Synthesis of Benz[f]ninhydrine from Benz[f]indanone

Benz[f]indenones are potentially useful building blocks in organic and organometallic synthesis. However, their chemistry has not been extensively explored. Recently, benz[f]indenones were used as important starting materials in the synthesis of kinamycin antibiotics, which showed excellent activity against gram-positive bacteria. Benz[f]indenones and benz[f]indenes were used as target molecules for computational chemistry. It was reported that benz[f]indene derivatives exhibited fluorescence in the blue region (emission maximum around 350-410 nm). Bromination of carbonyl compounds is an important transformation, as the resulting ? -brominated products are versatile intermediates in organic synthesis.In this work, we report bromination reactions of benz[f]indanone (1) using different reaction conditions to synthesize brominated derivatives. We prepared a variety of brominated derivatives (2.44, 2.45, 2.46, 2.47, 4.1, 4.2, 4.3, 4.4), and accomplished the first, quantitative and highly regioselective synthesis of all brominated derivatives. Tricarbonyl 2.49 was obtained from 4.6 with Br2 under radicalic conditions at room temperature.Keywords: photobromination, bromobenz[f]indanones, bromobenz[f]indenones