Thiophosgene thioacylation

The 5-substituted 1,2,3,4-thiatriazoles 758 are prepared by the generation of intermediate azidothiocarbonyl compounds 757 followed by 1,5-electrocyclic reaction (Scheme 326). The intermediate compounds 757 have never been isolated they can be generated by treatment of derivatives of thiohydrazides 756 with either nitrous acid or with arenediazonium salts, and in reactions of thiophosgene (or dithiocarboxylates) 755 (X = Cl, SR) with either sodium- or trimethylsilyl azide (Scheme 326) . For example, thiatriazoles 760 can be prepared in high yields by the reaction of or A-thioacyl dithiophosphates 759 with sodium azide (Scheme 327) <2002J(P1)1271>. 

In contrast to thioacyl chlorides, thiophosgene, CSCh, is readily accessible and conveniently handled making it an important reagent in the synthesis of thiocarbamoyl chlorides (15 ClCSNRa), 0-alkyl thiourethanes (ROCSNR 2), and thioureas (R2NCSNR2) (c/. Volume 6, Chapter 2.8). ... 

Aliphatic thioacyl chlorides, e.g. Bu CH2C(S)Cl and Bu CHClC(S)Cl, can be obtained by addition of hydrogen chloride or chlorine, respectively, to the thioketen Bu CH=C=S, generated by flash pyrolysis of 4-t-butyl-l,2,3-thiadi-azoles or by direct reaction with the heated thiadiazole. The addition of hydrogen chloride to the alkynethiolate ion Bu C=CS also gives the thioacyl chloride Bu CHaC(S)Cl. Addition of thiophosgene to the enamine Mc2NC(Bu )=CHa... 

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