Thiazolo-- and --thiadiazoles

Thiazolo-[2,3-c]- and -[3,2-6]-[l,2,4]thiadiazoles [CaNgS-CaNS].—Condensations of a-amino-N-heterocycles with chlorocarbonylsulphenyl chloride in the presence of an organic tertiary base can give rise either to a 2,3- or to a 3,4-fused [1,2,4]-thiadiazolone. Thus, 2-aminothiazole yields 2JT-thiazolo[3,2-b][l,2,4]thiadiazol-2-one in THF (see Vol. 3, p. 684). The isomeric 2,3-fused system is formed in ethanol-free chloroform. 2-Amino-A -thiazoline similarly yields 5,6-dihydro-thiazolo[2,3-c][l,2,4]thiadiazol-3-one, the structure of which has been confirmed by X-TQ.y analysis.  

2-Aminothiazole reacts with trichloromethanesulphenyl chloride to give a sulphenamide, which condenses with m-nitroaniline to give compound (44).  

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