sydnone imines

https://doi.org/10.1351/goldbook.S06206
@I02957@ of @S06207@ (i.e. having an imino group in place of the exocyclic oxygen atom).
S06206.png
(These structures represent only two canonical forms.)
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1371 [Terms] [Paper]