Cyclisation of 2-(nitroacetyl)benzoic acids
Abstract
The cyclisation of 2-(nitroacetyl)benzoic acids (1) gives mixtures of (E)- and (Z)-3-(nitromethylene)phthalides(4), unambiguously identified by n.m.r. spectroscopy. Rearrangement of either isomer with tertiary base provides a novel route to 2-nitroindane-1,3-diones (5).