4,5-Dichloro-1,2,3-dithiazolium chloride (Appel's Salt): Reactions with N-nucleophiles.

Abstract

Different N-nucleophiles have been reacted with 4,5-dichloro-1,2,3-dithiazolium chloride (Appel's Salt), producing imines containing the 1,2,3-dithiazole ring.

Synthesis of [(4-Chloro-5H-1,2,3-dithiazol-5-ylidene)amino]azines

“…Also notable was that the reaction between 2-aminopyridine and Appel salt 4 was less sensitive to the base used, which tentatively may be attributed to two factors: (1) The pyrid-2-yl nitrogen’s ability to coordinate with the dithiazole sulfur S-1 in a “non-bonding” manner [ 29 , 30 ] provided particularly stable (dithiazolylidene)pyridinamines; and (2) the acidity of the proton in intermediate 6 was enhanced by both the neighbouring pyridyl nitrogen and the positively charged dithiazolium ring sulfur [ 9 , 23 ]. Both these features could lead to a very facile base catalysed elimination of HCl ( Scheme 3 ).…”

“…Despite their synthetic utility the library of dithiazolimines prepared from Appel salt 4 is comprised mainly of analogues where the dithiazolimine moiety is bound to a benzene ring. Some examples also exist where the dithiazole moiety is bound to 5-membered heteroles [ 21 , 22 , 23 ], but to the best of our knowledge the only reported examples, where the dithiazolimine moiety is bound directly to a 6-membered azine, are N -(4-chloro-5 H -1,2,3-dithiazol-5-ylidene)pyridin-2-amine ( 1a) [ 24 ], N 3 -(4-chloro-5 H -1,2,3-dithiazol-5-ylidene)- N 2 -phenylpyridine-2,3-diamine ( 2 ) [ 25 ] and N 2 , N 3 -bis(4-chloro-5 H -1,2,3-dithiazol-5-ylidene)pyridine-2,3-diamine ( 3 ) [ 25 ] ( Figure 1 ).…”

Expedient Synthesis of Electronically Modified Luciferins for Bioluminescence Imaging

“…21 Appel’s salt condenses readily with arylamines, and the resulting iminodithiazoles can be easily opened with a variety of nucleophiles. 22 If the nucleophile is present on the aniline itself (as in the case of ortho -amino anilines), cyanobenzimidazole structures can be isolated directly. In the absence of intramolecular nucleophiles, the dithiazole adduct can be fragmented with a variety of exogenously supplied reagents.…”

“…When amidine bases are used, dithiazole cleavage provides thioformamides; molecules of this sort can be readily cyclized to cyanobenzothiazoles. 22 …”

The Reaction of 4,5-Dichloro-1,2,3-dithiazolium Chloride with Sulfimides: A New Synthesis of N-Aryl-1,2,3-dithiazolimines

“…), the corresponding N -aryl-4-chloro-5 H -1,2,3-dithiazolimines 2 in good to excellent yields [ 20 , 21 ] ( Scheme 1 ). In some cases, such as with arylamides [ 22 ], heteroarylamines [ 21 , 23 ] or alkylamines [ 20 , 21 ], the reactions are low yielding or complex. As such this simple condensation reaction has room for improvement.…”