General procedure for the synthesis of 5-bromo-1H-indene from 6-bromo-2,3-dihydro-1H-inden-1-ol: 170 g of 6-bromo-2,3-dihydro-1H-inden-1-ol, 1.2 L of hydroxybenzenesulphonic acid, p-toluenesulphonic acid, and 8 g of catalyst were added to a reaction flask for 3 hours. After completion of the reaction, benzene was removed by distillation. The crude product was purified by fast chromatography to give 148 g of 5-bromo-1H-indene (in the form of coral oil) in 95% yield.
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