Optional N-locant for isocyanate

[IngvarLa]

An N-locant is not expected for isocyanate/isothiocyanate, but in some cases they have been added; ChemDraw accepts them. I have only seen a few examples, but it seems relatively harmless to add. Simple case, ChemDraw accepts all of: N-phenylisocyanate N-phenyl isocyanate N-(phenyl)isocyanate N-(phenyl) isocyanate as equivalent to phenylisocyanate