Dipotassium cyanodithioimidocarbonate

The dipotassium salt of 3,5-dithio-l,2,4-thiadiazole (296) can be easily prepared by refluxing a solution of dipotassium cyanodithioimidocarbonate (295) with sulfur in methanol <82AHC(32)285). 

Cyanodithioimidocarbonate salts have become very useful reagents for the preparation of many 3,5-disubstituted 1,2,4-thiadiazoles. Dipotassium cyanodithioimidocarbonate (314) is readily prepared from cyanamide and carbon disulfide under alkaline conditions and is readily converted into the reactive thiadiazoles (315), (316), (317), (318) and (319), as shown in Scheme 112 (71JOC14). Alkylation of (314) produces derivatives of type (320) which react with chlorine or sulfuryl chloride to yield 5-alkylthio-3-chloro-l,2,4-thiadiazoles... 

HETEROCYCLES Copper phcnylace-tylide. Dichlorobis(benzonitrile)palladium. N-Dichloromethylene-N,N-dimcthylammo-nium chloride. Diiminosuccinonitrile. Dimethyl acetylenedicarboxylate. Dipotassium cyanodithioimidocarbonate. Ethoxy-carbonyl isothiocyanate. Ethyldiisopropyl-amine. Ethylene oxide. Hydrogen fluoride. Isocyanomethane-phosphoric acid diethyl ester. Lead tetraacetate. Lithium aluminium hydride. Methylhydrazine. Phosphoryl chloride. Polyphosphate ester. Polyphosphoric acid. Potassium amide. Potassium hydroxide. Tolythiomethyl isocyanide. Tosylmethyl isocyanide, Trichlo-romethylisocyanide dichloride. Trimethyl-silyldiazomethane. 

Dipotassium cyanodithioimidocarbonate (269) is readily produced from cyanamide and carbon disulfide in alkali, and affords the S-alkyl derivatives (280) in good yield upon treatment with a variety of primary and secondary alkyl halides.219,220 The action of chlorine converts the parent salt (269) to 3-chloro-l,2,4-thiadiazole-5-sulfenyl chloride(282,85-100%), and the bromo analog is similarly accessible.209,221,222 Dipotassium perthiocyanate (270, obtained from 269 and sulfur209) is chlorinated to the stable bissulfenyl... 

The authors initially investigated the synthesis of resin-bound 4-aminothiazole-5-esters, which were generated in two convenient steps starting fi om Merrifield resin (Scheme 8.3) by the reaction with dipotassium cyanodithioimidocarbonate followed by a condensation reaction with ethyl bromoacetate in DMF at 80°C using TEA as the base. The urea formation with a large number of isocyanates was then explored under microwave irradiation using /Pr2EtN in DMSO at 150°C. After the NaH-mediated cyclization and... 

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