The reactivity of halogen in the benzene ring and also in the 4-position of the sydnone ring of various arylsydnones towards nucleophiles has been investigated. The course of ring- fission in 4-halogenosydnones induced by primary amines differs from that of secondary amines. The reaction in the latter case provides a preparative route to diamino-acid amides. Several new halogenosydnones are described.
![(Z)-3-(4-ethoxyphenyl)-2-[4-(4-fluorophenyl)-1,3-thiazol-2-yl]prop-2-enenitrile Structure](https://image.chemsrc.com/caspic/234/5319-47-1.png)