2-Benzylidene-1-indanones (BI) constitute a family of heterocyclic compounds with a wide range of pharmacological and material applications. Their structure and biological activity make them promising candidates for new bioactive entities and functional materials.

Preliminary results of new chemistry in this field are presented here, consisting of a) the transformation of (E)-2-(2-nitrobenzylidene)-2,3-dihydro-1H-inden-1-one (BI-NO2) into 4b,10,10a,11-tetrahydro-5H-indeno[1,2-b]quinoline (TIQ) and b) the transformation of methyl (E)-2- ((1-oxo-1,3-dihydro-2H-inden-2-ylidene)methyl)benzoate (MOIB) into 1'-(diisopropylamino)-2,2'-spirobi[indene]-1,3'(1'H,3H)-dione (DSI).

An acid-mediated aldolic condensation of 1-indanone with o-nitrobenzaldehyde provided BI-NO₂, which, when subjected to catalytic hydrogenation, led directly to the tetracyclic quinoline TIQ, as could be established from its analytical and spectroscopic data. Its HRMS confirmed its molecular formula C₁₆H1₅N, and its ¹³C NMR spectrum includes signals from 8 aromatic protons, as well as signals from 2 tertiary aliphatic carbons and 2 secondary aliphatic carbons.

The formation of this quinoline TQI must be the result of several successive spontaneous reactions.

On the other hand, basic-mediated aldolic condensation of 1-indanone with o-methoxycarbonylbenzaldehyde provided MOIB, which, when treated with LDA, led to the formation of the spiran derivative (DSI), whose molecular formula was confirmed from its HRMS, and its 13C NMR shows signals of 8 aromatic carbons, together with the signal of its spirocarbon and the signals of the two carbonyl carbons.