Bromination reactions of 5-bromindanone, synthesis of brom and hydroxy derivatives

A rapid growth on the synthetic work of indenones has taken place in the last three decades. Indenones are useful intermediates in the synthesis of a variety of molecules. Bromoindenones are also valuable precursor for preparation of ninhydrin analogs, used determination of finger prints. Despite the considerable biological and synthetic interest in indenones and indenols, very few general and flexible synthetic routes to these compounds have been reported. A logical synthetic precursor is the corresponding indanone, but poor yields, irreproducibility, or decomposition of the starting material have made this route unattractive.In this study, the low temperature bromination reactions of 5-bromoindanone (3), molecular bromine and N-bromosuccinimide were investigated. Spesific and selective routes were developed for derivatives of bromosubsituted indanones. First, we studied the ionic bromination of 5-bromoindanone (3) with molecular bromine. The 2,5-diibromoindanone (27) was obtained as the sole product in high yield of 90%. The result of bromination of 5-Bİ and molecular bromine, we are obtained 2,2,5-tribromindanone 28 in high yield of %95. Then, we are obtained 2,5-dibromindanone (27) in the result of the low temperature bromination reaction of 5-Bİ (3) moleculer bromine. Second, the reaction of 2,5-dibromindanone (27), were the NaBH4, Me-OH and THF were obtained the derivative product of bromhydrin (30) in a yield of %100. Third, we were obtained dibromindanols asetoksi 31 in a yield of %100. Then the reaction of bromhidrinin (30) in dark with NaOCH3 and THF, N2 RT was done. We weren?t obtained the expected compound, we could not obtained the expected compound, instead we obtained (3) the starting matterialKey Words: photobromination, bromoindanones, bromoindenones