Aluminium Chloride and Sodium Iodide (AlCl₃-NaI): A Versatile Dehydrating Agent

Abstract

Compounds and nitrile group functionality play an important role in organic syntheses. 1 Many synthetic 2 and biologically active compounds 3 are derived from nitrile group participation.A number of methods have been developed for the conversion of aldoximes and amides into nitriles using dehydrating agents such as: 4,6-diphenyl-2-methylthiopyrylium tetrafluoroborate, 4 Vilsmeier reagents, 5 sulphuryl chloride fluoride, 6 phosphorus tri-iodide, 7 chlorosulfonyl isocyanate, 8 trifluoroacetic anhydride, 9 iodotriethoxyphosphoranes, 10 benzenesulfenyl chloride, 11 diphosphorus tetraiodide, 12 phosphoryl halide and imidazolide, 13 selenium dioxide, 14 phosphorus trichloride, 15 chlorodimethylsulfonium chloride, 16 triflic anhydride, 17 dicyclohexylcarbodi-mide, 18 phenyl chlorosulfite, 19 phosphonitrile chloride, 20 carbenes, 21 1,1-dicarbonyldi-imidaxzole, 22 cyanuric chloride. 23

Anchimerically Assisted Cleavage of Aryl Methyl Ethers by Aluminum Chloride‐Sodium Iodide in Acetonitrile

“…The ether cleaving species in AlCl 3 ‐NaI mediated demethylation reactions was unclear. It was proposed by Konwar and co‐workers that reaction of AlCl 3 and NaI provided aluminum triiodide in situ as the reactive species in acetonitrile during the dehydrating of oximes and amides . We have noted that AlI 3 ‐DIC reagent system is efficient in cleaving isoeugenol ( 4 k ) and other phenyl alkyl ethers such as 3‐methoxyphenol ( 4 n ) and 2‐isopropoxyphenol ( 4 q ) .…”

Recent developments in dehydration of primary amides to nitriles

“…34 Konwar and coworkers developed a method for the dehydration of oximes and amides in hydrated media to their corresponding nitriles in good yields using an AlCl 3 •6H 2 O/KI/ H 2 O/CH 3 CN system (Scheme 4). 35 The same group has also reported anhydrous AlCl 3 -KI mediated dehydration of amides. In the presence of water, aluminium is coordinated with amide-nitrogen and in anhydrous medium it is coordinated with amide-oxygen and facilitates the removal of water from the amide to form the corresponding nitrile (Scheme 4).…”