A one-pot procedure for trifluoroacetylation of arylamines using trifluoroacetic acid as a trifluoroacetylating reagent

A convenient procedure for the preparation of aryl trifluoroacetamides from aryl amines is described that employs 2-4 M equiv of trifluoroacetic acid in refluxing xylene as a trifluoroacetylating agent. Addition of an amount of pyridine that is equimolar to the amount of trifluoroacetic acid present in the reaction mixture facilitates the trifluoroacetylation of rather basic arylamines.     

Analysis of deethyl- and deisopropylatrazine residues in drinking and ground water by chemical derivatization

A gas chromatographic method with alkali flame ionization detection is described for the determination of residue levels (0.1 μg/I and below) of deethylatrazine and deisopropylatrazine in drinking and ground water. Confirmation of the identities of the compounds is achieved by trifluoroacetylation, reaction conditions for which are presented.     

Trifluoroacetylation of arylamines using poly-phosphoric acid trimethylsilylester (PPSE)

A new, simple and useful procedure is described for the trifluoroacetylation of arylamines using trifluoroacetic acid and poly-phosphoric acid trimethylsilylester (PPSE) as the condensation agent.     

Mg-promoted C-trifluoroacetylation of benzophenone

Mg-promoted reduction of benzophenones in the presence of ethyl trifluoroacetate and trimethylchlorosilane in N-methyl-2-pyrrolidinone afforded the corresponding cross-coupling products, which were easily transformed into C-trifluoroacetylated compounds of benzophenones through desilylation by tetrabutylammonium fluoride.     

Analysis of amines in petroleum

An analytical method for differentiation of primary, secondary, and tertiary amines using exhaustive trifluoroacetylation prior to GC/MS has been developed. Using the conditions described in the report, most primary amines add two and secondary amines add one trifluoroacetyl group. In general, tertiary amines do not react. GC retention indices and relative GC/MS total ion current response factors for 102 trifluoroacetyl derivatives are reported. Examples of the application of the method to petroleum and coal liquid products are provided. Because of the limited thermal stability of the derivatives of primary amines, the method is applicable only to distillates boiling below 370 °C (700 °F).     

Direct microwave promoted trifluoroacetylation of aromatic amines with trifluoroacetic acid

A simple microwave-promoted procedure has been developed for the direct preparation of trifluoroacetanilides. An equimolar mixture of substituted anilines and trifluoroacetic acid was microwave irradiated at short reaction times, giving the corresponding anilides in high yields and purity.     

微量糖缀合物中单糖组成的毛细管气相色谱分离和电子捕获检测

本文介绍了微量糖缀合物中单糖组成的电子捕获毛细管气相色谱分析,讨论了样品组分的分析条件。方法用于测定人脑神经节苷脂、人γ-球蛋白、微生物糖蛋白和植物多糖样品中的糖组分,样品量仅需0.1～5μg。     

A facile strategy to prevent trifluoroacetylation of N-terminal proline peptides

Unwanted trifluoroacetylation occurred at the N-terminus of prolinyl peptides during detachment from the solid phase. This was observed when the N-α-Fmoc protecting group had been removed prior to the final TFA treatment. Subtly changing the SPPS protocol and incorporating Boc- in place of the Fmoc-protected proline as the N-terminal building block efficiently suppressed this side reaction.     

High resolution-GLC of carbohydrates as their dithioacetal-trimethylsilylates and -trifluoroacetates

In the recent past, GLC separation of carbohydrates has significantly decreased in importance as a routine method compared with high resolution HPLC analysis. The reason for this is the handicap of most of the conventional derivatization procedures for GLC, i.e., formation of multiple derivatives with reducing sugars. Mercaptalation, the only method yielding a single derivative with each component, was rather complicated and therefore unpopular for routine work. In this paper a simplified mercaptalation is described which can be followed either by a trimethylsilylation or a trifluoroacetvlation and yields stable assays for chromatography. The combination with an optimized separation on megabore capillary columns results in a universally suited method, useful even with complex sample compositions. The separation power and speed of this method is at least comparable with high resolution HPLC analyses.