Search

We report an efficient procedure for the synthesis of symmetrical disulfanes from organic thiocyanates in the presence of sodium in silica gel at room temperature. By avoiding the use of foul-smelling thiols, the present protocol provides an attractive alternative to existing methods for the preparation of symmetrical disulfanes.

Retrospective detection and identification of markers of chemical warfare agents are important aspects of verification of the Chemical Weapons Convention. Alkyl alkylphosphonic acids (AAPAs) and alkylphosphonic acids (APAs) are important markers of nerve agents. We describe the development and optimization of a new gas chromatography/mass spectrometry (GC/MS) injection port fluorination method for the derivatization of AAPAs and APAs. The process involved the injection of acids with trifluoroacetic anhydride in GC/MS, where acids are converted into their corresponding volatile fluorides. Various reaction conditions such as fluorinating agent, injection port temperature and splitless time were optimized. The maximum reaction efficiency of the acids with trifluoroacetic anhydride was observed at 230°C injection port temperature with a splitless time of 2 min. APAs showed best analytical efficiencies at 400°C injection port temperature, while the other conditions were similar to those of AAPAs. The linearities of response for APAs and AAPAs were in the range of 1–25 and 5–100 µg mL−1, respectively, with limits of detection ranging from 500 pg to 800 ng mL−1. Copyright © 2007 John Wiley & Sons, Ltd.

substituted thioamides starting from acyl halides and amines is an attractive method as it allows an easy introduction of diverse building blocks for constructing desired thioamides. This is a two step procedure. For avoiding a lengthy separation process and purification of intermediate, one-pot preparation techniques are highly preferred. The potential of one-pot procedure is enhanced if applied with microwave heating under solvent-free condition

Direct conversion of phosphorus(V) chlorides to the corresponding phosphorus(V) fluorides was achieved using a solid reagent, tetrabutylammonium tetra (tert-butyl alcohol) coordinated fluoride. The phosphorus(V) fluorides were directly synthesized and efficiently isolated in very good yields.

A convenient, highly efficient, safe microwave-mediated Salkylation of O,O’-dialkyl thiophosphate has been reported. Clean and rapid S-alkylation of thiophosphates can be achieved by irradiating a mixture of dialkylthiophosphate salt and alkyl halide under microwave for a brief period. Alkylation occurs exclusively at sulfur to provide S-alkylated products. Through a simple workup, pure compounds have been obtained easily in good yields.

An efficient and operationally simple method is developed for the synthesis of dialkyl chlorophosphates from dialkylphosphites using a new chlorine bearing reagent, N,N-dichloro poly(styrene-co-divinyl benzene) sulfonamide in the form of polymeric beads. The reagent afforded dialkyl chlorophosphates at room temperature, and is recyclable.

This article describes a one pot, solvent free, microwave assisted synthesis of O,O-dialkyl dialkylpyrophosphonates (DADAPP) from O-alkyl alkylphosphonic chlorides 2a–j with 4-dimethylaminopyridine (DMAP) in the presence of water under microwave irradiation. The reaction takes place by the phosphonium salts, which are converted into the DADAPPs 4a–j. These DADAPPs are important markers of chemical warfare agents sarin, soman, and VX and their analogues. The method has several advantages over the conventional methods such as operational simplicity, high yield, and reduced reaction time.