The name given is not standard.
Fluoran itself is a spiro compound with two components:
(it's strictly an isobenzofuranone, but I'm lazy to type that multiple times.)
Because of the nomenclature rules of spiro compounds (which I'm sure someone will come along and tell you all about), the atoms in the benzofuran system are labelled 1-7 and those in the xanthene system are labelled 1'-10', with an apostrophe.
Atoms 1 and 2 of the benzofuran system are both within the furan ring. If I am not wrong, atom 1 is the carbonyl carbon, and atom 2 is the ring oxygen. The given name, that starts with "1,2-benzo", therefore makes no sense as you cannot fuse a benzene ring to atoms 1 and 2 of the benzofuran system.
After a little bit of Googling, I came across this compound: 6'-(Diethylamino)-1',2'-benzofluoran. I think with the apostrophes, it makes much more sense.
The numbering within the xanthene system parallels that of anthracene:
Having "1',2'-benzo" means that you have an additional fused benzene ring to carbons 1' and 2'. The 6'-substituent also makes sense. Chances are if the paper you were reading labelled the xanthene atoms with 1-10 without apostrophes, the 6-amino group should be a 6'-amino instead. Your desired structural formula is probably
ChemDraw's name to structure generator gives this molecule when you input 6'-(N-ethyl-N-isobutylamino)-1',2'-benzofluoran. The amino group, which is just an ordinary substituent, should probably be a prefix to "benzofluoran" which is the parent compound.
I am sure in due time someone will come along and give you all the official IUPAC rules but I figured that if you just wanted the structural formula, my not-very-rigorous explanation would suffice.