Reaction of trithiazyl trichloride with alkenes and alkynes

Synthesis of aromatic heterocycles

“…Alkenes and alkynes react readily with it to give mono-or disubstituted 1,2,5-thiadiazoles in one step; for example, DMAD gave the 3,4-dicarboxylic acid dimethyl ester 117 (84%). 179 Activated methylene compounds similarly give disubstituted 1,2,5-thiadiazoles; thus, the thiadiazole 118 was isolated (41%) from a reaction with dibenzoylmethane. 180 More exotic structures are obtained from reactions of trithiazyl View Online chloride with pyrroles; an example is the bis(thiadiazole) 119 formed (45%) with 1-methyl-2,5-diphenylpyrrole.…”

Recent Developments in the Synthesis and Applications of 1,2,5-Thia- and Selenadiazoles. A Review

“…With trisubstituted ethene (Z)-ethyl 4-phenyl-3-benzylbut-2-enoate debenzylation takes place giving 4-phenyl-1,2,5-thiadiazole-3-carboxylate. 83 Also this method provided a new and efficient two-step route to 3-amino-1,2,5-thiadiazole starting from Nvinylphthalimide, 85 overcoming a problematic multi-step synthesis from aminoacetamidine and sulfur monochloride. 35…”

“…Treatment of ethenes with [(NSCl) 3 ] in benzene at reflux afforded 1,2,5-thiadiazoles 83 in moderate to good yields (Scheme 39). 83,85,86 The reaction may undergo the chlorination at allylic or benzylic positions, especially if excess of the trimer is used. With trisubstituted ethene (Z)-ethyl 4-phenyl-3-benzylbut-2-enoate debenzylation takes place giving 4-phenyl-1,2,5-thiadiazole-3-carboxylate.…”

The interaction of 1,4-diketones with thiazyl chloride (NSCl)

“…A blank experiment showed that this urethane 4 was not converted into the thiadiazole 2 which is probably derived from the alkene and trimer 1. 3 The urethane 4 could result from a Michael-type addition of ethyl carbamate to the electron-deficient alkene, and the alkane so formed could be oxidised, possibly via N-chlorination. Indeed, heating E-1,2-dibenzoylethene with equimolar urethane in benzene and pyridine for 36 hours gave 1-ethoxycarbonylamino-1,2-dibenzoylethane in 74% yield.…”

“…1,2-Dibenzoyl -ethane, -ethene (E and Z) and -ethyne all react with the preformed trimer 1 in refluxing tetrachloromethane to give only 3,4-dibenzoyl-1,2,5-thiadiazole 2 in modest yield (40-44%) probably by way of cycloaddition or cyclisation mechanisms. 3,4 These substrates react differently with Katz reagent under 'standard' conditions [ethyl carbamate (4.5 mmol), thionyl chloride (4.5 mmol) and pyridine (1.5-2.0 mmol) in benzene (20-25 mL) stirred at room temperature for 30 min followed by addition of the substrate (1 mmol) and heating under reflux until the substrate was consumed (48, 36 and 4h respectively]. 1,2-Dibenzoylethane gave the same major product as with the trimer, 3,4-dibenzoyl-1,2,5-thiadiazole 2, in similar yield (45%) together with 5-benzoyl-3-phenylisothiazole 3 (13%).…”