo-MPYi, as expected. The LOQ of this method was 87 pg/ml. This method was also applied in toxicokinetic studies in rat, rabbit, and dog [59]. In a further study [58], a semi-automated LLE in 96-well plate format was developed and validated. No chiral column was used in this case. 

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